Gardeners can grow some very nice trees from seed without ever visiting a nursery. You can pick up your own seeds in the wild, and if you're patietn, have a fowering dogwood, an American holly, a pine tree or an oak tree growing in the yard.

Dogwoods come up all over the place from seeds scattered by birds. Birds eat the berries and drop the seeds. To get seeds, don't let the birds beat you to them. And pick berries from trees growing near other dogwoods; seeds will be better with good polination.

Leave the fleshy covering over the dogwood seeds and plant them as they are. Cover them with 1/2 inch of soil and mulch with two inches of tree leaves, pine needles or something similar. They should sprout in the spring. Remove the mulch about mid-April. The seedlings fare best in light shade. When they are eight or nine inches tall, plant them in a permanent location.

Ripe American holly berries can be picked in late fall, early winter and early spring. Remove the fleshy covering and plant them immediately, outdoors, of course, covering them with about 1/2 inch of soil. Mulch them with leaves or straw for the winter. Be patient with them because they usually do not germinate until the second spring after planting.

Seeds from pine cones can be collected in the fall. With most species they're ripe enough to pick when they've turned brown. Trees growing in the open usually provide better seeds than those in the woods, and as a rule, younger trees produce larger seeds than older ones.

Plant pine seeds immediately, 1/2 inch deep. The seedbed should be mulched with leaves, burlap or pine needles until the following spring when germination is well underway. Usually pine seedlings don't require shading after germination.

Ripe oak acorns can be collected in the fall from the ground or picked from the tree.To retard early germination, white oak acorns should be collected soon after they've fallen.

Remove the cap, and plant the acorn 1/8-to one-inch deep, depending on size. Mulch with leaves. In spring after the danger of frost is over, remove the mulch and keep the seedbed moist until after germination.

As years go by and your beautiful pine or oak in the front yard grows and grows, you can get considerable pleasure from pointing to it and remarking casually that you started it from a seed you planted yourself.

O. Can you tell us how to force tulip and daffodil bulbs into bloom? We live in an apartment without access to a garden.

A. Purchase high quality bulbs, free of bruises, and handle them carefully. Plant them in pots with drainage holes. The soil should consist of equal parts potting soil, peat moss, and sand or vermiculite. Now the potted bulbs need 12 to 14 weeks at temperatures ranging from 35 to 48 degrees -- as in a cool cellar, garage or outdoor shed, a dark closet next to an outside wall or in the refrigerator. They must be kept in complete darkness and watered regularly. After 14 weeks the roots should be well developed and sprouts should be two or three inches tall. Put them where the temperature is 60 to 65, with fairly good light, and water regularly. When stems get taller, move to an area that's 65 to 72 degrees.

Q. I have a small greenhouse. Can I grow lettuce in it this winter? Which kind is best.

Indeed you can grow crisp and tasty lettuce in your greenhouse. Grand Rapids is a good loose-leaf type, ready to eat 45 days after sowing; Ruby is another good one, also 45 days; and Buttercrunch, 60 days.

Q. My pyracantha blooms all right, but never any berries. What could be wrong?

A. Sometimes a pyrancantha, nandina or Chinese holly -- all self-polinating -- will bloom but fail to set fruit, or drop the fruit before it matures.This may be because of poor pollination or it may be inherited. Plants, like people, vary even when originating from the same parents. This is especially true of those grown from seeds. Plants from cuttings will be more like the parent plant.

Q. I was put on a diet and it included potatoes. Aren't they supposed to be fattening?

A. the fact is, a medium-sized potato is surprisingly low in calories -- about 90, the same as an apple or banana.

Q. Can you tell me the best way to control iris borers? They have almost wiped out my prize iris bed.

A. The adult iris borer is a moth that emerges in late summer. In the fall, it lays up to a thousand eggs on roughened or crinkled surfaces of the oldest bleached and twisted iris leaves, or on other plant material nearby. At first, the eggs are creamy white with a greenish tinge. They soon turn pink and finally become lavender in color.

The best control is to clean up all rubbish and old plant material before the eggs hatch in early spring. The tiny caterpillars crawl up the iris leaves and bury themselves inside the leaves and eat their way downward to the roots. Check your plants in late April and again in early May: Crush the young caterpillars, if any, by pressing the water-soaked parts of the leaf between thumb and forefinger. Spraying the leaves with Sevin about the time the eggs hatch also should control the borer.