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

By Ron Smith, Horticulturist

NDSU Extension Service

Q: I am hoping you can suggest a shrub for me. The area has an eastern exposure and is in light shade throughout the day. We are looking for something in upright form that will grow to be 6 to 8 feet tall and shouldn't get more than about 4 feet wide. It will be planted next to our house entryway, so we don't want anything with fruit or that is messy. The shrub needs to be resistant to fire blight because we had a columnar buckthorn planted at that spot that died of fire blight. It can be a deciduous or evergreen shrub. Our soil is good and can be watered easily. (Eureka, S.D.)

A: Plant a wine and roses weigela or a little lamb hydrangea. Both fit the criteria you are looking for.

Q: I keep searching for deer repellant techniques on the Web. I planted hundreds of white pine saplings on some vacant property but many were destroyed by deer. My most economical solution is to wrap the trees with clear, heavy-duty plastic wrap. You can purchase the stuff in 2-foot bulk rolls. They also make a holder with a knob on top for putting the wrap on the trees. A roll runs about $14, but we have not used an entire roll in three years. We just wrap the trees before the deer rut at the end of October. We remove the wrap in early spring. Because it is a clear material, it lets the sun through and holds moisture in as well. On some trees, we put four stakes around the tree and then wrap around the stakes. Anyway, just thought I'd share the idea with you. (e-mail reference)

A: This is a unique way to protect the evergreens and give them a chance to get established. Thanks for sharing your idea. I'm sure many readers who have been battling deer for years will give your suggestion a try.

Q: We have two beautiful red splendor crab apple trees. Each spring, robins pluck the fruit from the trees down to the last morsel. This includes any fruit that was on the ground. However, it didn’t happen this year! Not one robin or any other bird has been active on the trees. While walking the dog this past weekend, I noticed that other crab apple trees in the neighborhood also were loaded with fruit. Did the fruit turn bad this year? As the trees start to flower, will the old fruit fall off? This always was one of the special attractions of the red splendor. (Fargo, N.D.)

A: A lot depends on other food sources in the area. If there is a shortage, then the remaining fruit becomes a prime target. If there are other goodies available that they have a preference for, they go for that first. As the tree continues to open with foliage and flowers, the old fruit either will fall off or disintegrate.

Q: You mentioned that your wife is a square foot gardener. I built three last summer and filled them with the soil mixture recommended in the book. The boxes could use a little topping off this spring. What can I add to bring the soil level back to the top? The National Weather Service’s long-range outlook for the northern Great Plains is calling for below-normal temperatures for this summer into fall. What can I do to be more successful than last year with peppers, tomatoes and eggplant? Floating row covers or that clear plastic with holes punched in it? (Mandan, N.D.)

A: Solarizing the soil with clear plastic will raise the temperature and keep it higher for a longer time. Covering the plants with a row cover also may help stabilize the temperature swings. If you really want to push it, go for the clear plastic and make an open shield around it that reflects the sunlight and heat.

Q: Two weeks ago, I planted 24 emerald green arborvitaes. The leaves are getting black tips along the outer edges of the branches. These dry tips can be knocked off with a fingernail. The foliage inside the trees is green and healthy. The arborvitaes were planted to be a living fence. There appeared to be some discoloration of the tips when I picked them up but otherwise they looked good. I was told they had been fertilized with 16-16-16 about three weeks before. All were planted within four days after purchase. I planted them with continuous-release fertilizer in the bottom of the hole and have watered by hand each tree for about a minute every day, except yesterday after reading your website. I lightly mulched with chipped cedar bark. (e-mail reference)

A: It is good that you stopped watering every day. I would advise that you not water again until the soil feels dry down to about 3 inches. Then give it a good soaking and stop. Wait until the soil is dry again. The added fertilizer was not needed. However, the fertilizer should not pose a problem. All you can do now is wait to see if the plants can pull out of this downward spiral. I'm betting that they will if you didn't plant them too deeply.

Q: My grandmother planted a couple of lilies of the valley years ago. Now they are everywhere! I've spent about 10 hours digging them up. However, I didn't dig deep enough, so I left a bunch of roots. Two days later, they were popping back up and spreading out. I went back to work to dig deeper and start pulling out the roots. However, there's so many that I never will be able to find all the roots to pull them out. (e-mail reference)

A: You are doing the best thing to get rid of this invasive groundcover weed. It is the rhizomes (underground stems) that keep coming back, not the fine roots that you see by digging so deeply. The rhizome is a fleshy extension coming from the crown of the plant. Once you are done, that should be it. If anything else should pop up, get a hold of some glyphosate (Roundup or an equal) to knock it down and save your back. After that, sit back and relax because the battle is over. You may get a sniper or two, but they can be killed with the right chemical.

Q: We had a wet start to April. During the past few days, I've noticed three of my blue spruce looking a little stressed. The trees are losing their lush, dark green color and have some yellow tint on the needles. They are planted on a berm, so they are not planted too deeply. The buds seem OK. If this is a symptom of overwatering thanks to Mother Nature? Can anything be done to help the trees? (e-mail reference)

A: There is nothing you can do except wait and hope for the best. Blue spruce trees don't thrive in wet soil conditions, so you were smart planting them on a berm. The best looking blues I have seen are those planted in a similar manner. My other concern might be the soil composition used in making the berm. Topsoil is stripped from one part of the earth to another and may or may not have herbicide residue in it. Another possibility based on the superficial information provided is an excessive level of salts in the soil. This can be determined by taking a soil sample to the land- grant university in your state and having the soil testing lab test for salt levels. If that is the case, the salts should decrease with rain and watering.

Q: I bought one of those composters that you can turn with a handle. It said on the directions that to make compost, the temperatures have to stay above 50 degrees at night. That is a very short part of the North Dakota year. Can I still put banana peels, eggshells, coffee grounds and other material in it during the winter? (e-mail reference)

A: If you do, it will not heat up enough to convert it into compost. It will become frozen garbage and won't turn to compost until the next warm season.

Q: My friend's Boston fern has been around for many years. For the last 35 years, he has done nothing except water it. He says the roots are growing out of the top of the soil but is afraid to transplant it. Any suggestions? (e-mail reference)

A: If he doesn't want to divide the fern, transplanting isn't necessary. He can just move it into a larger pot. If he does, now is the best time (spring) to do so. Depending on the thickness of the crown and rhizomes, use a pruning shear or a very sharp, big knife. It can be divided in half, thirds or quarters. Be sure the crown is not buried. It should be at the surface of the soil.

Q: My blue spruce trees fit the description of having needle cast. Last year, the needles started turning purplish brown from the bottom up and then needles started falling off. The product that was mentioned several times to prevent or help cure this problem is Bravo. After an extensive search, I found the product in a 2.5-gallon container. How do I dilute the stuff? It sounds like a stupid question, but all the data I found gives the ratio per acre. I am not spraying the whole property. (e-mail reference)

A: The conversion rate per gallon is 1 level tablespoon per gallon of water. Bravo has chlorothalonil as the active ingredient, which is a broad-spectrum but very effective fungicide. Timing is as important, if not more, than the rate. You want to time it as the new growth is about half-elongated and again when it is fully elongated. This is weather dependent, so you need to be vigilant. Warmer weather will accelerate growth, while colder weather will slow it down. It is important that you get the second spray on to give the new growth protection. You should be aware that this disease can be spread through cultural methods, especially pruning tools. Take care when or if you do any pruning that you don't go from infected or symptomatic branches to healthy ones without sterilizing the cutting tools.

Q: We have several clumps of iris plants. One has bloomed very nicely every year. The other two clumps have yet to bloom. They get approximately the same amount of sun. The clumps that are not blooming get more rainfall. I can’t see a difference in their planting depth and I do not see any pests or diseases. They are all healthy looking clumps. Is there a way to identify the iris type without the blooms? Should I thin out the clumps and give them another couple of years? (e-mail reference)

A: I don't know of anyone on this planet who could identify the iris without flowers. Someone may roughly identify the type. We have to wait until they bloom, then get out an iris photo book to make an identification. It wouldn't hurt to divide them and give them a couple of more years. That is assuming nothing happens this year.

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) 231-8161,
Editor:Rich Mattern, (701) 231-6136,
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