How to Grow Lilacs in the Deep South
The mild winters in the South make growing most varieties of Lilac difficult, since Lilacs need a colder climate to flower well. The secret is to select a variety that does well despite the lack of freezing temperatures:
Aside from the lack of cold winters, the south’s acid soil also does not please the lovely lilac, that we transplanted Northerners miss longingly. But lilac lovers can still visit those fragrant panicles by growing varieties that do just fine in the heat and humidity. Syringa Vulgaris, whose common name is Lavender Lady, does quite well in the south, and it can be obtained by contacting Monrovia about it, (plant patent 1238). It has very fragrant albeit small flowers, and performs reliably with only modest care.
Lilacs are prone to powdery mildew here in the south, and spraying with garden fungicides may be necessary to control it. Baby shampoo and a gentle stream of hose water may be adequate for light cases where only a few leaves are affected. The mildew does little real harm, it’s just unsightly.
In order to get the best flowering, buy Lilac food from a grower who specializes in lilacs and feed regularly according to the directions. Water until bushes are established; if you are under watering restrictions, consider collecting rain for your lilac, to protect your investment. Grey water, containing soap or detergent is not nearly as good for lilacs as the fluoride and chlorine free stuff nature provides, and may actually harm them. Improve the soil with mushroom compost, organic material or rich soil, digging a hole 2 times larger than the root ball with sloping sides. Roots develop better in and push through loose soil more easily, so give them the edge they need to succeed. Our acid soil is not what the lilac prefers generally, so purchase non-acid soil specially formulated for them for spectacular results. Send your search engine after sources for growers, special lilac fertilizer and soil to make them happy.
Sight your lilac carefully, taking advantage of early morning sun which is cooler if possible, and less of the brutal mid-day sun. Too much shade will result in all vegetative growth and no flowers, so don’t be afraid to re-locate after a trial period, if you’re doing everything right and there are still no flowers. Do any shaping or pruning immediately after flowering, or there won’t be sufficient time for the lilac to set woody growth for new flower buds. I don’t prune at all some years and let the lovely bush develop naturally. I get loads of flowers with minimum care. In order to keep them looking tidy I mow the “suckers” or shoots that spread from the base or clip them with clean shears, and occasionally prune out old dead wood from the center.
Kew Gardens in England covers about 300 acres on the bank of the Thames river,and is a good place to enjoy lilacs, at these Royal Botanical Gardens. There are a number of lilac festivals in Indiana and Illinois where many varieties flourish, and they time them so that the bulk of them are in flower during the festival. Their wonderful scents invoke memories of cherished lilacs we enjoyed as children, left behind when we migrated south.
There are a few other varieties of Lilac that will flower in the south, a dwarf variety called “Miss Kim” which I found at Pike’s Nursery a few years ago,(S. Patula),the cut leaf variety Syringa Laciniata, Blue Boy, Blue Skies, Chiffon, and Forest K.Smith.