August 16, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I am enclosing two bugs, which I find in my home a few times a year. I don’t know if you identify bugs, but if you can tell me what they are or how to get rid of them, I would appreciate it. (Woonsocket, S.D.)

A: According to NDSU extension entomologist, Phil Glogoza, they are pseudo scorpions. They are not true insects, but are insect predators, holding their prey with the pinchers they have on their bodies. They are usually associated with damp places, wood piles, bark, etc. They are not harmful to humans.

Q: Is there any danger using vegetables from a garden where the weed killer "Preen" has been used? I’ve heard both ways and would like to make sure. (Oakes, N.D.)

A: It is safe as long as label directions were followed. The product has been used on vegetable gardens for years.

Q: Can you please identify the enclosed weed and tell me how to get rid of it? My neighbors lawn is just covered with this weed and it is spreading over into my lawn. (Jamestown, N.D.)

A: They are wild violets. Spray with TRIMEC now and again after Labor Day weekend.

Q: Enclosed you will find three specimens. One is from a maple tree about 10 years old. The second is from a Harolred tree. It is only 3 years old and was growing beautifully. Now there are several leaves like the one being sent to you. It sits in the middle of five apple trees, three of which are bursting with fruit. Third, the little twig with dead leaves is from a row of lilacs. This is one of three in this condition in a row of 15 around a house. It only took three days to get into this condition. We live in a very sandy soil which has had high water for the past six years, and I hope this is not the cause. (Hecla, S.D.)

A: The silver maple leaf just has some cosmetic galls on the leaves caused by mites feeding in early spring. Nothing to do or worry about. The other two samples, I am not sure. Obviously some pathogen is affecting the lilacs, and it could be downy mildew. The apple showed no pathogens on the sample, so I suspect it might be a canker or root rot problem. It is definitely not cedar-apple rust. I suggest monitoring the apple tree, and if it continues to decline, remove it. The same with the lilacs. You don’t want either remaining to act as a vector to spread to otherwise healthy plants.

Q: I need to replant my raspberries and asparagus plants. When is the best time, fall or spring, to replant and what chemical can be used as a pre-emergence? Also, I’m cleaning out a 60-year-old shelter belt and need to spray. What is safe to use? (New England, N.D.)

A: If I understand you correctly, you are asking for weed control in all instances. Casoron is registered for weed control in raspberries; Simazine can be used in many tree plantings, as well as can Casoron. For asparagus, Sinbar, Poast, and Treflan (most common) are used for weed control. Check label for rates, timing, etc., before using. Raspberries and asparagus are best replanted in early spring before new growth emerges.

Q: Enclosed are samples of green ash trees that have been sprayed with Malathion for over two years. The bugs must work at night and must be big or a lot of them, because my smaller trees are stripped. A nursery gave me some powder called "Halt" that I mix with water and spray every 28 days following with Miracle Grow and they told me to keep them watered when needed. I don’t feel it’s working, because it started with my dogwood trees. My green ash are next to them and now are getting it. I treated that row but it’s still traveling. My first dogwood has only a green stem, and this is just about where my first green ash is. It hardly has any leaves left. I put in 20 caragana trees this spring, and there is something eating them too. I sprayed them with Malathion with no luck. Could you suggest something that would kill all bugs in this yard without damaging the trees or birds? I have no children near. (Bismarck, N.D.)

A: Use a product containing Neem. It has both insecticidal and fungicidal properties and is not harmful to birds, humans or non-plant-eating insects. It is not cheap, but it is effective. One such product put out by the Schultz company, Fungicide3, controls mites, insects, and a host of fungal diseases. You are fighting a gall-forming insect that needs early season treatment. Spraying now does little good. Early next spring while the trees are still dormant, spray with lime-sulfur and dormant oil to sanitize the trees, then spray with Neem (a biological) when the leaves unfold and again in 10 days. Monitor thereafter and treat as needed.

Q: Can you please tell me what is wrong with my tomatoes. They always have enough water and I’ve raised tomatoes for years without problems. The leaves started to dry up from the bottom up and went all over the plant. I did spray with fungicide, but that didn’t help. Can you help? (Tuttle, N.D.)

A: From your description, it sounds like Septoria leaf spot. I am sending you some literature to read regarding the disease and its management. Don’t be too hard on yourself. It is normal to replant where you had good production the previous year, and this has been an ideal summer for proliferation of tomato diseases.

Q: In one of your answers to a problem you stated very emphatically that weed and feed applications are a pet peeve of yours. Will you tell me why you do not use the weed and feed products? (Carrington, N.D.)

A: For a number of reasons: Very few, if any, lawns have a weed infestation bad enough to make a blanket application of anything containing a herbicide. If the lawn is that bad, start over from scratch. The active ingredient is lower in the weed and feed than it is in the herbicide only, so weed control is not nearly as effective. Handling of the weed and feed is typically not done properly. Consumers tend to handle it like a fertilizer only, not something containing a pesticide.

Environmentally, weed and feed applications are a disaster on a small scale. Broadcast applications of herbicides are not needed in most lawn situations, just spot applications where weeds tend to be. I try to encourage people to solve weed problems in lawns through preventive good cultural practices: Mow high ( 2 ½-3 inches) with a sharp mower, alternating directions with each mowing. Maintain good, balanced soil fertility to optimize grass growth. Water properly, neither over nor under watering. Too much water on typical home lawn soils can lead to weed infestations as much as too little water. Correct compaction when needed via timely core aeration. I could say more, but I am running out of room. I believe my point has been made!

Q: I have two huge "weeping birch" trees in my yard, which I’ve had for over 30 years. Each year these pods form on the trees and these brown particles, from the pods, are everywhere. I sweep up gallons of this mess. Is there anything or any way to stop these pods from forming, and how damaging are the particles to the soil in my yard? (Regent, N.D.)

A: Be thankful you have such healthy birches! The "pods" are male catkins which are necessary for fertilization of the female (pistillate) flowers. I assure you they are causing no harm to anything on your property and will eventually decompose on their own. Spend your time doing something that you enjoy and don’t worry about your trees. They are fine!

Q: We have a Japanese Sumac in our yard that is approximately 19 years old. The tree has never been a problem but this year it seems to be dying off. The leaves are wilting as if the branches have been broken but they are not. The seed clusters have not developed well this year and are soft with most of the seeds falling off already. The old tree has never been affected by cool, hot wet or dry summers. There does seem to be more brown spots on the new growth than usual, and a bluish tint on the trunk. We did find a 2 inch "sore" on one trunk. Could you please help. (E-mail reference, London, Ontario, Canada)

A: Unfortunately from your description, it sounds like your sumac is suffering a death from Verticillium wilt, a soil-borne fungus that affects the vascular system of the plants it attacks, essentially killing it off. This is a progressive, terminal disease. You have a university in Guelph, Ontario with a good horticulture program and, I am sure, an equally good diagnostic lab. Try contacting them to see if they can perform a diagnosis for you. If it is something else that I am missing from your description, maybe the condition can be halted. I would like to be wrong in this case!

Q: Our linden tree was planted two years ago. It is approximately 10 feet tall and doing rather well except that it has developed vertical cracks in its trunk. There are several, all on one side and running up about 10 inches, some of which are 1/4 to 3/8 inches wide. It is as though the tree had a growth spurt and the trunk couldn't keep up with it. I'm concerned that this might encourage borers. Is this normal for this tree, and what if anything should be done? (E-mail reference)

A: Splitting like that is not normal. I assume you purchased the tree locally. Since I don't know where you live, this is important, as there are differences in trees coming from different parts of the country that can affect their hardiness. There is nothing to be done except to wait for it to heal naturally over the ensuing years. As autumn approaches, wrap the tree to protect it from further sunscald damage, and avoid pruning any lower branches for at least the next two to three years, to provide shade protection on the trunk. Lindens are pretty tough. I don't think you have anything to worry about.

Q: I have a shelterbelt on my farmstead that was planted in 1989. This year I have been losing the Robusta poplar trees. Approximately 15 are dead or appear to be dying. At first there were a couple that didn't leaf out. Now it appears to be moving on to others in the row. Some are bordering each other and some not. I examined them and see no noticeable insects or leaves with insect damage. Please let me know what you think it may be. (Forman, N.D.)

A: As for poplars and their problems, take your pick! There is an entire book dedicated to poplar trees and their problems. Stem cankers, leaf spot fungi, root rots, etc. Probably the only way to determine what is happening is to have our diagnostic lab to do some tissue sampling. Otherwise, just write them off as a loss.

Q: I was searching for information on cattails and saw questions directed to you on getting rid of them. I have the opposite problem. I want very much for them to be part of our landscape but haven't had luck transplanting mature plants from ditches. How can I grow them on my property along a storm sewer wash that flows regularly with rain water and gets four to six hours of midmorning to midafternoon sun? (E-mail reference)

A: I don't know what to tell you, so I'll try to depend on readers to tell me, and I can pass it on to you. Just be patient. It may take several weeks.

Q: We have a large (18-inch) beautiful lichen growing on a dead tree stump which has been cut off at the ground. It is creamy white in the shape of a rose. We would like to know the best way to remove and preserve this specimen. (E-mail reference, LaMoure, N.D.)

A: I stand to be corrected, but I think the best way to do that is to cut if off as a slab of wood, with the lichen intact, of course.

Q: I have a wonderful large and frequently blooming lipstick plant. My husband just told me about a very similar looking plant called a goldfish plant. I can find very little information about it. (E-mail reference, Chicago, Ill.)

A: This is a common name that is broadly understood to mean Columnea banksii, which is an easy form of this species to grow. They have a list of demands that must be met in order for them to perform satisfactorily. Among them are frequent misting to keep the atmosphere moist around the foliage, compost on the dry side during the winter months, and night time temperatures between 55 and 65 degrees F. If you overwater, botrytis will be a problem. Fertilize at regular intervals in spring and summer, trimming back foliage once flowering is over.

Q: Last year we planted 50 Redcoat strawberry plants in our home garden. Last summer a few leaves began turning yellowish green with streaks of yellow in them. Much more of the same this year on the mother plants and runners. We did harvest a nice crop of berries. A local gardener mentioned possible iron deficiency in this area. If this is the case, how do I correct it? Also, where do I send a leaf sample for a more exact diagnosis? In the ‘80s we had a 2-acre U-Pick strawberry business near Jamestown. At this time of the year we fertilized with 10-10-10 fertilizer. That particular ratio seems hard to come by in small quantities. What else could we use? ( Gilby, N.D.)

A: If the new growth had a general, over-all yellowing with the veins remaining green, it could be iron shortage. If the yellowing is streaked, it could be a virus-type pathogen. If the yellowing is overall, especially with the older leaves, and the new growth green but limited and undersized, it could be nitrogen shortage. Send a sample to the Plant Diagnostic Center, Waldron Hall, NDSU, Fargo, 58105 for a more accurate analysis. There will be a nominal charge depending on what tests have to be run. If you cannot find 10-10-10, look for 12-12-12, or anything where the analysis is the same for each of the nutrients. The only difference is the amount applied with the higher formulations.

Q: Can you tell me if black cherry fruit is okay to eat? (Ellendale, N.D.)

A: Black cherry fruit is edible. Just don't eat the pits, branches, or leaves on this or any other Prunus species. And, like many of the others, it does make good jelly and wine.

Q: I just purchased a wonderful Lace Cap hydrangea. My question, is can I keep this amazing shrub alive in a container to enjoy at work with me? I live in Las Vegas, Nev. and do not want to subject this wonderful plant to such an environment. I would love be able to enjoy it's beauty at work with me, but do not know if it will survive as an indoor container plant. (E-mail reference, Las Vegas, Nev.)

A: Lace Cap is a cultivar name of the species that is typically used as containerized plants for indoor settings. This plant has two basic needs: cool conditions (ideal in a air conditioned environment) and to not let the soil dry out between waterings. Once the flowering has passed, cut the stems back to half their original height. After flowering, repot and continue to water and fertilize. In your hot location, keep indoors in summer and move outdoors on frost-free days in winter. Somewhere in between there will likely be a need for a rest period. When the plant starts to fade, cut back on the watering for a period of about six weeks, then begin the cycle again, keeping it in bright light but never direct sunlight.

Q: A tree in our lawn has been there at least 30 years. I believe it is a silver maple, but it could be sugar maple (we're not experts). There are several problems. First, it is "weeping" or bleeding at several places. In some places it appears to be sticky to the touch, but where it pools, it is like a muddy dampness. Second, the lowest branch has become hollowed, just sort of dying away inside while the leaves seem healthy and green. Overall the growth and color of the leaves appears normal and healthy, but some of the leaves are falling early with a yellow-green appearance. Before we call a tree surgeon, any suggestions? (E-mail reference)

A: I suggest a tree surgeon come out and take an increment boring of the tree. This will determine the soundness of the trunk and whether or not it is a potential threat for windfall in a storm. In some cases, the tree does not need to be removed; in others, it is best removed immediately. A competent, ethical tree surgeon will advise you properly. Just don't delay having it checked for safety's sake.

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