Q. There's poison ivy growing at the edge our lawn. Is there any fool-proof way to get rid it ? A. After growth starts in the spring, spray the foliage with Amitrole, sold under the trade names of Poison Ivy Killer, Wedazol, ATA. Keep it off the plants you don't want to hurt, including the grass. Read the directions on the label and follow them closely. Q. Several years ago I planted daffodil bulbs that came from Holland. Now I get beautiful leaves but no flowers. What's wrong? A. As the years go by, daffodils multiply; when they become crowded in a clump, they stop blooming. Usually they need to be dug up and separated every four or five years. Do it after the foliage dies in the spring. Q. I planted seeds of tomatoes, peppers and eggplants. They came up fine but whey they were an inch tall they bent over and died. What caused it? A. It's usually due to a fungus disease called damping-off. The small seedlings are attached near the soil surface, the stem rots, and the plant topples over. This can be prevented by sterilizing the soil and tools. It can also be done by planting the seeds in shredded sphagnum moss. The thread-like moss must be shredded to a fine consistency; or a purchase shredded sphagnum already prepared for seed sowing. Q. Is there a way to remove daffodil bulbs planted too close to shrubs without damaging the shrubs? A. Lift the bulbs in early spring with a spading fork and replant them elsewhere. In early June dig them again, separate them and replant them. In early spring any damage to the roots of the shrubs will be compensated for by new growth. Q. I really love vegetable gardening, but I worry about plant diseases. Is there a single pesticide I can use to protect the plant from infection? A. To be successful with fungicides for disease control you must have the right material by the right method at the right time. Seldom can a fungicide cure; it can only prevent infection in most cases. Q. My crocus bulbs did not bloom this year. Can you tell me why? Most of them were planted about eight years ago in the fall. A. Like most other hardy bulbs, crocus eventually becomes crowded and should be taken up, separated and immediately replanted. The best time to do it is after the foliage dies down in spring. Q. We used to have a good lawn but now it's mostly weeds. When is the best time to kill the seeds and sow grass seed? A. The best time to seed the lawn is late summer but it can be done successfully in the spring. Q. My rhododendron has become leggy. How much can it be pruned and when's the best time to do it? A. Prune leggy rhododendrons immediately after they bloom and they can be cut way back almost to the ground. Pruning encourages new growth and results in a dense landscape plant. Q. Last year the bottoms of my beefmaster tomatoes split open when they started to turn red. What would cause this and how can it be prevented? A. Too much rain (or irrigation) when tomatoes are ripening could do it. The flesh of the tomato swells faster than the skin expands, and the skin splits. Don't overwater. Q. I want to put up an outdoor security light, a few feet away from my garden and about 15 feet high. Would this affect plant growth? A. Just as few plants can grow without any light, few plants can grow properly without some period of darkness. If the light intensity is low, maybe little harm will be done by it.