May 31, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I bought two peonies for my mother on Mother's Day last year. We planted them promptly. I thought planting them that early would cause a problem, but it didn't. However, this year, about the same time, one was about to bloom, the other had not produced even a hint of budding. Both are very healthy plants, planted in partial sun, great condition soil...no signs of pests, fungus or disease. The other plant is budding like crazy and they are planted no more than 4 feet apart. Why is one blooming and the other not? (E-mail reference)

A: The one plant is probably not flowering because it is planted too deep. Carefully check to see that the crown where the "eyes" of the plant emerge from is no more than 1.5 to 2 inches below the surrounding grade. If that is the case, pull the soil covering the crown back to that depth. The plant will not suddenly flower this year but should do so next season.

Q: I spotted a good-looking, reasonable-priced apple tree this spring. The variety is "State Fair" and it is a dwarf tree, according to the tag. I am not able to locate any information on this variety for North Dakota. Is it not recommended here? (Carrington, N.D.)

A: The State Fair apple is recommended for trial purposes across North Dakota. I would encourage you to give it a try as it is an excellent apple, with the best storage qualities known in our area. Apples can keep until May. I am planning to plant one in my back yard this spring.

Q: How can I get information on rununculas? (E-mail reference)

A: Ranunculus asiaticus, or Persian buttercup, is hardy in zones 8 to 10; elsewhere grow it in pots. Plant in damp, light, well-drained, compost-rich soil in the autumn, or until the soil freezes. Bulbs will rot if planted in hot weather. Grow in full sun, keep cool at night. Flowers come on in early spring in a variety of bright colors - from red to white, with orange and pink in between. Some are single flowers, but most are bred now for double or semi-double flower show.

Q: I have a youth group that is going to plant a "pumpkin patch." I need some variety recommendations so they will have a variety of sizes. (E-mail reference, Ashley, N.D.)

A: Here are some varieties to consider: Baby Bear (1-3 pound pumpkins), Autumn Gold (10-15 pounds), Baby Boo (6 ounce fruits - white), Jack Be Little (3-6 ounce fruits), Connecticut Field (15-25 pounds), Small Sugar (4-10 pounds - good pies!) And Lumina (10-20 pounds).

Q: During clean up there will be lots of old wood and brush to be burned. Since most of the minerals will remain in the ashes, can it be used for fertilizer, and how? Seems to me we used to make soap by pouring water thru wood ashes for the "lye" component, so I imagine ashes would tend to make the ground highly alkaline. (Bismarck, N.D.)

A: Yes, ashes can be used as a "fertilizer," and yes, they are very alkaline. I would suggest mixing just a little into the upper part of the soil--1 inch covering into 4 inches of soil--and see what results you get. If your soil is already quite alkaline, you will likely not notice any difference.

Q: I have a road ditch that is too steep to mow. What would be a good ground cover to plant to choke out the weeds and grass and not need mowing? ( Hillsboro, N.D.)

A: You ask for a lot, and I don't think I have the answer. Crown vetch needs mowing at about 6 inches to keep it looking decent, any grasses would need mowing, wooly speedwell needs perfect drainage, prostrate junipers would cover, but grass would still grow through it. I'm going to put your question to the reading public and see if someone else has had a similar problem and has come up with a satisfactory answer. Any that I get, I'll relay back to you.

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: My apricots, pears, cherries, plums, apples, and grapes are blooming. What happened? Five different pears are blooming, one tree has 83 clusters of flowers, with five or six to a cluster. I wish I had some bees. Do I need to worry? ( Grand Forks, N.D.)

A: Spring came--suddenly! Don't worry, you'll get your fair share of fruit set.

Q: I have anthills showing up in my back yard. What can I use on them? The only problem I have about using poison is that I have an 11-month old puppy and two small children that play in the yard. (E-mail reference)

A: Try grits. I read somewhere that they will take those in as food, eat them, and because of the expansion that takes place in their gut, the ants die. It won't happen overnight like a poison will, but is supposed to work to get rid of them. Give it a try and report back to me. Simply sprinkle it around the mounds you see them making.

Q: How do I get grass out of my perennials? I also have a cactus in there that I want to keep. I pull the grass each year but it always comes back. ( Amidon, N.D.)

A: The most universal herbicide to use in such plantings is Surflan. It will take care of grassy and many broadleafed weeds. The plot needs to be clean cultivated first.

Q: I just planted two silver maples about 30 feet from my house in the backyard. Some neighbors told me that was ignorant, as silver maples have such a bad reputation. I was hoping for a showy yellow color in the fall. However, should I dig them up and plant red maples instead....or something else? (E-mail reference, Indianapolis, Ind.)

A: If you got seedling silver maples, they may be right. If you planted named cultivars like McKay's Seedless or Silver Queen, you'll probably get the dependable fall color you are looking for. If you just planted the seedlings and not the named cultivars, and the fall color is important to you, AND you want to please your neighbors, then take them out and select one of the many cultivars of red maple. Everybody will be happier then.

Q: My father has several plum and apple trees that produce abundant fruit, but most are infected with insects that make most of the fruit inedible. In the past he has tried various products, such as the sticky residues, with very little success. He has purchased "Oil-Away," which is 94 percent cottonseed oil. Several of his garden magazines recommend spraying the trees with this product or another called "Eco-Oil". Do you have any experience with this or similar oil products? When is the correct time to spray and how many times would it be necessary to control the various fruit insects, such as apple flies and aphids? (Bismarck, N.D.)

A: Eco-oil is another name for a vegetable based oil that can be used when trees and shrubs are in full leaf. If your dad wants worm-free fruit, he will have to employ a number of tactics:

Good sanitation--picking up fallen fruit every year; pruning out excessive twigs and branches, and any that are broken or diseased. 

Pheromone traps--these are sex attractants that pull the males into the trap, preventing them from mating with the females, which then cannot bear young or lay viable eggs. 

Spray program--use Sevin at blossom time, after blossom drop, and again about 10 days later. Once he breaks the cycle of infestation, he can then employ organic methods such as the sticky trap, pheromone traps, dormant oil sprays, sanitation, etc., to effect control.

Q: I have a large strawberry patch. Unfortunately, the quackgrass has overtaken a portion of it. I would like to rid the area of the pesky grass but found it to be extremely time consuming to dig up each plant and pick the grass out of it. Is there anything that I can do to rid the patch of the grass that would be less time consuming? Also, any suggestions on how to rid my garden of very hungry squirrels? (E-mail reference)

A: Poast (sethoxydim), Fusilade (fluazifop-P-butyl) and Prism (clethodim) are the herbicides for grass control in strawberries, and only Poast is labeled for strawberries that are bearing. Be sure to follow label directions to get effective control. Squirrels are tough little customers to control in a garden. Exclusion fencing in the form of rabbit wire, "caged" over the plants of choice for the squirrel seems to work best for us. Also, it helps if you have a feeding station away from the garden for them to "discover."

Q: We are noticing a lot of dead turf areas along our city streets this year, even on the older established grass areas. We have not changed any of our mixtures of salt and sand for winter use. Any ideas on what might be going on? Environmental? Moisture? ( Fargo, N.D.)

A: Could be a combination of all that you mentioned. I suggest getting a quick soluble salt test taken on some of the dead spots. Remember that we had a very wet year last fall, then snow on top of unfrozen soil. The snow piles up on that part of the turf, and can kill it quite easily under those conditions. I suggest overseeding with a boulevard mix that is a good tough one and tolerates salt compaction, drought, etc.

Q: What causes yellow spotting on the leaves of my rhubarb?

A: Phytophthora root rot is the most common disease of rhubarb, attacking the plant crown, causing the stalks to rot at their base. It is characteristic of poorly drained soil. If it is just a stalk or two, I suggest cutting it off, and using the stem in cooking. If it reappears throughout the season, then send in a leaf to my attention.

Q: My 90-year-old mother has a tea rose that bloomed fine for years but last year did not offer one single flower. It is incredibly healthy in cane and leaf. It sits along side of 10 other tea roses, all of which bloomed great last year. It has full sun, no disease or insects and no sucker root problem. She wants to dig it out, but I said after going through all my resources first, that I would then write the master. And that would be you. (Bismarck, N.D.)

A: That is a weighty title you thrust upon me! I'm not sure I want it, as I am always learning something new as well. The only thing I can think of is the possibility of borers entering the cane cut ends last year after they were pruned back in the spring. They may have caused enough damage to keep them from flowering but not from producing vegetative growth. Ask her to inspect some of the canes on that rose plant, cutting back to see if the center was hollowed out by borer activity. If it was, she should cut back to where the canes are solid and light colored. I would then suggest sealing those cut surfaces with clear fingernail polish to help prevent the borers from entering again. If that isn't it, then I am at a loss.

 

Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu