ASK THE GARDENERS. Q&A.
Q. We have opted for an inner-city house and lot that have great potential. A first priority is to find a fast-growing vine that will cover an old but sturdy lattice fence to give us more privacy, especially during the warm months. What do you suggest?
One of the best is silver-lace vine, or fleece vine, which does well in all but the very coldest or hottest regions of the United States.
It can grow 20 feet in one year and will branch out to cover fences or walls of wood, metal, or concrete within two years without doing harm to any of these building materials. The vine must have a well-drained soil and sunny location. Foamy white flower sprays continue all summer. You may find it listed under either common name or underPolygonum aubertii.m
Dutchman's pipe (Aristolochia durior) is another fast grower. It has large, glossy green leaves and small, inconspicuous - but unusual - meerschaum-pipe-shaped blooms. It will tolerate sun or shade.
Q. Since I am supposed to have a green thumb, a friend gave me some African violet seeds to start, asking that I give her two or three of the started plants. Neither of us knows how long it takes to get a flowering plant, or exactly how to start them. Can you help?
It takes between 8 and 12 months from seed sowing to get a flowering plant. Tiny seeds should not be covered with the planting medium. Sow seeds carefully on screened sphagnum moss or peat-lite mixture (found in garden stores). Mist the top and subirrigate. Make sure the medium is thoroughly moist at all times. Use warm water that is 70 to 80 degrees F.
Give the seed good natural light or fluorescent light, but protect it from the hot sun.
Germination takes about 20 days, so be patient. Summer is a good time to sow seeds, since they need a constant temperature of 70 to 72 degrees F. for good germination. Starting them during the cold months will require a small heating cable or warmth from a fluorescent light that is at a height of about 3 inches above the medium.
Glass or clear plastic over the seed box helps to retain moisture.
Q. Each year we have petunias in a concrete planter attached to a retaining wall. Shrubs, which are planted above, cascade over the wall. Something keeps eating the petunias, which we've already replaced three times. We see nothing on the plants. Everything surrounding the planter is concrete, including the drive, so it can't be snails. What do you recommend?
You have giant garden slugs that come in from the top of the wall at night. Friends of ours had the same situation. We used flashlights to find these night marauders, then put them in a tin can and dusted them with lime. Some were 6 inches long (stretched out).
You can buy snail bait (very toxic, but effective), or you can put household bleach in metal jar lids, placing them every 18 inches.
Q. My husband has always grown handsome glads, but this year the leaves have silvery flecks and the flowers are streaked with white and somewhat distorted. We have noticed some tiny insects that move quite fast. Could this be the trouble?
This is telltale evidence of thrips. This slender, dark-colored insect, about one-sixteenth of an inch long, has a life cycle, from egg to adult, of 2 to 4 weeks and has several generations each season. They overwinter in the ground in warm climates but cannot tolerate a temperature below 40 degrees F. for any length of time.
If possible, store the corms at between 35 and 40 degrees F. during the winter. Also, soaking the corms in Lysol for three hours at planting time (11/4 tablespoons per gallon of water) will eliminate them on the corms. Plant when wet.
You can spray now, but it is hard to get rid of them.
Next year, start spraying when the leaves are 6 inches high. You can use the homemade solution of hot pepper and liquid detergent, 1 tablespoon each in a gallon of water, plus 1 pint of alcohol. Chemical gardeners can use Malathion or Diazinon. Spray every 7 to 10 days.
If you have a question about your garden, inside or out, send it to the Garden Page, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115. Doc and Katy Abraham are nationally known horticulturists.