August 9, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have enclosed a sample of redwood bedding that I would like to put down in my flower bed. Is it okay to use? Also, I have a mango and I understand that the inside pit can be planted. What do I need to do with the pit to get it to grow? (Carrington, N.D.)

A: Yes, the bedding looks great! Use it. The mango pit needs to be planted in a 4-inch pot, burying the pointed end and leaving the last one-fourth of it exposed. Keep at room temperature and keep moist. Growth should be noted in four to six weeks or sooner.

Q: I have an "angel’s blush" Morovian hydrangea. The leaves are turning brown and crisp around the edges. I have given it Mir-acid, and it is planted on the north side of my house. What can I do to get rid of this problem? I am enclosing a couple of leaves for you to look at. (Portland, N.D.)

A: It appears to be salt burn, drought stress, or soil compaction symptoms. In other words, an environmental stress rather than a pathogen. Try laying off the fertilizer and leaching with water to see if it improves.

Q: My grass is turning brown in this hot, dry weather. Is it dying? (Fargo, N.D.)

A: No, unless it goes a whole month without water. Cool season grasses, which most home lawns are, tend to go dormant during extended periods of hot, rainless weather.

Q: Enclosed is a sample of a weed that is taking over my newly planted lawn. (Bowdon, N.D.)

A: The weed is a beautiful sample of purslane, which is an annual, producing over 52,000 seeds per plant. If you can wait, the frost will kill it, but you likely don’t want to wait that long! So, I’d suggest using a formulation of 2,4-D to control.

Q: I am enclosing a sample of a clover-like plant with small yellow flowers. Can you identify it for us? Also, we have a lot of ground in our yard that has quite a bit of alkali. What perennial flowers or trees/shrubs survive in that kind of soil? (Jamestown, N.D.)

A: You have black medic taking over. TRIMEC is the only selective herbicide that will take it out, but it will require repeat applications. Xeric-rated plants will usually do well under alkaline conditions, and the list is too extensive to include here. Some reference suggestions obtainable through your local bookstore: "Xeric Gardening" by Ellefson, Stephens and Welch, Macmillian Publishing, ISBN#0-02-614125-6; "Xeriscape Plant Guide" by Denver Water American Water Work Associatin, Fulcrum Publishing, ISBN#1-55591-322-9; "Creating the Prairie Xeriscape" by Sara Williams, University Extension Press, University of Saskatchewan, ISBN#0-88880-357-5. You can expect lists containing nature’s toughest: daylilies, sumac, Achillea, etc. All three are excellent books. Any one of them will answer your questions.

Q: A year ago I planted two rose bushes. I pruned the roots some and placed the rose roots in the ground. The roots are growing, but it’s just one long stem over 8 feet high. Will it get to be more bush-like and flower? Will it end up looking like the "silent moment" roses that I originally planted? (Park River, N.D.)

A: You’re growing a rose bush from the root of a different species than the one you bought. Roses are grafted on to rootstock to impart vigor to the scion or budwood. Your testimony about its rate of growth is proof of that vigor. The flower will (if it comes at all) not look like the "silent moment" rose. I suggest digging out this rootstock and disposing of it. If you want to try to grow this rose, take cuttings from the stem.

Q: I used to have good luck growing pansies in a pot, but for the past four years they have started turning yellow and the buds have dried up. I don’t see any aphids on them. I have sprayed, which hasn’t helped. I noticed a friend’s pansies were also turning yellow. What can be wrong and what can I do in future years to prevent this? (Fargo, N.D.)

A: Perhaps you are expecting too much from them. They do best in the cool weather of spring and fall. Recent hot weather, especially when the plants are grown in containers, could be the cause of their decline. Otherwise, I suggest going for enriching the soil with sphagnum peat moss. Our plantings in Williston and Dickinson still look good at least in part because of that treatment.

Q: I have a 3-year-old red twig dogwood tree that has never grown more than 14 feet tall. It starts growing from the ground each year in the spring. How can I get it to grow taller so it will bloom? Also, I planted a Redbud, a weeping willow, and a Ben Franklin tree this year. How can I protect them from the winter frost? Do they need to be protected? (Onida, S.D.)

A: The dogwood doesn’t like where it is planted. Replant it somewhere else. It never hurts to give fresh plantings protection through the first few winters. Wrap the trunks and make sure they go into winter well hydrated.

Q: I’m sending along two samples of weeds in my lawn. I have used Weed-B-Gone on my lawn to get rid of these weeds, but the weeds keep coming back. What else could I use to get these weeds out of my lawn? (Valley City, N.D.)

A: It appears that the weed you are fighting is common yarrow--a tough one to control! This calls for TRIMEC. Apply now and again after Labor Day, and that should take care of it.

Q: When my tomatoes start blooming before the plant is well developed and bushed out, I pull the blossoms off to give the plants a chance to bush out more. My neighbor says if I do this I will have no tomatoes. Which one of us is right? (Audubon, Minn.)

A: I vote for your neighbor. I know many Master Gardeners and commercial growers of tomatoes who never follow that practice. They consider every bloom a potential tomato fruit!

Q: I have a red maple that I planted three years ago. It developed a large cut in deep enough to see the core of the trunk. I wrapped the gash and weeks later a similar yet different shaped cut appeared above the wrap. This one is only about 1/2" wide and swirls around the tree for approximately 6 inches. The rest of the tree appears very healthy. There's tons of new growth this summer. Am I infested? What am I to do? (E-mail reference)

A: Red maple trees are notoriously thin-skinned in their early years. I would suggest a full trunk wrap until some corky tissue begins to develop. Also, resist any unnecessary pruning, as this often exposes new trunk tissue to sunscald problems. Eventually, everything should heal as the tree matures. Simply keep it growing vigorously.

Q: I have a lady who says she has raised sweet corn all her life and has never had this problem. The corn in her garden has tiny black flies on the tassels. I thought it was just a fly that was attracted to the tassels and would do no harm. (Steele, N.D.)

A: They are likely confused chinch bugs that should be feeding on the leaves but perhaps find the silk more tasty. If they are truly flies, then I think they are going after the "nectar" on the silk and are nothing to worry about.

Q: Lawn care companies’ big promotion is four applications of weed control and fertilizer throughout the spring, summer and into fall. I would like your opinion on these multiple treatments. Also, what would be some questions the homeowner should ask the company regarding, the amount of herbicide and fertilizer that should be applied during the four shot treatment? Does it do any good? What should the homeowner know or ask to get the best return on investment? (Bismarck, N.D.)

A: Good questions! In fact, I just published an article on the very subject, so I guess that makes me an "expert!" The applications are usually of both pre-emergence and post-emergence herbicides combined with fertilizer, which can either be a straight nitrogen or a "complete" fertilizer containing nitrogen, phosphorus and potassium (N, P and K). The pre-emergence herbicide is applied first, early in the season to control any weed seed germination. Subsequent applications are usually of post-emergence herbicides that should be spot applied as weeds become noted in the turfgrass and are usually for broadleafed weeds like dandelion, thistle, plantain, etc. If broadleaf herbicides are applied in a blanket fashion and not selectively, there is a potential for problems with woody ornamentals, depending on what they are using for the herbicide. As far as the fertilizer goes, the applications are usually light enough to not burn or over-stimulate the turf but to keep it growing in a steady, healthy manner. Kind of like eating several small meals throughout the day, rather than pigging out on a Sunday morning brunch.

Questions to ask a potential lawn care service provider include: length of time in business; training in handling of pesticides and fertilizers; are their broadleaf herbicide applications selectively applied to only where the weed(s) exist or is a blanket application made over the entire lawn; can they provide an organic service, and a list of reference clientele. A good lawn care service provider will have many lawns to refer you to and will proudly do so. As far as doing good goes, research has shown that homeowners bungle the task way more often than any service company personnel do. They over-apply fertilizer and pesticides, often using "revenge" spraying to "get those #@!&!! weeds" and as a result compromise the quality of their home environment and possibly their community. Lawn care service providers daily make up mixes and calculate square feet for accurate application. The homeowner is on a learning curve every time he tries it, getting it right sometimes, blowing it most of the time. In most cases a lawn care service is a good investment

Q: A local homeowner read in your column that you can spray Poast in strawberries to control quackgrass. She was wondering if she could also spray Poast in her perennial flower garden to kill grasses. I looked at the label, it did not list perennials. If not, is there anything else she could spray, or other way to control quackgrass? (Steele, N.D.)

A: Quackgrass is the ultimate challenge in gardening! If someone could come up with an "over-the-top" spray of a mixed bed of perennials and woody plants that would selectively take out the quack, that person would make millions. Vantage has the same active ingredient as Poast, is more reasonably packaged, and bedding plants are also on the label. It is labeled for quackgrass.

Q: We have two hardy hibiscus plant that were planted this spring in north central Kansas, have grown and are blooming, but the leaves are curling both upward and downward right from the beginning of the growth. Some of the buds also drop off before blooming. We feed them miracle grow monthly and water as needed. Do you have any suggestions? (E-mail reference, Kansas)

A: Hibiscus are somewhat temperamental and are not on my list of favorite plants. Although they are touted as pH adaptable, it could be the high pH of your soil that is causing the leaf curl; possibly the hot, dry, Kansas air is causing bud drop. Try adding sphagnum peat moss to the soil to sustain an even moisture regime and depress the pH somewhat; try spray misting the buds to see if that reduces bud drop. Where these plants thrive, they can look great! Also, remember to prune hard next spring to encourage large blooms and fresh growth.

Q: I am wondering if you can give me any information about North Dakota wild prairie roses. I am especially wondering if they can be transplanted from the roadside to a more conventional type of garden. I am very fond of them but have had little success when I have attempted to transplant them and wondered if perhaps you could shed some light on the subject. ( Wishek, N.D.)

A: Your lack of success is likely tied with your timing in moving them. I suggest picking out the ones you want to move a full growing season ahead, tag them, root prune them, then dig them the following spring while they are still dormant, pruning them back by about one-third before doing so. Set them at the same depth, water and fertilize, and you should be successful.

Q: I am interested in starting a few plum trees. My friend has some lovely trees and I would like to take some starts from her tree, but I don't really know how to do it successfully. Any and all help that you can give me will be gratefully accepted. (E-mail reference)

A: You apparently are one who likes challenges. Rooting cuttings is out, as researchers have only had a 7 percent success rate under ideal conditions, so seed is the only way to go. Take seed (remove the pulp) and plant it where you want the trees to grow this fall. I suggest planting several seed to assure something coming up the following spring. First, place the seed in the crisper of your refrigerator in contact with moistened sphagnum peat moss for about 90 days. This is known as stratification. Check periodically to see if the seed has begun to split and the radicle (embryonic root) has begun emergence. If so, plant immediately. But either way, plant before freeze-up this fall. Stratifying it in the coolness of your icebox prior to planting may save you a whole year, otherwise, it has been known to take up to two years for germination to take place when directly sown outdoors without the cold stratification.

Q: I am spraying potatoes with Sevin but do not seem to be getting the job done. Do you have a better suggestion? (E-mail reference)

A: Try Neem, by Schultz or any other company marketing this product. It is a botanical that is not harmful to beneficial insects. Most likely the beetle has built resistance to the insecticide Sevin.

Q: I have a houseplant that I thought was called a shamrock. It has three triangular shaped leaves and gets small white flowers. It grows from small pinecone looking bulbs. Lately, the leaves have been turning brown from the tips. I have looked for bugs but can't find anything. I did put them outside early this spring and thought the frost might have gotten them, but the new growth is still doing the same thing. Can you help me with the name of the plant and what is wrong with it? (E-mail reference)

A: Shamrock is a term given to clovers, the three-leaf and four-leaf ("lucky") types. The plant grows by runners, and I suspect that is what is turning brown. If you can peg or keep the tips in contact with the soil and keep the soil moist, they should root and not brown up on you. "Shamrocks" need regular fertilization too; once a month with a houseplant material. Shamrocks have been considered by the Irish as good-luck symbols since earliest times, with the superstition persisting today whether one is Irish or not. Officially, the shamrock has been identified by the US Department of Agriculture as Trifolium repens, or white clover.

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