Questions on: Soil

Ron Smith, Horticulturist, NDSU Extension Service


Q: I built a new home and had some topsoil hauled in for my yard last fall. The soil looked fine at the time. Now it appears as though there may be some alkali in it. The areas of the yard that are the driest have a white, crusty substance on the surface. The wet dirt is black. Is it alkali? If so, what can be done about it short of removing it? I live on a river bottom with sand, so black soil is needed for a lawn. (e-mail reference)

A: Find out how bad the soil is by having the local land-grant university test it. Most have a soil testing lab. For a nominal fee, it will provide you with a soil test for pH, P, K, soluble salts and organic matter content. I suspect that you will find the pH to be quite high (8 or more), and also a high soluble salt reading. I'm also willing to bet that the soil is very poorly drained. You can try adding copious amounts of organic matter to the soil, along with a generous amount of sand, to correct the problem. However, if that is needed, you probably are better off getting this stuff hauled out and replaced with some decent topsoil. Get it tested before you have it delivered this time.


Q: I have had a problem getting things to grow in my garden since I moved here in 1999. The previous owners had the same problem. I live close to the Bois De Sioux River south of Wahpeton. The garden is surrounded by trees on three sides, but it has full sun until very late in the afternoon. The closest trees are about 25 feet away on the north side. I had a soil test done in 2001 that showed everything was great, except I had no nitrogen. I starting tilling in grass clippings and leaves for organic matter, but was told it depletes the nitrogen. I added nitrogen every fall, which seemed to work for a couple of years. Last year I was back to the same problem of things not growing, so I did another soil test. This time I had too much nitrogen and dissolved salts. The garden has decent drainage, but I hauled in two truckloads of dirt to help with drainage. Could having my garden right next to my septic system drain field be affecting the dissolved salts? I installed the septic system in 2000. At my previous residence, I always had a lush garden and did all the same things I have done with this garden. What can I do different or do I need a different location? Gardening has always been relaxing to me. However, when you can't get anything to grow, it gets to be a waste of time and adds more stress because of the frustration! Thanks in advance for your help! (e-mail reference)

A: The high soluble salts definitely will create a problem in trying to grow vegetables. The septic system is a major source of your problem. If the salts cannot drain away, they accumulate in heavy soil and cause problems with seed germination, subsequent growth and the production of a harvestable crop. Many gardeners are finding success with raised bed/square-foot gardening. They are above the surrounding soil and create their own "designer soil" with good drainage and low salt content. You also can tweak the nutrient levels to suit the crops being grown. I would suggest this as an alternative or moving the garden to another location away from the septic field.


Q: We are having our sewer mound removed this spring. Instead of reseeding with grass, the site would be a perfect area for a large vegetable, herb, annual and perennial garden. New dirt will be hauled in. Is it safe to plant edible produce where this mound used to be? (Minot, N.D.)

A: No problem with planting a garden on the old site as long as there is no direct contact with human waste. Plant and enjoy!


Q: I'm working on a project in Devils Lake. The soil conditions are saline/alkaline. I would greatly appreciate any input for reseeding areas with these conditions. One comment I've received is to try wheatgrass? (e-mail reference)

A: That is a good suggestion. But I would make it a mixture of crested wheatgrass, sheep fescue ('Covar' cultivar) and alkaligrass ('Fultz'). If you are talking about a large area, I would suggest contacting Agassiz Seed in West Fargo to make up an appropriate mixture for you. If this doesn't grow for you, then I would revert to artificial grass!


Q: I have used Epsom salts on my garden tomatoes every year to produce beautiful plants and plenty of tomatoes. My relatives in Connecticut have tried the same thing, but it doesn’t work. They see little or no difference in growth or fruit production. Can you tell me why? They swear they are following my recommendations. (Fargo, N.D.)

A: There is quite a leap in environmental conditions and soil from Fargo to Connecticut! Epsom salts is nothing more than magnesium sulfate. Both elements, magnesium and sulfur, are used by all plants for growth. Fargo soil is typically alkaline, while New England soil, I would bet, is acidic. You probably are experiencing the luck of the lot. Your soil is deficient in either or both of these elements. Your relative in Connecticut probably has enough of both, so using Epsom salts won’t have an effect. Both of you should have your soil tested at your land-grant university. NDSU for you and at the University of Connecticut for your relative. That way, both of you can make intelligent decisions about what it is you need to add to the soil to produce your best crop of whatever it is you want to grow.


Q: I bought a large bag of Miracle-Gro potting soil. I used about one-fourth of it and then stored the rest in a watertight container. I went to get it to add to some soil for tomato plants, but the Miracle-Gro was full of black ants. Will it hurt the tomato plants? (e-mail reference)

A: I never have known ants to hurt tomato plants, so I would go ahead and use it. The ants will settle into the surrounding environment or be preyed upon by the local population, so you should have nothing to worry about.


Q: I am having problems with my vegetable garden. The peas came up nicely, but it didn’t take long for the leaves to start curling. I dug some up and found rotten roots that were brownish and soft. What would cause that? I also am having problems with my cucumbers. They also came up nicely, but then the leaves started curling. They haven’t died, but aren’t growing. These plants also have rotting roots. We are very dry here, but I try to water once a week. The only thing I have done differently is that last fall I put a load of manure on that spot in the garden. This spring, I took most of it to other gardens, so there wasn’t much left when I tilled it. There are self-seeding flowers coming up in the same spots as the cucumbers and peas, but the flowers look fine. Any ideas what could be wrong? (e-mail reference)

A: The manure brought too much salt to the soil. The salt is killing the seedlings and transplants. The flowers that are volunteering are tolerant to high salt levels. With copious watering, the salts should decrease during this growing season. You successfully should be able to plant a garden next spring.


Q: I am looking for design plans for an elevated gardening bed. The care facility at Rolette is interested in building gardening stands that residents in wheelchairs could garden. Could you direct me to plans for raised beds that would accommodate wheel chairs and also recommendations on what soil mixture to use? (e-mail reference)

A: One book has it all. The book is "Square Foot Gardening" by Mel Bartholomew. It is available in book stores.


Q: I’m checking to see if you have any information on what is best to add to the soil to help loosen it for a flower bed. (e-mail reference)

A: You can try peat moss. It can be bought in bales at your local garden center.


Q: I was in the yard today and noticed the lawn has little patches of black dirt, such as an ant hill. The piles are an inch and a half in circumference and about a quarter-inch high. The dirt is dry on top, but wet as I dig down, although I didn't dig down very far. Any suggestions would help. (Valley City, N.D.)

A: Welcome to the club! I believe the piles of dirt were created from the alternate freezing/thawing of our soil, possibly enriched by a high night crawler population from the previous year. To correct the problem, I suggest rolling the lawn with a ballast roller half filled with water. Do this when you can walk across the lawn without leaving a wet footprint.


Q: A couple of years ago I put a raised flowerbed in my backyard. We brought some top soil in from our farm and I planted tulips and perennials in it. Last fall I wanted to plant some more tulips, but the soil was so hard I couldn't get a hole dug. Is there anything I can add to the soil to loosen it? I don't want to dig everything up if I don't have to. Any help you can give me would be appreciated. I have learned more from your columns than anywhere else. It's the first thing I look for when our paper comes. (Ashley, N.D.)

A: Sandy loam is always the best soil to use for raised beds. Add a lot of organic matter, preferably in the form of sphagnum peat moss. Work the organic matter into the bed, but don't worry about adding too much. Keep working it into the soil until it gets to the consistency with which you want to work. Avoid sand unless you are able to make the proportion of sand 80 percent or better. Thank you for the nice comment about the column. I appreciate you being a faithful reader and I am glad you find the information useful!


Q: If a cat has been using the garden as a litter box, what needs to be done to the soil before it can be used to plant vegetables? (e-mail reference)

A: I would screen the soil down to a depth of 6 inches to be sure that all the droppings are removed. After that, incorporate generous amounts of sphagnum peat moss to further dilute the soil.


Q: What is your opinion on mycorrhizae and products that claim that they can increase the success rate for transplanting trees? Have you done studies on these products? I plan to put bareroot stock in containers and have been looking for a soil mix recipe. Do you have that information or can you steer me in the right direction? (e-mail reference)

A: Unless the plants are going into a sterilized media completely, save your money. While the products will not hurt anything, we have not seen any evidence of these products making a difference. Cornell and the University of California have standardized formulations that are soilless. The one I like better has some soil in it and is considered a classic organic soil mix. The mixture has one-third mature, screened compost or leaf mold, one-third garden topsoil and one-third sharp sand. This mix results in a potting soil that is heavier than modern peat mixes, but has good drainage. Compost has been shown to promote a healthy soil mix that can reduce root diseases. Perlite can be used instead of sand. Organic fertilizer can be added to this base. If perlite is used, understand that over time, it tends to separate and migrate to the surface. With sand, make sure it is sharp or coarse, not fine.


Q: I have a landowner who has a newly planted one-row shelterbelt of flame willow trees. The trees are showing signs of having a high pH level (yellowing and smaller leaves). He would like to neutralize the soil. What would you recommend to amend the soil to lower the pH? (e-mail reference)

A: I promise you it would be an act of futility. Lowering the pH level in highly alkaline soils is like attempting to empty Lake Superior with a coffee cup! The soil should be tested for pH, N,P, K, soluble salts and possibly the iron and sulfur content. Deficiencies in nitrogen, iron or sulfur can cause the symptoms you describe. It would be easier to nail down the deficient element through testing. If it turns out to be a microelement, corrections can be made by adding chelated forms to the soil.


Q: My brother has just moved here from Illinois. He is a gardening enthusiast. He would like to know what the average date of the last frost is in the spring and the average date of the first frost in the fall. (Leeds, N.D.)

A: Going by averages is a little dangerous at times. The data I have is from Minot, so give it a day or two either way. The last frost in the spring is approximately May 31 and the average date of the first fall frost is Sept. 2. That gives your brother about 90 frost-free days of gardening to enjoy, if the averages hold close.


Q: I have a very clay soil. Cabbage, broccoli and cauliflower grow well in my garden, but the cucumbers turn yellow and do not produce very well, if at all. I’ve brought in sand in the past. Using sand, the onions, potatoes and peppers do well, but the sand disappears after a year. The garden is surrounded by grass and is on flat ground, but there is a hill about 30 feet away. We brought in more soil from Streeter because it is sandy. Can I “bake” the soil to destroy the weeds or would it decrease the nutrients? (The soil was full of quack grass.) How can I keep the sand from leaving the garden? Why don’t cucumbers grow in my garden? Is there a missing nutrient? (Jamestown, N.D.)

A: Forget using sand. Instead, use large amounts of sphagnum peat moss to work into the upper 6 to 9 inches of the soil. “Solarizing” the soil will help get rid of some of the weeds, but not all because some weeds are heat resistant until the temperature gets above 170 degrees. The reason your cucumbers turn yellow is probably because of the high pH and/or high clay content. The addition of peat moss should go a long way toward making nutrients available to the plants.


Q: How do I test the soil for pH? Is there a test kit I can buy or do I have to take a sample to a county Extension Service office? (e-mail reference)

A: The test kits that can be purchased are not reliably accurate and have limitations in range. You are better off contacting the local Extension Service office to get a bag or two from it to use to collect the soil. Then order a nice snapshot of N,P,K, pH, SS (soluble salts) and the organic matter present.


Q: The soil in my subdivision is clay with a fairly balanced pH. About four years ago, I planted a maple intending for it to become my large front yard centerpiece. It is has not grown very much since planting. Its branches don’t seem to be spreading and its leaves never make it to fall. During the hot part of summer, the leaves develop a brown fringe that looks like they are dry, but remain supple to the touch. Eventually the brown fringe creeps inward until the leaves drop. I water it regularly. Is there a fertilizer I can use? (e-mail reference)

A: Leaf scorch has a lot of causes. The basic problem is that the roots can't get enough water to the leaves. Some of the causes include highly saline soils, flood or drought, soil compaction, nearby excavation, root rot, severe temperatures, limited room for root growth and transplanting. It may be starting with a mid-summer drying of the soils, but you respond to that by watering. Are you over-watering? Clay soils tend to hold water really tightly, but when they get waterlogged, then there's no oxygen available to the roots. You said that the soils have a fairly balanced pH; but what about salts? Is there salt in the water that you use for irrigation? Because you live in a new subdivision, I'm curious about the soil used in your yard. Sometimes, builders will strip the topsoil away and sell it, then come back and just put a thin layer of sod back down. This leaves poor subsoil to grow trees. Also, when trees have been recently transplanted it takes them a few years to adjust to the new site, approximately one year for each inch of caliper (diameter at ground line). (JZ)


Q: I have purchased several 75 foot long soaker hoses. The label says a hose will emit one gallon per foot per hour at low pressure. How far will water soak into the ground on each side of the hose? I want to space the hoses the proper distance apart so I can be assured that all the plants get enough moisture. Also, how many hours should I water for deep soaking and how many times per week? The soil is fairly sandy soil so I have good drainage. (Cooperstown, N.D.)

A: Sandy soil has good vertical percolation rates but not very good horizontal hydraulic conductivity. You will have to experiment with spacing to see how far it will spread. I suggest starting out with the hoses about 12 inches apart. Keep in mind that what you see taking place on the surface will not equal what is going on below the surface. Water in sandy soil follows a fairly narrow path down through the profile. Clay soil spreads out in a "belly" like fashion. As far as timing, I would suggest leaving it on, initially, at least for three hours. After that, check to see how deep the water penetrated into the soil and how far it spread. How often you water depends on whether or not the beds are raised, in full sun, facing south, exposed to prevailing wind forces or if you mulched. I suggest mulching to conserve water and control weeds.


Q: My tree farm has good loamy soil but it is in a low area where frost has caused damage (mainly various ash varieties) the last two springs after new leaves appeared. Is there any product that can provide protection or are there other methods that will work to prevent frost damage? (E-mail reference)

A: Other than relocating them, not much can be done. Low areas will be frost traps and do damage to crops in late spring. If covering them up with a frost blanket is not an option or if you cannot turn sprinklers on when frosty nights are anticipated, then I don't know what else you can do that would be effective. Sorry!


Q: My question has to do with my pothos plant. The other day I bought soil and repotted it into a larger pot but the soil looks awful. It is not soft and I cannot put my finger in it. Can I change the soil without harming the roots? How would I do that? Do you think Miracle-Gro is the best soil? I bet you can tell I am new at this plant thing. (E-mail reference)

A: Everybody has to start somewhere. I learn something new about plants almost every day. Try to find Miracle Gro or Schultz's potting soil. I have used both with great success. You can wash the soil off the roots and repot with one of the soils I mentioned or something similar. The soil should be porous, high in organic matter and either be sterilized or pasteurized (It should say on the bag).


Q: We have a sand play area that we would like to turn into a garden plot. It has about 4 to 6 inches of sand. I intend to put edging around the plot and have some black dirt hauled in. I'm wondering if I can leave part of the sand as a base? How much black dirt should I put on top? Should I try to mix the sand into the black clay that is underneath the sand? Would I be better off getting rid of all the sand and mixing organic material into the gumbo instead of hauling in dirt? Also, the garden that I am using now is in a low spot with poor drainage. I'm planning on turning that in to a raspberry patch. Would it be a good idea to mix some of the sand into that area before I plant? (Fargo, N.D.)

A: The less stratification of the various soil components, the fewer problems. To get the best garden spot developed, remove all the sand, bring in some sphagnum peat moss, till it completely into the existing clay soil, and bring in some more to raise the area from the surrounding terrain. Raised bed gardening will provide superior drainage, earlier warm up of the soil, and in general, better vegetable crops. Sand mixed with clay is an incompatible combination unless it is at least an 80 to 20 ratio. It would need to be 80 or more parts sand to 20 parts clay. I would prefer to work sphagnum peat into the clay because the results will be more predictable.


Q: Is there a product called Goal that can be used as a soil sterilant around trees? A farmer we know has some young transplanted trees and some older more mature trees that he would like to spray a sterilant around. Are there any other products that can be used for that purpose? Are there any drawbacks or adverse effects that a person should be aware of? (Kragnes, M.N.)

A: Goal can only be applied by a licensed applicator. It is not considered a soil sterilant, but rather a grassy/broadleaf weed killer. While it can be used around trees, restrictions exist, such as not spraying over the top of deciduous trees. The best bet would be to apply Roundup around the base of the trees, making sure that no direct or indirect drift got onto the foliage. This would take down everything that is green without sterilizing the soil, which you don't want.


Q: What is the difference between lime, calcium, and bone meal? How should they be used and for what plants? (New Rockford, N.D.)

A: Good question: Lime is either calcium carbonate, calcium sulfate (gypsum), calcium hydroxide (hydrated lime), or calcium-magnesium carbonate (dolomite). All have slightly different purposes for horticultural use, and as you can figure out, all come from the earth. Bone meal is an animal by-product, and comes either raw or steamed. The difference is the steamed bone meal that is commonly used in horticulture has most of the gelatinous material removed through the steaming process while the raw bone meal does not. Bone meal is a rich source of calcium as are the many forms of "lime." To "lime" a soil means to add crushed limestone (passing through #60 mesh screen) to adjust the pH from an acidic to a more alkaline or less acid state. This is a chemical reaction that takes time to react, often over several years of application. Dolomite is a good one to apply to provide the essential elements of calcium and magnesium; gypsum supplies the elements of calcium and sulfur, and cancel each other out for the most part, neither raising or lowering the pH of the soil.


Q: After spending a lot of time last year looking up blossom end rot and finding that it means we need to add lime to the soil. I looked and looked and could not find lime for the garden. I finally did plant two plants and added plenty of the so called tomato plant food, thinking that just might take care if the problem. Well we got about four tomatoes that did not have the blossom-end rot. This year I have looked and asked about lime and all I can find is lime for pickling. Now I wonder if this would work and if so how much to put in the area for the tomatoes. I have a planter box that will hold two plants. If this will work and you can tell me about how much to use I sure would appreciate it. I am wondering why it is not available and more people do not use it as I hear so many talk about the bad tomatoes that they grow. (Forman, N.D.)

A: Blossom end rot is the result of calcium failing to reach the ends of the tomatoes during initial cell formation. It is caused by water availability fluctuations (dry then wet), damage to the roots that causes them to have limited ability to absorb calcium and, believe it or not, cultivar characteristics. Some are more vulnerable to it than others. I would forget about adding lime. Our soil is plenty high in calcium. Try to plant the tomatoes when the soil is warmed enough, plant them deep, mulch with peat moss, water evenly and try not to get too close to the roots when cultivating around the plants. Also, it is usually only the earliest tomatoes that are most subject to BLR. Try my suggestions and let me know how everything turns out.


Q: Do you have a formula and procedure for using chlorine bleach or Lysol to sanitize planting trays? (Cando, N.D.)

A: Use either a 10 percent bleach or Lysol concentration. That would be nine parts water to one part of the chemical. Simply dipping them into the solution for a few seconds and allowing them to air dry does the trick. Good sowing!


Q: This is kind of an indirect question but it does fit into the field! I have a standard walk-behind tiller and am considering retiring it and getting a small Mantis lightweight tiller instead. I never believe all the advertising behind a product so am looking for people who may have had experience with it. Do you have an opinion? (E-mail reference)

A: No problem. We use a Mantis on the campus beds, and while we don't do a "one-hander" in our heavy soil, it does do a very satisfactory job.


Q: I had our garden soil tested by your lab on April 27 and received the report dated May 1. I'm very grateful for the quick response. The report says that our soil is "critically low in nitrogen, and moderately low in potassium." They suggest adding wood ashes or potassium sulfate for the K, and ammonium sulfate for the N. I went to a nursery and they could not find ammonium sulfate, though they called some other sources. Have you a suggestion about what I could use, or where I can find it? (Linton, N.D.)

A: There are several sources of nitrogen. I simply mentioned ammonium sulfate thinking it was readily available, but apparently it isn't locally. Here are some others to consider, one (if not more!) of which should be obtainable locally: Ammonium nitrate - 34% N Urea - 46% N Urea-Formaldehyde - 38% N Sulfur Coated Urea - 31% N Note that these sources are all higher in N than the ammonium sulfate. You should adjust your rate of application accordingly. Instead of the 4 to 5 pounds of material to be added to 1000 square feet and worked into the soil, you would want to reduce that to 2 to 3 pounds per 1000 square feet.


Q: I have this moss that is growing along the drip line on the north side of the garage. It has spread to a width of 2 feet, choking out the lawn grass. I tried spraying with copper sulfate and it did not work, but maybe it was not mixed correctly. What should I use to kill this moss? (Napoleon, N.D.)

A: Moss is usually indicative of poor nutrition, wetness and shade. Control involves pruning low branches for better sunlight penetration, reducing irrigation cycles to reduce moisture, power raking and/or core aeration to improve water infiltration, and applying of superphosphate (0-20-0) at 3 to 5 pounds per 1000 square feet to kill the moss. Bring the nutrient status up to par with a complete fertilizer and re-seed with the appropriate mixture, which would have a high percentage of fine leaf or creeping red fescue in it (at least 55 percent).


Q: I mixed up my own soilless mix for starting seeds using three parts peat moss and one part vermiculite. Now I have what appears to be damping off disease. I have several flats growing under lights, and one or two plants keel over every day. Is there anything I can do besides dumping them all in the garbage? I thought soilless mix wasn't suppose to have damping off. (E-mail reference, Driscoll, N.D.)

A: The pathogen can be seedborne as well, and given the right conditions ( damp, warm, no-air movement environment) the damping-off fungus will become active. I suggest setting up a little fan to move the air across the seedlings and stretch the time between the waterings a little, trying not to splash when you do water. If the fungus appears to be migrating from one end of the flat of seedlings, cut out a couple of rows, media and all, and dispose of it.


Q: Do you have the instructions for sterilizing soil in a microwave? (E-mail reference, Minot, N.D.)

A: Take a pint of soil, place it in a ziplock bag, moisten ( not soak) and place in the microwave, with the bag open, for 2.5 to 3.0 minutes. That usually cooks any unwanted things in there pretty well. If it isn't too hot to handle, then do it again.


Q: In the last six months I have purchased four different brands of "ready-to-use" potting soil, where nothing had to be added before transplanting plants. The end result in all four cases of transplanting household plants has been fungus gnats infesting the plants, and subsequently the office where I work and my home. All four brands were infested with these bugs. In at least one case, five months later, I am still battling these pesky bugs at the office. I no longer plan to buy these "ready-to-use" products. I would prefer to make my own mixture, if this minimizes the risk of these small bugs causing such a huge nuisance. What are your suggestions for "homemade" potting soil mixtures for houseplants? I would like a recipe that works for most household plants, if you have one. Can you tell me if there is still a risk, in mixing various soil products for houseplants that still would result in these pesky bugs appearing? Does any product come sterilized so this won't happen? (E-mail reference, Jamestown, N.D.)

A: I'm sorry to hear that you have had the fungus gnat problem! I have used Miracle-Gro and Hyponex potting soil in the past with no problems. Here is what I suggest: purchase one of the commercial blends, then "bake" it in the oven for 30 minutes at 180 degrees. That will kill anything in there. Be sure the soil is moist before baking for maximum heat penetration. Once cooled, you will then have an excellent potting soil. This is far easier than trying to put the components together yourself and still having to bake the whole thing to make sure it is "clean."


Q: The last three years I have had what our county agent calls leaf blight. The leaves on the cukes, cabbage, and melons dried up and got lacy looking holes, then the plants died. He suggested spraying with a multi-purpose fungicide. I did that every 10 days, but I didn’t like eating the vegetables with all that spray on them. Is there anything else I could do? If I changed the soil in my garden spot would that be a solution? (Kramer, N.D.)

A: Changing soil and rotating your planting sites will certainly help. Also, try to order seed varieties that are known for disease resistance. Irrigation practices can play a big role in disease development as well. Drip irrigation delivers a consistent amount of water without splashing the foliage. Finally, avoid working the garden when the foliage is wet from dew or rain. Avoid vigorous cultivation too close to the plants to prevent root or foliar damage.


Q: I have a large garden and have had good luck in everything I planted, but the last two years the garden didn’t amount to anything. The vegetables came up good, but they didn’t grow any more. I use well water to water the garden, not city water. I have put dry leaves, mowed grass, and compost on the garden, but it didn’t seem to make a difference. Is there some kind of fertilizer I can put on? What do you suggest? (Jamestown, N.D.)

A: Start with a soil test. Send a pint of soil in a zip-lock bag, to the NDSU Soil Testing Lab - Waldron Hall, Fargo, ND 58105. I will then interpret the results and advise accordingly. Request N, P, K, OM, pH, and SS. The charge will be $20-$25 for each sample.


Q: I had a problem with blight in my garden last year. If I move my flowers and tomato cages to another location, do I need to worry about spreading the blight to the new site? (Pettibone, N.D.)

A: Yes, you will most likely carry the pathogens to your new site, unless you follow extremely good sanitation practices. This is possible with the cages but not likely with the plant material. However, keep in mind that the new location may not support pathogenic activity because of better drainage, antagonistic microbes, etc. Give it a try -- it is likely to be better than the old site.


Q: We have a paper shredder and have been doing a lot of our old magazines, among other things, and I was wondering if we can add the shreds to the compost or use it for mulch. Is the color ink a problem? We are organic gardeners. (E-mail reference, Carrington, N.D.)

A: As far as I know, the color ink is not a problem, although there may be some publications that are not adhering to the non-lead base in their printing. If in doubt, don't use it. Newsprint is o.k. If it is just a few magazine publishers, you might contact them and find out if their production process uses lead or not.


Q: I have access to worm castings from a worm farmer. Could they be mixed with the starter mix I use in my greenhouse or would it be too rich? The county agent said disease could also be a problem. Would it be best if I waited and used it in the transplant soil mix? (E-mail reference, Minot, N.D.)

A: Worm castings would be best used in the transplant mix. Your plants should take off beautifully after that.


Q: I have a grey fluffy mold growing on the topsoil of a few of my indoor houseplants. Will spraying lysol on the soil to kill this mold hurt my plants? (E-mail reference, Charleston, S.C.)

A: The mold is a saprophyte, which is a fungus that lives on decaying organic matter in your container. It posses no threat to your houseplant and usually responds to surface cultivation and air movement. I am not sure what effect Lysol would have on your houseplant, so I wouldn't take a chance. Simply scratch the surface and turn a fan on the plant, and allow the surface of the soil to dry between waterings. If this fails to work, simply scrape off the top layer of soil and replace with fresh, pasteurized material.


Q: I was reading one of your columns and you said to replant a peace lily in a high-humus planting soil. I have one that needs to be replanted, but when I went to get some planting soil I could not find one that said it had a high percentage of humus soil. What do I look for on the label?

When I repot the peace lily do I need a deep pot, or will a more shallow one be better? Also, do the brown trunk-like things that the leaves come out of need to be put deeper, or should I leave them sticking out as high as they are? (Forman, N.D., e-mail)

A: I know it is tough to sometimes find the high-organic potting soil. If you cannot find one labeled so, then use African violet potting soil, which has sufficient organic matter in it. You could also purchase what is on the local market and cut it with about 50 percent by volume with peat moss.

I would get a large, deep pot to provide more stability. Peace lilies can get fairly large. Plant them up to that point on the corm where the leaves originate. Keep the media moist but not saturated, and provide the plant with bright, diffused light for flowering. Do not set in full sunlight. Fertilize about every two months.


Q: When a granular form of fertilizer or nitrogen is added to an existing flower garden, do you just sprinkle it on the surface and water it in? Will the fertilizer eventually trickle down to those roots, or do I need to do something different around those plants? I want to be sure that all my flowers get what they need as not all have done so well the last year or two.

Also, do I need to apply the nitrogen more than once a summer?

One more question! I often read about how many gardeners are always incorporating organic matter into the soil. I add peat moss to my soil whenever I plant new plants, but how does one incorporate organic matter around existing plants? If I dig around the plants do I risk damaging roots? Is it good enough just to spread the organic matter across the surface? (e-mail)

A: Nitrogen sprinkled on the soil surface as a granular fertilizer will move into the soil profile and become available to the roots with the irrigation water or rain. Of course, if the soil is as hard as concrete, it will simply wash off. If it has good tilth, it will work well.

During a normal growing season (whatever that may be!) it is a good idea to apply nitrogen-based fertilizer about once every four to six weeks, assuming you are going to water and care for the planting on a regular basis. I wouldn't go beyond Aug. 1, however, as it would mostly be wasted.

If you work organic matter into the soil away from the roots of the plants and simply spread it around the plants that are already established, that will benefit the plants and the soil greatly.


Q: We recently moved to a different home and are anticipating planting a vegetable garden. Presently there is no garden plot in the yard. We realize a garden's first year may not be its best, so what should we consider in locating our garden and what should be done to best prepare the soil? (Fargo, N.D.)

A: Refer to "Everybody's Garden Guide" (H-618), a publication of the NDSU Extension Service. You can read it over on these waning winter days. In addition keep the following pointers in mind:

1.The garden will need about six hours of direct sunlight a day for good production. Given a choice, morning light is better than afternoon sunlight.
2.Turn the soil over, have the soil tested, and incorporate organic matter, such as peat moss or compost, in the
top 6 inches.
3.Allow the weed seed time to sprout before planting--about seven to 10 days. Then hoe shallowly. Repeat,
then plant.
4.Plant for canopy cover to reduce weeding frequency after the first month.
5.Avoid watering on the foliage.
6.Select varieties of vegetables that are touted for their earliness and disease resistance.


Q: My garden is made up of heavy soil, mostly clay which gets hard to work with. I have sawdust available. If I spread this on the garden and rototilled it in this spring, would it help or hinder the soil? (Moorhead, Minn.)

A: Sawdust is an excellent soil conditioner. I've used it several times in my career as a horticulturist. The first time I used it, the sawdust was as fresh and white as the snow that is presently outside. Within a month, the plants were chlorotic. Being just a 15-year-old at the time, I didn't know what was happening. The extension agent came out and told me the planting needed extra nitrogen because the sawdust was too fresh. I applied urea, and that took care of it. The two other times I have since used it, the sawdust had weathered somewhat, so there was no nitrogen tie-up.

This advice is assuming, of course, that the sawdust has come from untreated lumber. If the lumber has been pressure-treated with a wood preservative, I do not suggest using it.


Q: I have a question about one of the trees in my yard. I am not sure what kind it is. It is a small tree that starts out in the spring with green leaves that quickly turn purple. The leaves stay purple until fall and are long and slender.

After the leaves dropped this fall, I noticed three branches had a dark growth on them. It is an ugly black thing that has clearly grown around the branches. Is this a bug or a disease? What can I do about this? Will this spread to the other tree like this I have?

I have also planted several other trees for windbreaks and shade. My soil is mostly clay, so I have to be careful about iron with the Silver maples and try to put Miracid on once or twice a year. I have also started mulching my grass clippings and putting them around the trees and rototilling the mulch into the dirt. I have a lot of ants in my yard, and I have not done much bug spraying on the trees because of the expense. Any other thoughts? (Minot, N.D., e-mail)

A: The tree sounds like the Canada Red chokecherry, and the problem sounds very much like black knot fungal disease. Cut out the branches with this growth sometime before new growth begins next spring, and spray the tree with lime-sulfur prior to leaf-out. Once infected, it is unlikely that the tree will be worth very much. You can try for a couple of years, but don't be surprised if you end up taking the tree out completely. I would suggest spraying all deciduous trees with the lime sulfur while they are still dormant prior to leaf-out. This is a very effective fungicide. Sulfur by itself, is a very effective fungicide, but adding lime to it causes a chemical change that allows the sulfur to penetrate the leaf tissue and adhere to the stems of the branches, thus killing any spores that will germinate in the near future or any that have sprouted recently.

I suggest a follow-up of Captan after leaf-out. The spray schedules must be used in coordination with a regular pruning of any of the knots that show up. Go back beyond the swollen canker about 6 to 9 inches to make the cut to be sure that any spore migration has been removed. Keeping a protective spray on the uninfected tree will be beneficial.

This disease has become rampant with this particular species--so much so that it makes it difficult to recommend it as a desirable plant to use in North Dakota landscapes.

Your action with the mulch is good--keep it up. Ants are not a problem unless they get into your dwelling. Allow them to do their thing in your yard, they make good soil aerators and mixers. It sounds like you've taken all reasonable steps to have a healthy landscape. Enjoy!


Q: I am having problems with slugs eating my tomatoes and potato bugs eating the potato leaves. Is there any way to treat the soil in the fall or spring to keep this from happening next year? (Fosston, Minn.)

A: There is a product called "Slug-Getta" that is an attractive poison. You can also get slug traps from garden centers or make them yourself. To make one, push a shallow dish into the ground and fill it with beer. The slugs will be attracted to the smell, fall in and drown. Potato bugs can be controlled by using a resistant variety, or by following a strict spray program. Clean all garden litter up this fall, turn the soil over to expose the pests and have our winter help in killing them. Also, hope for a drier summer next year. 


Q: I read an article about shredding newspaper and adding it to the compost pile. What do you think about the ink matter? How many papers use soy ink? (e-mail)

A: I advise against it. I have no idea which newspapers use soy ink and which don't. If it is a known fact about a particular newspaper, and that is the only source you use, then the shredded paper would be all right, as long as it did not make up the majority of the compost pile.


Q: Last fall in an effort to "lighten" our heavy soil we added wood chips and saw dust to my flower beds. This year many of my perennials died, and the other flowers I planted are stunted--even the  daylilies. Should I remove the soil, since sawdust ties up the nitrogen in the soil or will Miracle-Gro help? (Breckenridge, Minn.)

A: You need not remove the soil. Adding nitrogen (N) in any form will help considerably. Miracle-Gro will do, as will urea. In time, when the sawdust and chips weather, you will not need to add the additional N, and the material you added will help to condition, or as you say, "lighten" the soil.


Q: Can you tell me where I can send a soil sample to be tested from my garden? (e-mail)

A: Send the samples to: Waldron Hall, P.O. Box 5575, NDSU, Fargo, ND 58105.

Have the pH, organic matter content, N,P and K and soluble salts tested. Cost is about $20 per sample (they will send you a bill when the sample is done). Be sure to take a good representative sample.


Q: Where can I purchase lime-sulfur like you have recommended? (Maple Plain, Minn.)

A: At any major garden center or garden supply section in a major retail store.


Q: I would like to have the soil tested in my garden and flower beds. Could you please let me know where to send the soil samples and also how much I need to send? (Anamoose, N.D.)

A: I've enclosed a soil test bag from our NDSU soils lab. Request the pH, N, P, K, organic matter, and EC (Electrical Conductivity). The cost will be about $20.


Q: I have an azalea that I think needs to be repotted, but I am not sure what kind of soil to use. (Mahnomen, Minn.)

A: Yes, azaleas need a soil with a low pH, so get a potting soil specifically designated for this species. If you cannot find any, then incorporate about 50 percent milled sphagnum peat moss with your potting soil when repotting.

Expect (and hope for!) once a year flowering on an indoor azalea.


Q: Last fall I repotted some house plants in some new potting soil. Now when the soil on the top gets dry it starts to get white like the enclosed sample. Can you tell me what the problem is?

I also am wondering if I can spray my iris bed with anything this spring to control the weeds. (Tripp,  S.D.)

A: The white you are seeing is salt crystals. Nothing to worry about, unless the plants' quality starts to decline.

Once weeds get started in an iris bed, they are difficult to control. I've dug a couple up in my lifetime to get rid of weeds, and it is not fun.


Q: I think there is something wrong with the soil in my garden. The tomatoes get black spots on them, nothing grows underground, not even beets. My rhubarb wants to grow, but it has little branches that get yellow. What do I need to do to get my garden to grow? (Harvey, N.D.)

A: It sounds like your soil could stand a little work. Without knowing anything else, I'd suggest working some sphagnum peat into the top 6 inches or so. The best approach would be to have the soil tested to determine where it is from a nutrition standpoint. Once known, you can make corrective measures accurately.


Q: I've been reading your column for quite some time, and now I need your help. I purchased some new potting soil recently and I have been plagued with these enclosed tiny white flies. I have tried spraying them, but I can't seem to get rid of them. (Jamestown, N.D.)

A: Thank you for being a faithful reader! The problem is that your potting soil was not pasteurized, and the little flies, known as fungus gnats, can be quite prolific in their reproduction efforts.

Your best solution is to repot again with a better quality soil. If you can locate Scott's potting soil or something similar in quality, that should do the trick. Just be sure to rinse the roots and container completely.


Q: The soil in my flower bed seems to be really hard. I have tried to add some peat moss and fresh dirt, but to no avail. (Jamestown, N.D.)

A: You are doing right by adding peat moss and working it in. Just go one step further and mulch with either peat or bark chips. The mulch should be 2 to 4 inches thick. You will find that after one growing season the soil will have softened considerably.


Q. Someone from South Dakota wrote you about softening up their impossible soil and you told them the only practical solution was to add more organic matter and to stay away from sand, as it would turn to concrete. Well, my experience was just the opposite. I, too, had very hard soil and was told the same thing, when I ran across a chap who said that if I added enough sand, it would correct the problem. Well, it took 6 cubic yards of sand over my 450-square-foot garden to do it, but it worked! My soil is now nice and workable. (Fargo, N.D.)

A. Glad to hear it worked. It should have—6 cubic yards spread over 450 square feet covers the area about 4.3 inches deep. Work that into the soil root zone, and you have significantly changed the textural makeup of that soil, and elevated the garden as well.

Thanks for making contact and sharing the good information.


Q. I have the opportunity next spring to spread either cow or horse manure over my garden area. My neighbor tells me to use less horse manure because it is "hotter." Will it tend to burn the crops more than cow manure will? Is she right? Can you help? (Carrington, N.D.)

A. Oh, the questions I get! Yes, horse manure can have a higher burn potential than cow manure, but it DEPENDS on where and how long it has been stored. For example, if cattle manure is stored indoors or under cover before being spread, it could have a higher salt content than horse manure that has been stored outdoors. Also, it depends on the quantity of straw that is mixed with either manure, but usually cattle manure has a higher straw content.

No simple answers, right? So to be on the safe side, I recommend not applying the same amount of horse manure as cow manure, but reducing the horse manure by about 25 percent to 30 percent.


Q. Last year we had some dirt hauled in to our garden. It was to be good soil. My husband sprayed for dandelions several yards away from the garden with the hose. My seeds all germinated and looked good. Everything was several inches tall, then all of a sudden everything started dying; only the cabbage and radishes survived.

So we want to find out if it was from the dirt hauled in or from the spraying 2,4-D (just a small area was sprayed). I was sure this year I would be okay. Now I find a few nice potatoes and a few come up crippled like the one I am sending. Also am sending some soil. As some of my tomatoes and peppers are curling already, I think I will lose it all. Thank you. (Ipswich, S.D.)

A. Your soil has obviously been contaminated by herbicides, as all of the plants you mentioned--tomatoes, peppers, and potatoes--are very sensitive to phenoxy materials.

It would cost about $200 to analyze what contaminants are present and I doubt we would know much more than we do now.

All you can do is plant somewhere else or wait another year and do a bioassay with tomatoes before planting--plant a few tomato seedlings in the garden, or in soil taken from the garden, and see if they grow before planting the whole garden.


Q: I've written to you in the past about pH problems in my soil and water. You've said there was no practical way to treat the water. However, I am being given a
500 gallon water tank and propose to pump the creek water into it and treat it to make it usable for gardening purposes. My idea is to use muriatic acid, which I
now use to initially get the pH down in our hot tub. But I have some questions about the safety of using that. Do you know or can you refer me to someone who
would be able to answer some questions? (Washburn, N.D., e-mail)

A: Muriatic acid is usually sold as a salt of hydrochloric acid, in the form of potassium chloride and is used as you intend--as a fertilizer. The same material that is used in your hot tub to lower the pH would be too strong to use on plant material, unless greatly diluted.
I would suggest using sulfur-containing fertilizers. Mix in powdered sulfur and sphagnum peat moss into the soil. All of this is a lot safer and more permanent.


Q: My garden area was sprayed with Canada thistle spray in April by an airplane that was spraying the field next to it. Shortly after that I planted my garden and nothing came up and I couldn’t figure out why. Now I am convinced it was from the spray. Will I be able to grow a garden there again? (Marion, S.D.)

A: Generally, unless excessive doses of herbicide were applied, the soil should support a healthy garden next year. I would suggest removing all crop residue this fall and discing the soil. Next spring, try not to plant the crops in the same spot -- locate the potatoes where corn was, etc.


Q: I have an area that is mixed with clay and dirt. What can I do to loosen up the area? Should I add any fertilizer when I do it? (E-mail reference, Morris, Minn.)

A: The best solution to compaction is dilution with sphagnum peat moss. Work it in in the fall along with about 15 pounds of gypsum per 1000 square feet. This will improve the tilth or workability of your soil greatly.


Q: I had a call from a patron who repotted her plants using a Miracle Grow potting soil. She said the top soil on the plants is very moldy. She said she waters them every other week, so felt the problem was not overwatering. Any suggestions what she can do? (E-mail reference, Valley City, N.D.)

A: This is just a saprophyte that has found a nice home and will do no harm to the plant. She can rough up the surface and move some air across the top with a small fan if she desires. It will eventually go away, or she can scoop up the surface and dispose of it. I use the same potting soil and have no problems with it.


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