Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have a large 8-foot schefflera and two diffenbachia plants that have little black bugs I have been unable to get rid of. The leaves look sickly and are gradually turning yellow and then dropping. My next option will be to cut them back and hope that breaks the cycle. The bugs have been laying eggs that you can see. I hate to cut back the schefflera but it’s apparently gradually dying, and due to the size and location of this plant I do not want to spray any chemicals. How would you go about getting rid of the bugs or cutting back the plants. (E-mail reference)

A: You have to make a decision as to whether or not the plant is worth saving. If the damage is too extensive for the plant to recover and be an asset, you are better off dumping it. If the decision is made to keep the plant, then I'd suggest getting one of those "No-Pest" strips and a large trash bag. Place the strip on the soil in the pot and put the bag over the entire plant, tying it to the base of the container. Keep it like that for 48 hours, then uncover and dispose of the strip properly. Wear protective (disposable) gloves when handling the strip. Another alternative is to spray the plant with insecticidal soap. This is a special long-chain fatty acid that kills on contact, so complete coverage is necessary. This is completely safe to use indoors around humans and pets. It still may be a good option for you to do some trimming on the worst areas of your plant.

Q: My cyclamen has finished flowering and is dormant, apart from what looks like a seed pod. Do these plants have a seed pod, and if so, how do I treat the plant/pod, how long does it take to mature, and can I grow them from seed? (E-mail reference, Tasmania, Australia)

A: Yes, those are seed pods that are on your plant. Collect them and sow the seeds within them in a cool location in richly humus soil. Keep the seeds covered, and in about three to four weeks some emergence should be apparent. If you can keep the temperature between 62 and 64 F. at that time, it would be perfect. It takes between one and two years for the plantlets to reach sufficient maturity to flower. Be sure to keep them shaded to prevent sun scald. Since your seasons are the opposite of ours, it will be difficult to keep the plantlets cool enough. You may have better luck storing the tuberous plant dry in the container in a cool location until your fall -- March or April- - when (if you are lucky!) you should see some new growth emerging, and you can begin the whole cycle over again. Generally, they are such fussy plants to grow that the standard recommendation is to discard them after they have finished flowering. Cyclamen growers are specialists that have learned all the nuances of growing them. I certainly don't consider myself one, as I've taken the easy road out and dumped them after they flowered!

Q: Please identify the enclosed evergreen for me. Many of them come up in my garden, but I don’t know where the parent tree is located. They are a nice green during warm weather, but turn purplish for the shorter days. (Jamestown, N.D.)

A: Your evergreen is a juniper. The seed is eaten by the birds, and once it passes through their digestive system they readily germinate.

Q: Could you please send me information on how to start apple trees from seed? Would like to start the trees in a light soil, in grass area that has never been planted to anything but prairie grass. A lot of sun, near other trees. (E-mail reference, Dundee, Iowa)

A: Your success will depend on a number of factors, first being the variety of apple you will be using for the seed source. Seedlings of 'Delicious', 'Golden Delicious', McIntosh', ''Winesap', 'Yellow Newtown', and 'Rome Beauty', are the most widely used sources for good rootstock development. If you suffer from extreme prairie cold like we do in the Dakotas, you might want to get some Siberian crabapple seed (Malus baccata) for the hardiness such rootstock can impart to the edible scion wood. Although apple seed needs about 120 days of stratification, this can very easily be met by direct sowing outdoors. I advise you to sow much more than you think you'll want or need. That way you can select the most vigorous plants for further development.

Q: What can you tell me about "Lemon Grass?" I was curious and purchased some. It is potted and growing very well. Will it produce lemons? (Jamestown, N.D.)

A: Lemongrass -- Cymbopogon citratus-- doesn’t produce lemons, but it produces a lemon-like scent from the essential oils that are in the leaves. Bruise or break a leaf and you will note the lemon fragrance. This plant is used in Sri Lanka and Thailand for food preparation. It is also used medicinally in Brazil and Caribbean to settle nervous stomach disorders. The Cubans use it to control ring worm and lower blood pressure. What more could we ask of a plant?

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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: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu