Q - I planted lettuce seed in pots to grow on my windowsill this winter. That was three weeks ago and they haven't come up yet. Would it be because the seed were no good?

A - A common mistake when planting lettuce is to cover the seeds too deeply. They require light for germination. The seeds should be scattered on top of the soil and lightly scratched in. The soil should be kept moist until the seeds have germinated and become somewhat established, which takes two to three weeks.

Q - We can't grow grass, even crabgrass, in our backyard because of the dog that keeps dashing around, here and there. Is there a very tough ground cover that will survive with full morning sun?

A - Your best met may be Kentucky 31 fescue, a grass tough enough to hold up on playgrounds and on baseball and football fields.

Keep the dog off it until it becomes established. It usually takes about 10 days for the seed to germinate and less than a month to become well established.

Q - When is the proper time to fertilize young trees? Do you do it once in the spring or more? How about the fall?

A - The fertilizer should be applied regularly, preferably in the spring, just about the time growth begins. Or it can be put on in the fall after the trees have lost their leaves. Evergreens, however, should not be fertilized in late fall. Spring is the time to do it, up to late spring. Normally, once a year is ofen enough for both deciduous and evergreen trees.

Q - Should we break off the seeds of rhubarb?

A - Rhubarb seed stalks should be removed as soon as they form. The food that would be used in seed development can then be stored in the plant for production of a better harvest next year.