Planting a windbreak; watering African violets from top and bottom

Q. Is it practical to start evergreens from seeds or cuttings? We would like a windbreak on the northwest side of our property, but large-size trees could be costly, since the expanse is more than 100 feet.

Starting evergreens takes time and know-how. More important, it takes from 10 to 14 years for them to reach an effective size. The first few years are slowest. Because a properly placed windbreak will save from 15 to 30 percent on your fuel bill, it's far more economical to buy established plants.

Nurseries have many sizes and usually give discounts on quantity orders. ''Heavy transplants,'' already five or six years old, well-shaped, and about 1 1 /2 feet tall, are a popular size. Ask the nurseryman to help with species selection, number needed, and distance calculations. The cost may be a pleasant surprise.

Q. When my daughter gave me a cyclamen in November, it was beautiful, but now it has stopped blooming, and the leaves are turning yellow. What should I do?

Let the plant get almost dry between waterings, and keep it at a cool temperature. As soon as spring frosts are over, set the plant outside in a shady spot. Repot the corm, setting it in an inch-larger pot and leaving one-third of it above the level of the soil.

Before frost in the fall, bring it into a cool, light spot in the house. Water sparingly until the buds start, then gradually increase water so the soil is constantly moist. At that time, give a half-strength feeding of balanced plant food, and feed again a month later. Cyclamen don't bloom well if they're overfed.

Q. I have just recently acquired several African violets. Do you recommend watering from the top or the bottom?

We do it both ways, but most often we water from the bottom. However, once every week or so we water from the top to flush down any fertilizer salts that may have risen to the top.

These usually appear as a whitish material on the surface of the soil. If the pots are of clay, it may show up on the rim and ''burn'' any leaf stems that touch it.

Firming a strip of foil over the rim will prevent stem damage. You can also dip the pot rims in paraffin before potting the plants.