Question: When is the best time to plant lilac bushes? What fertilizer is best for them?
Answer: We have planted nursery-grown lilacs in every month that the ground wasn’t frozen. Spring, however, before the leaves pop out, is best. Fall (September through late October) is second best. Lilacs love manure, be it bagged or au natural; compost also is good, as is 5-10-5 fertilizer. Now and then, sprinkle a little lime or wood ashes around your plants because they appreciate near-neutral soil.
–Gardening experts George and Becky Lohmiller, Hancock, New Hampshire