NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

May 4, 2000

Hortiscope

Ron Smith, Extension Horticulturist
North Dakota State University

Q: I need some help. I don't remember how much room to leave around a shrub when you put down the fabric weed preventer. I would appreciate your letting me know even if I am a Florida resident. (Florida e-mail)

A: You simply cut an X in the fabric larger than the potted plant you are installing. The cut ends of the X can then fold back to the plant stems. Check annually to be sure it isn't girdling any stems. If it is close to doing that, then simply cut some of the fabric away to make more room.

Q: Do you know of any way to keep cats out of flower beds? (New Town, N.D., e-mail)

A: Try moth balls; cats find the odor repugnant. Or, try planting catnip in another area, and they will be attracted there instead.

Q: I've been in this house less than two years and have a lot of lilacs. I plan to increase my collection by purchasing different varieties as well as planting more of the suckers (which seem to do quite well) to surround the property for a lilac-enclosed paradise. I'd like to know exactly where one should cut the bush to prune for maximum bloom while retaining as much height as possible and making the bushes plump out next spring. (e-mail)

A: Take some long-handled loppers and reach into the base of the lilacs as low as possible and cut back about one-third of all the oldest canes. This would leave about two-thirds left for the bloom show and cause the plant to "plump out" as you put it (nice term, I like it!) next season. Do that each spring and you will have perpetually beautifully lilacs to enjoy.

Q: I was just wondering if it is to early to plant strawberries, in Lisbon, N.D.? (Lisbon, N.D., e-mail)

A: I would suggest waiting until we are into a more settled weather pattern. I hate to give dates because the weather in spring is so fickle, but I would guess between May 1 and Mother's Day (May 14) should be OK.

Q: I have been planning on taking down the old boxelder trees in my yard and replacing them with others. Gurneys has a Douglas pear tree that is rated for zone 4, and a Reliance peach tree rated for zone 4 as well. I would like to know if these do well in our area since we are on the border of zones 3 and 4. Or, do I need to stick with zone 3 plants? I am a novice at gardening and have never quite figured that one out. (Lisbon, N.D., e-mail)

A: Stay with the plants rated for zone 3 or zone 2. I'm afraid you'll be disappointed if you don't.

Q: I was given a Christmas Cactus that has probably been in the same pot for 30 years. It just had two blooms on it. Any advice on when and how to repot it would be helpful.

Also I started my dahlias indoors and they have really taken off. Should I cut them back? Some are 10 to 12 inches tall with lots of leaves. (Sheyenne, N.D., e-mail)

A: Thirty years in the same pot! That has to be a record. Typically, this type of cactus is potted after flowering is completed, which it should be now. It would also benefit from a summering outdoors in a shady location.

As for the dahlias, yes, cut them back somewhat, and move them out doors during the day when the temperature is 50 F or higher to begin slowing them down and acclimatizing them.

Q: I have started seedlings indoors, and now that they are up--under a fluorescent light and as green as can be--how do I minimize or strengthen the lanky stem? I have a fan available to circulate air, but I fear the air may be too cool, as I see a bit of brown on a couple little leaves (they just have two leaves now). How often shall I have the fan on? (Williston, N.D., e-mail)

A: If the fan is moving the ambient air that is normally in the room for humans, the air should not be too cold. Just don't make it too strong! Lower the temperature somewhat, or expose them to stronger light, by moving the light fixture closer to the plants. Moving them to a sunny window would also help. Don't be afraid to pinch them back either.

Q: For the past two years (and at two separate homes located about 70 miles from each other), I've planted crocus bulbs in the fall. The following spring, instead of having blossoms, the bulbs send up shoots that look like long blades of grass. I've tried different types of crocuses with the same results; however, three years ago, I planted crocuses without any problems. Is this a soil issue? (Grafton, Wis., e-mail)

A: Could be cold damage to the floral part of the plant or physical damage in handling (digging them at the nursery, most likely). They are usually crowbar tough plants that need little to no concern horticulturally.

Q: We have an area that we would like to plant solid with perennials that are low maintenance. The area is located on the east side of the house so it gets full sunlight for part of the day, and then is shaded the rest of the day. What do you suggest? (Williston, N.D., e-mail)

A: Some of my favorites include the following:

Q: I've read about grape tomatoes and the variety Santo or Santa. Do you know if they are hardy for our area, and what varieties would be recommended? (Cando, N.D., e-mail)

A: You want to order the Santa hybrid, which matures in 55 days.

Q: Last year I had a problem with worms (wireworms, I think) in my potato patch drilling holes in them. How can I get rid of them organically? Will lime have any effect on the wireworms? Do you think they will be back this year? Also, can potatoes and sweet corn be planted side by side? (Tappen, N.D., e-mail)

A: I would suggest using Bordeaux moisture, which is an organically acceptable combination of copper sulfate and hydrated lime. It provides both insecticidal and fungicidal protection. I would dust the potato seed prior to planting and dust around the planting hole as well.

Q: I live in Kansas City, Mo., and from all of the information I have read thus far, the problem with my tree appears to be a frost crack. I still need to know what effect it will have on the tree in the long run. We think the rabbits got to the trunk late last fall. They ate the bark all the way around the trunk. The split happened at some time during the winter. We first noticed it in January. (e-mail)

A: A girdled tree has no hope of recovery, so you are better off replacing it. The vertical split is known as sun scald but is really caused by frost splitting the trunk after it has been warmed by the sun during the day. In the future, wrap the tree in the fall with some horticultural tape or plastic to both keep the rabbits away and to keep the bark protected from the sun while the tree is still young.

Q: I started a tray of pumpkins a couple of weeks ago, just for a trial run. I put them in newspaper-lined plastic strawberry pint-size containers. They are doing great and the roots are easily passing through the newspaper. Here's my question. Since they are so fussy about disturbing their roots when transplanting, is it going to be a problem since some of the roots are intertwined with their neighbors? (e-mail)

A: Probably. Best to do the transplanting in the cool of the late afternoon or early evening to minimize stress. Of course, handle with care. They should recover with a little TLC without any problems. I still think you are a little early. Good luck!

Q: I recently trimmed my lilac bush and kept several branches that had little nubs. I have them in a jar with water, and they're almost in full leaf, with some of the tips having tiny little green lilacs opening up. I would like to transplant them to a different part of our yard. Will they sprout roots in the water, and if so, how long should the roots be? Also, when should I plant them? The original bush is in full sun, but do my transplants have to be? (Bordulac, N.D.)

A: Lilacs can be rooted in a sand/peat or vermiculite medium, if careful attention is paid to timing. When the new, green shoots reach a length of 4 to 6 inches, cut them off and trim into cuttings. Being very succulent at this state, it will be difficult to prevent wilting.

From a homeowner's perspective, it would be best to have some distilled water handy in a mister, and as soon as the cuttings are harvested, mist completely, and cover with dampened paper towels until they can be stuck in the rooting medium. Mist regularly, and they should root in about six weeks. Lilacs must be planted in full sun or the flowering will be greatly reduced.

Q: I received a Amaryllis bulb gift at Christmas and I planted it per instructions, and in time it produced beautiful flowers. After the flower faded two seed pods came on. They have now dried and opened and are full of wafer thin black discs like seeds(?). Can you please explain them? (Wessington, S.D.)

A: It's simple: the plant engaged in sexual reproduction. The Amaryllis flower has both staminate and pistillate (male and female) components in it. The pollen simply transferred to the sticky surface of the stigma, germinated and grew into the ovaries. What you now see are the mature seeds, which you can try sowing and see if they grow. It will take about three years to develop the bulb equal to the size and quality of the one you received.

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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.

Source: Ron Smith (701) 231-8161
ronsmith@ndsuext.nodak.edu
Editor: Dean Hulse (701) 231-6136