For one to obtain the best results with lilacs you should consider the following:
Lilacs do best in full sun for at least 2/3 of a day.
They do not like wet feet. Plant in a well drained soil.
They like a sweet soil. pH 6.0 -7.0
They grow ideally in hardiness zones 2-5
Lilacs should not be planted too deep. The surface of the plants soil ball would be level with the surrounding ground. Dig a hole the same depth as the root ball plus a little wider to allow for straightening the plant. Back fill the gap with good soil, avoiding air pockets. Press the loose soil in firmly. Water it well.
All newly planted shrubs should receive a good watering 2 or 3 times per week for the first month. After the first month they should be watered deeply once a week. Most trees and shrubs require 1” of water per week during the growing season. The soil should be well watered before the ground freezes. Caution: do not overwater.
Do not fertilize the first year of planting. In early spring a fertilizer such as wood ash, well-aged cow manure or a 5-10-5 fertilizer can be applied.
Lilacs prefer a sweet soil, so a handful of lime spread around the base of the pant every year or two is recommended.
A few inches of mulch around the base of the plant will help to conserve moisture, to control weeds and to keep roots cooler. Always be sure to keep the mulch away from the base of the plant so air can circulate.
Pruning is optional. Dead heading of spent blooms can be done to improve the plants’ appearance. If you choose to pune, do so within 2 weeks following the current year’s bloom. This will allow the plant time to set next year’s flower buds.
Rejuvenating older plants
When rejuvenating older plants removal of up to 1/3 of the oldest stems each year is possible. The move new growth you can encourage, the more flowers you will have in the future.
Tagging and maintaining plant identity
Each of the lilacs in the Moore’s Hill Lilac Nursery has a unique identifying metal tag with the official cultivar name. To maintain this identity, you may leave the tag on the plant, making sue to inspect yearly so as to loosen and retie the tag as the plant grows. Or you may nail a tag inside on a garage wall.
Acknowledgement to Evie King of Syringa Plus Lilacs, Swanville, Maine for being a helpful resource in preparing this Care Guide.