Q: My mother would cut tulips and they'd last a week or longer. For me it's only a day or two. What's the secret? A: Here are some tips from Lisse Bulb Research Station, in The Netherlands: Cut the blooms when they have just acquired full color and no green shows. Get them into a vase of water as quickly as possible; the blooms should not be allowed to dry out. Temperatures below 68 degrees F. are important and 32 to 41 are best. By all means keep them in a cool place at night. And, putting sugar in the water may do more harm than good and changing water in the vase or adding disinfectants does not help. Q: I bought some Northern Spy cooking apples and saved the seeds to start my own orchard. Is is possible? A: Seeds of apples and other tree fruits do not produce plants similar to the parents. Usually they are inferior, but one in 5,000 may be quite good. If it's fruit you want, buy the plant and varieties you prefer. But Johnny Appleseed did it; maybe you can too. Q: A gardenia plant in full bloom was given to me at Easter three years ago. Since then the plant has had only two or three flowers, but beautiful green foliage. Do you know what's wrong? A: The gardenias sold as potted plants at Easter are forms of Gardenia veitchii. They develop flower buds only when the night temperature is below 65 degrees. Buds may form at 70 degrees but invariably drop off. If the night temperature goes below 60, plant growth may be retarded. Q: Why do my radishes all go to tops with no radishes in the soil? A: Sowing radishes too thick and not thinning them when they come up, or applying too much nitrogen fertilizer could result in poor roots. They should be spaced at least an inch apart to develop properly. Q: The last two years my azaleas have had few flowers on them; they seemed to go into winter with plenty of flower buds. What could be wrong? A: A few warm days in late winter can trigger early spring. The wounds heal quicker then than at any other time.Small twigs can be removed anytime. Unless there are structural weaknesses to correct, such as Y-crothches, wait as long as possible before removing the lower branches. The leaves produce the food of the plant and the removing leaves removes food producers. Q: I'm going to try to grow vegetables this year for the first time. Is it true that heavy use of fertilizer helps to prevent plant diseases? A: Just enough fertilizer will promote vigor and a vigorous plant is less likely to become infected. On the other hand, too much fertilizer can make the plant more susceptible to infection, because lush, soft growth is very susceptible. Q: Each year I plant a row of spinach and each year it goes to seed. What am I doing wrong? A: You are probably waiting too long to plant it. Spinach is a cool season crop and it will go to seed after the weather warms up. Q: I want to rehabilitate some neglected boxwood bushes one to two feet tall. How should I prune to encourage growth at the base? A: Cutting a stem back tends to stimulate new growth close to where the cut was made. Thus, new growth at the base may be accomplished by cutting the boxwood back 50 percent or more. Q: How do I keep a hydrangea pink? A: Hydrangea color is determined by the soil pH. Acid soil results in blue flowers, neutral or alkaline soil in pink ones. Your best bet is to have your soil tested and find out how much lime to apply to make it more alkaline. Q: When is the best time to plant asparagus? A: Early spring is the usual time, when garden centers have the roots available for sale and mail order places ship the roots. Q: I have a male aucuba and would like to root cuttings for my sister who has two female plants that have never borne berries. When is the best time to take them? A: Take the cuttings after growth starts in the spring, each 9 to 12 inches. They root readily in water. When roots are about an inch long take them out of water and pot in soil. Once the roots are established in soil, plant them in the ground near the females. Q: What kind of flowers can be grown in shade? A: Impatiens, wax begonias and coleus are the most successful flowering annuals for a wide range of shade conditions -- almost anything but deep shade and dry shade. Hybridizing has greatly improved impatiens and wax begonias, and coleus comes in a brilliant range of foliage colors, including pink, red, yellow, lime green and orange. Q: We have English ivy growing up the trunk of a sugar maple. Will it harm the tree? A: The ivy will not hurt the tree unless it gets so thick at the top that the leaves are shaded. That would reduce food production and over a period of years could weaken the tree. On the other hand, after the ivy has been shading the trunk for several years, its removal may cause serious damage to the tree from sunscald. The trunk would have to be adjusted gradually to the hot sun. Q: I planted seeds of Blue Lily of the Nile two years ago. Two of the plants are growing fine but have never bloomed. How do you make them bloom? A: Blue Lily of the Nile (Agapanthus africannus) also called Blue African Lily, started from seed usually does not bloom for three or four years. The plants are transferred to progressively larger pots until mature, when they require about a 24-inch tub. Q: Our firethorn is a fine big plant but has no red berries. Basically, what fertilizer gives blooms instead of foliage? A: Firethorn (Pyracantha) will not bloom in heavy shade or if it gets too much nitrogen fertilizer. Q: I have a shady place in the backyard where I planted petunias last year. They didn't do much. Is there something better I can plant? A: Coleus and impatiens both put on a good show in light to medium shade.