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Ron Smith answers questions about flowers, trees, gardens and shrubs.

By Ron Smith, Horticulturist

NDSU Extension Service

Q: I have a mosquito geranium that I bring in every fall, but this year my space is limited. Can I overwinter it the same as a regular geranium or does it need to be watered and in sunlight to survive? (e-mail reference)

A: You can overwinter it as you would a regular geranium, but you will have the same associated risks of the plant not surviving. Another option is setting it in a window on the south or west side of the house to give the plant a little extra light energy. Also, keep it watered to increase the plant’s chances of survival. The choice is yours.

Q: During a massive storm, a huge branch broke off my silver maple tree. It left a 7-foot section on the side of the tree exposed, but the trunk does not look rotten. However, it looks like bark was growing between the branch and the trunk. Can I do anything to save the tree or should I be saving money to have it removed? (e-mail reference)

A: There is some good news with this incident in that your tree appears to have a solid core. What you described is called “included bark.” This means the bark is squeezed between the branch and trunk due to the tight V shape angle of the branch attachment. This makes for a weak connection, as you discovered. I would encourage you to locate an International Society of Arboriculture certified arborist in your area to clean up the wound as soon as possible or before spring growth begins. Being an otherwise healthy tree, it will begin the process of wound closure with new growth. The growth will continue every year until the wound is closed. To find a qualified arborist in your area, go to

Q: Late this summer, we noticed a couple of our tall ponderosa pines had an unusual faded color and seemed to be losing needles more than normal. One tree looks like it may be dead. We had a man from the Natural Resources Conservation Service look at them to diagnose the problem. He said the trees had needle blight. He also said the trees needed to be sprayed three times next spring and summer. Is needle blight a fungus that might be killed by the cold temperatures this winter? If that happens, will I have to spray at all next year? If I do have to spray, do all of the trees have to be sprayed or just the ones looking poorly? These trees are in two shelterbelts on both sides of our home, so there would be hundreds of trees to be sprayed. Does this fungus spread from tree to tree or will an infected tree not influence the one next to it? Other than hiring a helicopter, how can I get these trees sprayed when they are so very tall? These tall pines are the highlight of our farm, so we do not want to lose them. I also am wondering what the bill might be if we have to spray that many trees. If this is a killing fungus, I would think the Black Hills would get it at some point and would wipe out all the pines. (Highmore, S.D.)

A: This is a serious fungus disease that needs to be controlled with regular copper-based sprays. These would include fungicides such as Liquid Copper, Tenn-Cop 5E, a bordeaux mixture, fixed coppers, copper sulfate Mancozeb, Dithane T/O Chlorothalonil, Daconil Ultrex and Bravo 500. How to schedule applications can be found on the University of Nebraska website at As for methods of application, I would encourage you to contact John Ball, South Dakota State University forester, to get some insight as to the most effective and economical way of controlling the spread of this disease. Go to and then click on “about us” at the top of the page. I also have taken the liberty to forward this message to Kasia Kinzer, NDSU plant diagnostician, in case she has anything else to add.

Q: I came across your e-mail address while trying to find information on how to propagate a kalanchoe cutting. I found a cutting of a large kalanchoe leaf with some of the stem connected to it. I brought it home and stuck the stem part into the ground so that it is now upright. Is that the right position to propagate it? (e-mail reference)

A: Assuming the cutting you found had a chance to callus over a little before setting it into the soil, it should root for you in a few weeks. For my publication on propagating techniques, go to

Q: I found your website, so I am hoping you can give me a quick answer. I dug up some iris rhizomes last year. I’ve since planted most of them but still have about 20 left. They are very dry. Are they only good for compost or can someone plant them? (e-mail reference)

A: I'd try giving the iris a shot at growing. Pick the plumpest or heavies and plant them with a good dose of water. Some are bound to come up. Any that are puckered are ready for composting.

Q: I was wondering if you could give me some advice on how to eradicate burdocks from a pasture? Should I pull the plants out? If so, when should I pull the plants out? Can you burn them? Should you spray them and what should you spray them with? If we cut them, will they grow again from the root? I’d appreciate your help and my horses also will thank you. (Twin Brooks, S.D.)

A: Burdock is a biennial that starts out the first year as a rosette, then bolts the following growing season to a stalk from 2 to 6 feet tall. The stalk is covered with burs that stick to anything that passes by, which causes widespread distribution of the seed. Unlike some other obnoxious weeds, burdock has a single, large taproot, so it can be dug up if you want to. Burdock also can be sprayed. The most effective time is spraying the first year during the rosette stage. Any product containing glyphosate will do the job. Keep in mind that glyphosate is a nonselective herbicide, so the spray must be directed carefully at the target plant to avoid collateral damage to the surrounding plant material. Cutting them down and then spraying removes the surface area needed to get effective herbicide control. I would suggest opting for the nonselective herbicide unless you have a countable number that is low enough for you or someone with a strong back to dig them out.

Q: I have a 5-year-old evergreen that has browning at the bottom. The discoloration is working out from the trunk to the branches. This problem started about two weeks ago. Is there anything I can do to try to reverse this process? (e-mail reference)

A: With winter weather closing in, I suggest getting out and pruning the affected branches back to the trunk of the tree. This is not the best time for doing this, but the spores will not be active for the next several months. Next spring, you can take another look at the tree to see if this problem is continuing. If so, then a branch sample should be sent to the plant diagnostic lab at your state land-grant university for a lab culture and analysis. The lab also may suggest a course of action.

Q: We purchased 20 acres of land in central Kansas. We want to plant some fast-growing trees as a windbreak and privacy from our neighbor who likes to put junked cars in his yard. I was reading about Lombardy poplars, but decided they are not what we want. What do you suggest we plant? We've planted more than 100 eastern red cedars, but they are growing very slowly. Deer also are a problem because they have eaten the tops off or just yanked the trees out of the ground. (e-mail reference)

A: You are in the shelterbelt capital of North America! For more information, go to or go to the Kansas State University Extension Service website at To reinforce your judgment on Lombardy poplars, there have been too many problems with this tree, especially when they are just starting to provide the benefits you want. There are many better trees that the local Natural Resources Conservation Service or Extension Service can recommend.

Q: I ordered two yellow primrose lilacs. I know they are supposed to be planted in the fall, but I expected dormant trees and what I got is two 4-inch-tall green plants. I am debating whether to plant them outdoors now or pot them and keep them in the house until spring. I am afraid they will die if I put them out now. (Jamestown, N.D.)

A: Get them planted outdoors as soon as possible. Hope that winter will arrive gently enough so that the plants can acclimate to the conditions. I would advise covering them with a sheet of geotextile before the worst of winter arrives. Another possibility is treating the plants like they are borderline rose bushes and put cones over them and then pile soil around the base. Keeping them indoors for the winter will not do the trick. The lilacs have a better chance of becoming the shrubs you want by exposing them to the elements they will be living in.

Q: I was wondering if it is too late to plant bulbs. If not, how much time is left? Also, when fertilizing bulbs that I planted last year, do I rake back the mulch and sprinkle it on top of the soil? These would be spring-blooming bulbs. (e-mail reference)

A: I’m going to assume that you live in North Dakota, Minnesota or South Dakota. If I am correct, then you should know that fall bulb planting is now on borrowed time. It should have been done earlier, but since it wasn't and the frosts have been light enough that the soil is not yet frozen, you should get them planted as soon as possible. Most spring-flowering bulbs don't need fertilizing unless they are in almost pure sand. I wouldn't bother with this unless the plantings showed some kind of nutrient deficiency or were punky in their flowering.

To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail

NDSU Agriculture Communication

Source:Ron Smith, (701) 231-7123,
Editor:Rich Mattern, (701) 231-6136,
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