Q-In 1976 and 1977, my poinsetias bloomed beautifully at Christmas but in 1978 they were less than successful. Now much and when should they be fertilized? When should they be repotted? Is it crowding them too much to put two to four in one pot ?

A-In the spring cut back the stems to about four to six inches above the soil level. Then repot it, using a pot one or two sizes larger. Remove the root ball from the old container, shake off loose soil slightly, exposing root tips. Use a pre-mixed potting soil. Fertilize every three or four weeks with a liquid-soluble fertilizer, follow directions on the label.

By early July the plant has reached about half its season's growth. To control the shape and height of your plant, cutt off the terminal portions of the shoots between July 15 and August 1. This will give you a much shorter, bushier plant with more shoots at flower bud-setting time.

With two or more plants growing in one small container, they will compete with each other to the detriment of each one.

Q-I have heard that newspaper can be used to help fertilize plants. Is it true ?

A-Newspaper can be used to mulch plants but does not contribute to their nutrition. It is sometimes used along with other materials for making compost, but unless shred-ded there is considerable doubt about its value for this purpose. Even under ideal conditions cellulose (in the form of paper) is very resistant to the micro-organisms that break down the material.

Q-I have many beautiful little crocus plants. They multiply from year to year and now have just about taken over my garden.Can I dig the bulbs and separate and replant them as soon as the foliage dies down ?

A-As clumps of crocus increase and spread, division and replanting will increase the number and size of blooms. I usually needs to be done every third or fourth year. Do it immediately after the foliage dies down and replant the bulbs immediately. The same is true of snow flake, snow drop, winter aconite, wood hyacinth, glory-of-the-snow and grape hyacinth.

Q-We have an 18-month-old Irish setter that ruined the grass in our back yard last summer, even the crabgrass, by dashing around here and there.Is there a tough ground cover that will grow and take the punishment after it becomes established ?

A-Your best bet may be Kentucky 31 fescue. It's tough enough to hold up on playgrounds and on baseball and football fields, and it's used in Arlington National Cemetery where heavy foot traffic by tourists makes grass hard to grow.

Divide the yard into two sections. Confine the dog to one while you get the grass established in the other. Seed heavily, about eight pounds per thousand square feet. Allow about six months before turning the dog loose on it. Then do the other half.

One of the most important things with this kind of grass is to cut it high, at about 21/2 inches.

Q-Something is doing damage to the leave of my American holly. A specimen is enclosed. What can I do to prevent it ?

A-The specimens show spine spot. When leaves are punctured by spines of adjacent holly leaves, small graying spots with purpose borders occur.There are tiny holes in the centers of the spots. The only control is to prune off the leaves that can damage others when the wind blows them around.

Q-Is it too late in the season to sow bluegrass seed in the bare spots of our blawn ?

A-Bluegrass send may take three to four weeks to germinate, and there isn't time enough for the new grass to become established before hot weather. Wait and sow the see in late August.