LILACS

GARDEN PATCH POINTERS
By Robert and Hoberley Schuler

LILACS

Q: I purchased two lilac bushes from the Descanso Gardens 2 ½ years ago which are supposed to tolerate summer heat. They are doing OK, but do not produce many blooms. What should I do throughout the year to promote better growth/blooms? Violet, Redlands

A: Lilacs, Syringa vulgaris, is the common lilac found in cold weather locations. After the spring leaves have formed, big clusters of fragrant flowers appear at the branch tips. There are many varieties of lilacs, but most do not bloom well in hot valley conditions, but can be beautiful grown on upper slopes where the winter chill is adequate. Plant in full sun or partial shade in well drained slightly alkaline soil, composed of decomposed granite and/or clay. If your soil is strongly acid, dig lime into the hole before planting.

To get more blossoms, you can try to force dormancy on an older bush by withholding water from September until January. If the rains have not soaked the soil, water once a week. I have tried ice cubes placed at the base of the bush in December and January to encourage plants to bloom. There are other lilacs varieties hybridized for your area that do bloom more like those “back East”.

Pruning is best done after the flowers are spent or picked in the spring. Pinch back tips on younger plants with overlong stems. Remove the blossoms back to a pair of leaves; growth buds at that point will make new stems for next year’s flowers. Prune out some of the older stems each year to keep the shrub from becoming overgrown and in good flowering condition.

If you have a larger, older shrub, prune out some of the branches at the base which will stimulate new growth and force better branches for next year. You will not hurt the bush by removing this excess growth providing you do not prune below the graft. Powdery mildew can be a problem, but the plant needs the leaves for substance during our hot weather. Remove diseased leaves in the fall, but do not compost them.

Flowering lilacs for zones 18 and 19 include Descanso hybrids such as ‘Lavender Lady’, ’Sylvan Beauty’ and ‘White Angel’. My favorite for mild winters is Persian Lilac which grows to six feet and as wide and has many clusters of fragrant, pale violet flowers all along the arching branches. I also enjoy Syringa meyeri, Dwarf Korean Lilac which is ideal for small gardens or potted for the patio. Each individual flower is a tiny tube making up a cluster of lilac pink flowers. The plant likes your warm and mild climate.

Feed with a balanced fertilizer, such as 10. 10.10, when you see the leaf buds forming. Woody lilac stems have difficult time absorbing water in bouquets. They will absorb more water if the stems are broken off by hand or if you clip, crush the ends of the stems with pliers.

Lilacs can make a great hedge between neighbors. They do not grow too tall, have nice foliage on both sides, can bloom and yet when they go dormant they still make a nice fence that you can see through.

Robert H. Schuler, M.G.
rhschuler@frontier.com

GARDEN PATCH POINTERS
By Robert and Hoberley Schuler
OREGON STATE UNIVERSITY Master Gardeners
National & CA Garden club CGCI
Garden Study and Landscape Design Master Consultants