November 1, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: What is this plant that is growing in my garden? Is it a weed or a desirable plant? (New England, N.D)

A: It appears to be skeltonleaf bursage which is a perennial that spreads by seed and rhizomes. The samples you sent had not developed rhizomes because they were immature. Try to hand pull as many as possible this fall and generously mulch your garden with 3 to 4 inches of bark or peat moss.

Q: I have horseradish taking over everything! How can I get rid of it? (Alcester, S.D.)

A: Horseradish, when it behaves like a weed is extremely hard to control. There are a number of products to try, but I’d suggest giving Roundup the first shot. It that doesn’t do the trick get back to me and I’ll confer with the best weed control minds in the country to figure out a way to control it for you.

Q: Can you identify the enclosed sample? Should it be removed? (Glen Ullin, N.D.)

A: It looks like the Nanking cherry, Prunus tomaentosa. This is a shrub that gets to 10 feet in height and 15 feet in spread. It flowers early and fruit ripens in June and July. Removal is your decision.

Q: Are the enclosed leaves from two different trees? They are on the north and south sides of my yard. If so, what kind are they? Is there anything I should watch out for with these trees? (Osage, Minn.)

A: Both trees are Amur maples, Acer ginnala. What you are seeing is leaf dimorphism--variations within the species. Watch these trees for iron chlorosis. I suggest using Miracid to keep the microelements available.

Q: I have brown worms that look like meal worms eating the leaves off my small oak trees. They are leaving the vein part but stripping the leaves clean. There are literally hundreds of them and my extension agent is on vacation. Can you please help before my trees are killed. (E-mail reference)

A: Not to worry, the trees will survive. Spray with either Malathion or Sevin ASAP to get a kill-down. Then spray with a dormant oil spray next spring before the trees leaf out to kill any overwintering insect eggs.

Q: This is our third summer in a house with a large hackberry tree over part of our deck. This year it has produced a large amount of sap, much more than the last two years. It also has feathery little aphid type insects on it as well as a number of ladybugs that I imagine are eating the aphids. Does this tree have varying sap cycles? Is there anything we can do? Our deck and furniture and a lovely fig tree are turning black and sticky! (E-mail reference, Huntsville, Ala.)

A: I hate to tell you what it is that is dripping on your deck and fig tree, but I must. The "sap" is the "honeydew" from the aphids feeding. It is technically the sap of the tree, but only after it has passed through the gut of the aphid. The ladybugs will take care of them eventually. In the meantime, I suggest an umbrella covering for your fig to keep the fruits more appealing and to prevent a secondary fungus or mold from developing. Next spring you might want to contract with a competent arborist to control these pests. There are systemics available that will not harm the predatory insects like the lady beetles. If you lack the patience for the lady beetles to do their work, you might contact that arborist now to spray the tree with Neem. It is an organic that would take care of the aphids as they feed and not harm the lady beetles.

Q: I have a problem with rabbits eating my petunias. I have used a spray and that slows them down a bit. I also bought a live animal trap but they never go in there. Any suggestions on bait and placement of the trap would be appreciated. (Brentwood, Tenn.)

A: We have the same problem up here as well. We call them "urban livestock!" We use a live trap and lead a food trail right into it (lettuce, rabbit food, carrots, etc).. Ours are dumb enough to take the bait. We then take them about five miles away and drop them off in a non-agricultural field. Sprinkling dried blood around the perimeter of the plantings will also help, to a point.

Q: I recently planted a non-fruit flowering plum tree. In the beginning I had a problem with the watering level but soon the tree started growing leaves instead of losing them. Also, I just recently planted some mini roses in my backyard that were not flowering brightly and prematurely dying. I purchased rose food and thought it can't hurt to put some around the tree. But can it? Now my plum tree leaves are almost transparent, have a green hue to them, and are falling off. Am I killing my tree or is this the work of some disease?

A: The tree doesn't know the difference. What is good for the rose will not hurt the tree.

It sounds more like a disease. I don't know which one it would be. I suggest taking one to your local county extension office for analysis.

Q: I am a new jade plant owner, but I have this funny superstition about jade plants. My mother always gave them as gifts for people who moved into a new home or apartment. She always said that they will bring good luck. So of course my mother got one for me and I feel as though it's dying or sick or something. It's a medium size plant, approximately a year old (I think), and just looks yucky. I'm constantly picking the fallen leaves up from the floor, and they're tiny. The leaves are not the big, juicy green jade plant leaves that I know. The stems fall off too, and it doesn't seem "strong" to me. I water the thing once per week but was told that they don't need much water so I compromise and use very little water. It really bothers me that I seem to have trouble with this jade plant, as according to my mother, it is supposed to be bringing me luck.

Any advice would be most appreciated. (E-mail reference)

A: From what you have told me, it sounds like your luck may have run out on the current jade plant. I suggest (without telling your mom!) that you acquire another one and treat it in the following manner: Locate it where it will get bright light most of the day (some sunlight is ok).

During the active growth period, keep it in a warm location. In winter, place it where the temperature will not get appreciably above 55 degrees F. Water it on a regular basis during this active growth period, enough to wet the soil mass completely, then allow about two-thirds of the upper soil mass to dry out before watering again. In winter, water requirements are less and watering is needed to keep the soil mix from drying out completely. Fertilize with a standard houseplant fertilizer every other week during this active period; not at all during the winter rest period. If you are attached to this plant irrevocably, then you might find the plumpest leaf and sever it from the parent to propagate. Insert the stem end into a mix of sand/potting soil (50/50).

Q: My perennial bed needs to be redone. When can I move plants most successfully? I am aware September is best for peonies, iris and day lilies, but what about phlox, tiger lilies, etc.? Any help would be more appreciated. (E-mail reference, Iowa)

A: September after a good frost would be a good time to move just about any herbaceous perennial. The old rule of thumb says to move spring blooming plants in the fall and fall blooming plants in the spring. That works, but so does just carefully moving them in the fall. Be sure to water in completely, and don't let them go into the winter in a dry, unprotected state. Put something around them to help catch snow to act as insulation, or simply add it yourself.

Q: What can I do to make tomatoes ripen faster? My plants this year had a lot of foliage. Should I trim that off and if so how much should I trim? Someone had told me not to water the tomatoes after they have set fruit. Is this true, or should I keep watering them? (Battle View, N.D.)

A: Tomatoes suddenly exposed to sunlight after being under a dense canopy foliage may just sunburn. They don't need sun on them to ripen. Yes, water stressing the tomatoes will cause them to ripen faster. Late in the season they should be able to get along on what mother nature provides anyway.

Q: I recently purchased an absolutely beautiful spider plant. It was very large and I noticed there were two mother plants in one pot, so I split them apart and transplanted them. A problem I've been having with them is that the tips are brown. I water them with distilled water (once a week), but it seems that there is also a brown strip running down the middle of the leaf. All the leaves seem very limp and heavy and are breaking. I live in Honolulu, Hawaii. I keep the plants near the window in an air conditioned living room. (E-mail reference, Honolulu, HI)

A: You are killing them with kindness. The spider plant is one of the toughest plants on record, literally thriving on benign neglect. Move them outside in your beautiful climate and let the rainfall take care of watering. Give them additional water only if an extended dry period occurs. The plant is tropical, so it likely is objecting to the air conditioned environment. Brown tips on the foliage is "normal" for container plants; the brown streaking indicates too much water. Are they in free-draining containers? If not, move them there immediately.

Q: I was wondering how I could propagate arborvitae trees from either seed or cuttings. I have heard they are easy to grow from cuttings taken in winter and potted up indoors. Is this true? How hard are they to grow from seed? (E-mail reference)

A: Growing arborvitae from cuttings is so sinfully easy that it simply doesn't pay to try to grow them from seed. Just take cuttings about 6 to 9 inches long, stick them in sand under a mist system (or mist them frequently by hand) and in six weeks there should be an abundance of roots.

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