NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
October 21, 1999
Ron Smith, Extension Horticulturist
North Dakota State University
Common Horticulture Questions Before Winter Arrives
(Note from Ron Smith: The first three questions seem to come from all directions this time of year, so I've decided to provided my answers en masse to the masses.)
Q. How late can trees and shrubs be planted?
A. Fall is an excellent time to get most of this planting done, as the growth activity is confined to below ground in the root system, giving most plants a good head start during the subsequent spring.
The planting can be done anytime in late August, September or October, as long as the ground has not yet frozen. Keep in mind that as the soil/water temperature gets below 40 F water moves with greater difficulty into the roots, thus slowing down the whole growth cycle.
Woody plants are sold as bare-root (BR), balled and burlaped (B&B), or container grown (CG). BR plants offer the advantages of being less expensive and easier to handle and having no soil interface problem that sometimes occurs with the other two. B&B plants have the nursery soil within a burlap ball, and generally about two-thirds to three-quarters of the original root system. Beware of "wild-dug" or shelterbelt-dug trees, as they would have no more than 5 to 10 percent of the root system remaining. CG plants have literally all of the root system present when planted (after the container is removed, of course).
Some people like to use live spruce or pine trees for the Christmas season. With a little advanced planning, this is possible. Simply mulch the area thickly with straw where the plant is intended to go after the holidays, and it will stay unfrozen until planting after the season.
With any of these plantings, be sure to water in completely.
Q. How often should mulch be replenished?
A. Whatever it takes to maintain a 2- to 3-inch layer of mulch, with fall being an ideal time to check and replenish as needed. Be sure to be consistent in the use of the mulch material to avoid a layering effect--if you start out with bark, stay with it--don't change to compost, unless your are up to removing the bark first. Be sure to rake the existing layer of mulch before adding the new material. And be sure the mulch is kept away from the trunk of trees so that it does not encourage disease or rodent activity to develop.
Q. What can I do to protect my trees from winter injury?
A. If your area of the state has been dry, then the first step toward protection is to make sure of ample moisture in the root zone. Plants can then build reserves in their tissue that will help them resist the vagaries of our winter weather. Wrapping trunks of thin-barked trees with tree wrap up to the first branch will help to reduce sunscald. Remember to remove it prior to new growth beginning next spring.
Any evergreens with a historical record of winter burn should be protected with a barrier of burlap on the south, west or windward sides to block the sun and wind. The application of anti-desiccant sprays is especially helpful as well. Research has shown that these sprays are most protective when applied during late winter thaws (February-March) than at this time of year. This is because the sunlight intensity is increasing, causing the evergreen needles to lose moisture that cannot be replaced because of the frozen branches or soil.
Rodent damage from voles and rabbits is a reality in our part of the country. To protect vulnerable trees, enclose the trunk with a cylinder of quarter-inch hardware cloth or white drain pipe. Here's the trick: get the cylinder to go above the snow level to be effective--an impossible task during some winters.
Other means of protecting can come from repellent sprays which must be re-applied, and all vary in effectiveness. I have found it easier to simply make other food available for them, such as cracked corn and sunflower seeds. They seem to prefer that to the bark of my trees and shrubs.
Q: What is Trimec? A brand name, or ingredient, liquid spray or granular product? I can't seem to find it in my local stores. (Wagner, S.D., e-mail)
A: Trimec is a proprietary product of the PBI Gordon Company, which has a Web site at www.pbigordon.com where you can click on the Turf and Ornamentals section and get all the information you want on Trimec formulations. Basically Trimec is a broadleaf, postemergent weed killer that can be used selectively in turfgrass situations. They may be able to tell you where a local supplier is in your area.
Q: We have a plum tree that has six main branches; three lost their leaves early and now those branches are weeping, the other branches still have leaves. Any ideas? (e-mail)
A: The plum tree branches could be suffering from either borer damage, with the "weeping" coming from the holes created by the borer activity, or it could be coming from a canker that has developed on the branches. Check on the weeping branches to see if the material is coming out from small holes about the size of pencil lead, or from oozing wounds caused by the fungal canker. In either case, you are likely to lose the tree and are better off to have it removed either this winter or early next spring.
Q: I am doing everything wrong with my strawberries and they won't quit bearing. I bought 25 Everbearing plants from Guerneys more than 15 years ago and planted them in two rows that were 6 feet apart. The patch is now at least 25 feet long and about 13 feet wide--solid. Right now I have nine gallons in the freezer from this year alone. I don't do anything special to keep them growing, no fertilizer or anything.
I also have a coleus in my house that is 20 years, alive and very healthy. I don't enjoy gardening, but I have trouble killing a plant if I don't like it, except to throw it away. I also planted six pansy plants in June, and I now have a solid bed of them. (Regent, N.D., e-mail)
A: Congratulations on having a green thumb, good luck, good location, and a perfect environment for growing that particular cultivar of strawberry! If you were closer, I would raid your patch!
You have a coleus that is 20 years old? Send that in to the Guinness Book of Records--it simply has to be a record. Most people are happy to get them to last one growing season. You must have an amazing ability that you don't recognize in handling plants to get them to last that long.
Q: At what time of the year does one trim global arborvitae? Should Potentilla be cut back and when? Does one cut back Clematis in the fall, spring or not at all? (Grenville, S.D.)
A: The best time to trim your arborvitae is in the spring when active growth can take place. Cut the potentilla back in early spring prior to leaf-out. Most clematis varieties bloom on new growth produced in the spring. Cut back in early spring to about 6 inches of old growth remaining.
Q: We have chokecherry trees in our yard and the birds keep taking all of the fruit. How can we stop them? Will they ripen if I pick them green and put them in the patio? (Milnor, N.D.)
A: No, the berries will not ripen that way. Try netting or scare balloons, or both. Sometimes birds can be encouraged away easily and other times not. I've received good reports on these two items doing the job.
Q: Is there a product we can use on our lawn to get rid of mushrooms? This summer we've even had mushrooms in the sunniest, driest part of our yard!
Also, I have a flower bed next to the foundation on the south side of our house. Three sides of the bed are surrounded by a small brick/cement wall so the entire bed is enclosed in cement. For the last eight summers we have tried to grow a variety of flowers and/or shrubs in this bed with absolutely no luck. We've replaced some of the dirt and added mulch and compost but whatever we plant dies. Any suggestions? (Jamestown, N.D.)
A: First, there is no known chemical product that can be applied to control mushrooms. They will eventually decrease and disappear.
And second, my best guess is that the plants are being killed off by extreme heat buildup. If there is no free drainage, that too could be a problem! Try planting some heat-loving plants such as potentilla, vinca, and portulaca. If those plants die, then it is something else that is doing them in. Do you get any weed growth? If not, then a toxic residue is there and all soil needs removing.
Q: I have noticed orange looking spots in my lawn this fall. Please let me know what is wrong and what I should do to treat it. I have tried to trim most of it off. I hope that helped. (Oakes, N.D.)
A: You've got a perfect example of the rust fungus! It shows up on some species of grass and not others. It is almost always nonlethal to home lawns. You did the right thing--cutting off the diseased grass and disposing of it. While there are chemicals you can apply that would help control this disease, I don't encourage it. The grass usually outgrows it, or the environmental conditions change over a short time period and the visible symptoms disappear. Just continue to follow good maintenance: mow regularly, fertilize a couple of times each year and water when needed.
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 firstname.lastname@example.org.
Source: Ron Smith (701) 231-8161
Editor: Dean Hulse (701) 231-6136