How to Grow Aromatic Lilacs (Syringas)

There are few things as sweetly scented as a fresh bouquet of lilacs. For many people, this aroma is also rich in childhood memories. It seems almost everyone's mother or grandmother had one these delightful old-fashioned shrubs a few decades ago. The blossoms of the deciduous lilac shrub are almost as beautiful as they are fragrant. They have one of the strongest scents of all flowers and the aroma can almost overwhelm a small room. The scent can also travel through the air for quite some distance whether inside the home or outdoors.

Lilac shrubs typically only bloom for a couple of weeks each spring, but it's still possible to have lilacs blooming for much longer in the garden. There are many cultivars available with variances in bloom times. Lilacs have early, middle and late blooming varieties. Choosing shrubs from each category can extend the flowers for about six weeks. It also requires patience for those first blooms to emerge. A young lilac can take up to three years to start blooming.

Attributes

Lilacs come in a wide range of colors, sizes and types of blooms. There are actually more than one thousand varieties of lilacs. The most common color is the well-known lavender, but they're also available in white, pink, dark pink, blue and purple. Lilac blooms also come in single or double petals. There are dwarf varieties of lilac shrubs that grow about 4-feet tall and others up to thirty feet tall. Most of these shrubs grow in the midrange of just slightly over 10-feet tall. Be sure to know the cultivar you're getting so it can be planted in the proper location.

Lilacs are low maintenance, but with a little care and the proper pruning they can last well past our lifetimes. The tall varieties can even provide quite a lot of shade in the summer. Several planted together can be used as a hedgerow to provide privacy. Of course, lilacs are best loved for their incredibly sweet aroma. They are a common ingredient for perfumes, soaps and home fragrances.

For the short time the lilacs are blooming, enjoy them in your home. Choose flowers on the shrub that have the small individual blossoms almost open. Cut several inches below the flower and remove most or all of the leaves from the stem. Try to cut an even quantity of flower stems from all sides of the shrub.

Check carefully for ants and other insects that are attracted to the sweet nectar before bringing them indoors. Lilacs look best when massed together in a large vase. Keep the lilac flowers out of direct sunlight and in a cool area to extend the life of the blossoms. Don't forget to keep the vase filled with fresh water.

USDA Zones

The many cultivars available also have different USDA Zone requirements. Lilacs are cold hardy and most will not do well in warm climates, although a few cultivars have been developed for southern zones. With this being said, it's easy to see the importance of knowing exactly what type of lilac you're getting. Plant labels with cultivars and USDA Zone requirements clearly listed are essential.

Don't be surprised at the variances of zones listed for lilacs. Some will be listed as hardy in USDA Zones 2 to 8 or Zone 1 to 7a or 7b. It is also possible to find the zones listed as USDA Zones 3 to 8 as well. Several varieties might be listed as hardy to USDA Zones 4 to 6, while the few southern varieties will be USDA Zones 9 to10. This may sound a bit confusing, but just remember that the zones will vary with the cultivars.

Requirementsand Care

Lilacs need good drainage and plenty of sun. They will tolerate almost any soil type except soggy. Lilacs can grow in sandy to clay soils but they can't tolerate being in a lowland condition where the soil stays wet. In their natural environment, they would grow on a hillside or elevated areas of land where poor drainage is never an issue. This is where they perform best. Lilacs will grow fine on level ground as long as the drainage is adequate.

This doesn't indicate that lilacs can withstand long periods of drought. They may occasionally need to be watered during dry spells. The lilac's roots eventually grow very deep so they will need to be watered correctly if this becomes necessary. This means a long and deep soaking for the lilac to reap any benefits.

The appearance of the area surrounding the lilacs will be improved if kept weed-free and mulched. Even though lilacs are not very particular about their soil, it's always beneficial to add organic amendments. They prefer a soil pH of 6 to 7 with compost and humus worked into the soil around the shrub. When fertilizing lilacs, it's best to use an all-purpose type with a high phosphorous content to increase flowers. Too much nitrogen in a fertilizer will decrease the quantity of blooms. Fertilize in early spring and then again after flowering has stopped.

Proper Pruning

The lilac bush will be more attractive if pruned a little each year. There are definite pruning techniques that need to be followed, or there may not be any blossoms to enjoy. Yearly pruning of all lilac varieties will improve the shape and also the health, vigor and flower production.

Only prune lilacs immediately after they've finished blooming. This includes removing the faded blossoms. This keeps the shrub from setting seeds and helps promote more blossoms the next year. A lilac shrub should have a full appearance but not overly thick and bushy. If the plant if too bushy, the inner leaves will not get adequate sun or ventilation.

Prune out the larger stems from the center of the shrub to increase air circulation. This will also encourage new shoots to develop on the outer perimeter of the plant. Sometimes small suckers or new growth will appear at or near ground level. These can be trimmed away. It's fine to leave a few strong new stems each year, especially if old wood is going to be pruned out. Always prune off any branches that are not attractive or distract from the shape of the bush.

The overall shape of the shrub should be the owner's preference. The general agreement from all lilac growers is to keep the top rounded. Lilacs look best with a natural shape and shouldn't be pruned into a flat-topped straight line. Other than that, feel free to allow the lilac to grow as wide and as tall as you want. Allow more side shoots to grow if a wider shrub is preferred. Lilacs are sometimes even pruned into a tree form with bare branches at the bottom. This is especially attractive way to prune the tall lilacs.

Lilac Problems

Lilacs are generally hardy shrubs and are seldom bothered by insects. Their worst enemy is a lilac borer. The bark is also a popular snack for hungry moles and mice during harsh winters. They eat on the trunk of the lilac near ground level which can cause fatal injury to the shrub.

Lilacs can be susceptible to powdery mildew during hot and humid weather. It's always better to control mildew as soon as it starts. Trim off the infected leaves at the start before it spreads. There are fungicides on the market, but organic methods are always safer for the environment.

Lilac History

The largest selection of lilacs can be found in the city dubbed the "Lilac Capital of the World." In fact, Rochester, New York has the largest collection in one location with more than 500 varieties planted. Horticulturist John Dunbar began the city's love affair with lilacs in 1892 when he planted about 20 varieties on a southern slope of the Highland Park. Rochester hosts an annual lilac festival in Highland Park which currently has more than 1,200 lilac bushes on 155 acres. The lilac was officially named New York's state bush in 2006.

Lilacs originate in the southern peninsula and eastern regions of Europe. There are also many varieties of Asian lilacs. The lilac history in the United States dates back to the mid 1750's. They were popular in New England and were grown in the first botanical gardens in America. George Washington and Thomas Jefferson had lilacs growing in their gardens. Lilacs can live for such a long time that some of those original lilacs could actually still be alive. They can live for hundreds of years just as many trees can.