December 20, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: This year almost all of my tomatoes split on top. The bottoms were fine. I kept them watered and mulched. Why did this happen? Also my ferns got brown and dry by the middle of August. I think it may have been from the hot wind. Could that be? (E-mail reference, northern South Dakota)

A: Sometimes it has to do with the variety of the tomato, and it usually affects the first fruit setting the most. I would suggest considering another tomato cultivar (variety) next spring, since it appears that you did everything right this year. Concerning the ferns, the wind could very easily be the cause. Some ferns are tough and will bounce back next spring, so don't give up hope just yet.

Q: I've saved two stems from a rotted Sanseveria cylindrica plant and want to root them. Do I need to let the ends dry out? I've read conflicting things, from several hours to a week. (E-mail reference)

A: You raise an interesting point. I never knew there were conflicting opinions. When I taught the plant propagation class, we would take leaf cuttings and, making sure we did not reverse the polarity, cut the base straight across, the top with a slanting cut, and insert the straight end into the rooting medium, with no waiting and with success. Leaf cuttings of Sansaveria take a long time to "root" because they actually do not! What happens, is they form a rhizome from that cutting, and from that, a new leaf emerges, with the old leaf eventually disintegrating.

Q: I bought a Norfolk pine last year and it was beautiful and full. It was growing nicely, so I transplanted it into a larger container last month. Now it is getting dry brittle branches and is dying. Is there any way to save it? (Jamestown, N.D.)

A: Start immediately to mist the pine with distilled water on a daily basis. As the outdoor temperatures go down, increase it to twice daily. Be sure the plant is not near any heating vent draft. If it doesn't stabilize, then our action has come too late, and you need to start anew with another plant.

Q: I have had my garden in the same spot in my yard for the last four years and not had any kind of a problem until this year. Early this spring I noticed some creeping Charlie coming in. If I kept ahead of it I then kept it under control, but when I left for vacation and came back the garden was just covered with this awful stuff. I spent a week out there pulling "Charlie" by hand out of everything. I thought of using Roundup, but, knowing what that would do I chose not to. Now of course it is all over, including the strawberries. What do you suggest that I do now that everything has been harvested? (Chancellor, S.D.)

A: Can I wish you had used Roundup? Anyway, nuke as much of it as possible without doing damage to your other crops with Roundup. It breaks down immediately in the soil, so leaves no residue. Then, I suggest digging out your strawberry plants, killing off the creeping Charlie with Roundup or ripping it out entirely, and resetting your strawberries. This would be best done in the early spring.

Q: Last fall I had four bull pine (long needle) trees moved in by a tree service (transplanted from his tree grove). They were about 10 to 12 feet tall. They were staked down and watered well last fall. This spring they seemed to bud out but then stalled and eventually died and had to be replaced. The tree service person thought I killed them when I spread my weed and feed on the lawn. Is it possible that normal fertilizer and weed killer applied to the lawn would kill a tree of this size? If it is true, how far away do I have to stay with the application of weed and feed to the surrounding lawn? (Jamestown, N.D.)

A: I am going to answer your question as gingerly as possible to try not to hurt anyone's feelings.

First of all, if the tree roots were not pruned for a year or two before being moved, then about half to two-thirds of the tree roots were left behind. The tree spade will dig a ball of earth/roots about 44 to 48 inches in size. Trees the size you described have a very extensive root system beyond that. This translates into insufficient root mass to pick up nutrients and water to deliver to the tree needles, which could result in the death of the tree. Next, the "weed and feed" combination is so weak in the active ingredient (AI) that it is lucky to get weed kill, let alone kill a tree. Besides, there are a couple of weed and feed types. One that is used for pre-emergence treatment controls mostly annual grassy weeds, and the other controls the perennial broad-leafed weeds, like dandelion and plantain. If you got under the canopy of the trees with the first, no damage would likely occur. If you got under the canopy of the trees with the latter, there is a chance for damage to occur, but not likely. Notice I said under the canopy of the trees. I doubt that you did that, and I doubt that the tree roots would have grown out that far in just one growing season. My analysis of the situation is that the trees died because of root system loss, unless the tree mover will back up any claim that the tree roots had been pruned for at least a year or two before being moved. If they came from a "tree nursery" they were probably pruned on a regular basis to build a nice tight root system. If they were simply dug from a shelter belt, I wouldn't bet the family car that they had been pruned.

Q: I have two beautiful Christmas cactus getting ready to bloom. What is a good watering schedule or when can I tell when they need watering? (E-mail reference)

A: Whatever you do, keep the soil mixture continuously moist, continuing the same pattern you have been following up to this point until after the flowering period. If you alter it too much now, the blossoms are likely to abort and you would end up with no show. Do not allow the pot to stand in water after watering. Pour off the excess. After flowering, moderate your watering to just moisten the soil mixture throughout, allowing the top inch to dry before watering again.

Q: Would it be all right for me to do some major trimming on my Sioux Land trees this fall? They have most of their leaves. I guess our freeze hasn't been hard enough for them to drop. (E-mail reference)

A: Late winter, the beginning of March, would be a better time. The wounds from pruning would not heal in time if done now and may lead to some winter kill. If you must prune now, remove only the dead, diseased or broken branches.

Q: I have seen bright red-leafed smaller-sized bushes in the landscaping of new homes in and around the Minneapolis area. They are a deeper red during the summer and a bright red in the fall and are outstanding. What are they and will they grow in North Dakota? (Harvey, N.D.)

A: I think what you are talking about is the purple leafed barberry, which in most cases is actually red, and even redder in the fall of the year. Yes, they will grow in most of North Dakota.

Q: My mother-in -law has some plants (china doll, jade, Christmas cactus) in an entryway at the top of the stairs to the basement. She said they do just fine all summer and fall until they turn on a propane heater in the basement. Then the leaves of the china doll fall off and the Christmas cactus stop blooming or lose blossoms. (E-mail reference)

A: The plants are acting as the miner's canary. Your propane heater is giving off toxic fumes in low concentrations that the plants are responding to. Your mother-in-law is taking a chance with her health. I suggest venting or modification of the system in some way before regrets become reality.

Q: I just realized that I have a layer of mold (it appears to be mold/fungus) on the soil of my schefflera. How does this happen and what can I do to prevent it from happening again? (E-mail reference)

A: Usually from slow or poor drainage, keeping the soil too wet. You can eliminate by surface cultivation or better yet, repotting with sterilized or pasteurized soil. Nothing to worry about from a plant health standpoint, it is just a saprophyte.

Q: I recently bought two spider plants, took them out of the plastic containers they were in and repotted in clay pots and then hung them in my bedroom. I gave them plant spikes, watered with distilled water a couple of times a week, and the leaves are turning brown and they look like they are rotting. Any suggestions? (E-mail reference)

A: The first mistake was with the plant spikes. If they have not completely dissolved, take them out. Secondly, watering once a week should be sufficient. If the plant is in a non-free-draining container, get it out of there ASAP. Next, are they growing in full sunlight? If they are, the sunlight will scorch the leaves, which could mimic the turning brown you mention. Also, does the potting soil mix have any perlite in it? If it does, that too could be a source of discoloration of the leaves, especially at the tips, from the fluoride the perlite contains. The solutions are obvious: move the plants away from direct sunlight to something more diffused; repot in a medium that is well-drained (along with the container) that is free of perlite. Fertilize with a water-soluble material like Schultz Plant Food Plus (10-15-10) or something of equal quality about once a month.

Q: I have always heard that you need two apple trees (not necessarily the same variety) to get reliable pollination. How far apart can the trees be and still get reliable pollination? Are we talking tens of feet, or hundreds of feet? In my case, if I planted a single tree, the nearest tree would be a crab apple about 150 feet away and the nearest apple (probably a Haralson) would be about 350 feet away. (Ashby, Minn.)

A: You have nothing to worry about. The bees will do the work for you at the distances you mention. You should get excellent fruit set.

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