How Fast Do Peacock French Hybrid Lilacs Grow?

Environmental Influence on Growth Rate

• Climate has the greatest effect on how quickly “Peacock” French lilacs grow. They grow more quickly in warmer climates within their USDA zone. Day and night temperature differences also affect how quickly they grow. Maximum growth rate occurs when temperatures during the day are 10 to 15 degrees Fahrenheit higher than night temperatures. Growing conditions will influence the “Peacock” French lilac’s growth rate in all climates. For maximum growth, they require full sun exposure and fast-draining soil with a neutral to alkaline pH of 7 or above. In acidic soils, they might not be able to absorb nutrients. In soil that drains too slowly, the roots stay wet for too long and may be deprived of oxygen. This will not only reduce the lilac’s growth rate, it can cause it to develop root rot which will usually kill the shrub.

“Peacock” Growth Rate in Warm Climates

• In warmer climates, “Peacock” French lilacs can grow as quickly as 2 feet per year. This is simply because the shrub has a longer growing season. In areas within USDA zone 9 and above where winters are very mild, the lilacs might survive and grow but will not bloom. They require at least a week or two of cold frosty or snowy nights in order to set flower buds and bloom the following spring.

“Peacock” Growth Rate in Cold Climates

• In cooler climates with shorter growing seasons, the “Peacock” French lilac might grow only 1 foot per year. This is commonly the case in USDA growing zones 4 to 6 or 7. It is not necessarily growing more slowly, the lilac just does not have as much time to grow each year between later springs and earlier falls. It will also bloom later in the spring in cooler climates, because flowering is triggered when temperatures rise in the spring.

Maximizing “Peacock” Growth Rate

• Plant “Peacock” in fast-draining soil and give it 1 to 2 gallons of water every day or two for the first month, then 2 to 3 gallons twice weekly during the first three growing seasons. This is crucial for good establishment and quick growth. From the fourth year on, give it 5 gallons of water every two weeks in the spring and once per week in the summer. Do not water the lilac during the winter in mild-winter climates unless there is no rain for one month. Give it a balanced 10-10-10 fertilizer in late fall or early winter one month after the first hard frost to maximize its growth rate. The usual rate of application is 1 tablespoon per inch of shrub height but this varies depending on the fertilizer formula. Prune the lilac every spring immediately after it finishes blooming, trimming all the branches back by 20 to 40 percent. This encourages a healthier, more compact shrub that will produce its showy, fragrant blooms at nose height. Clean the pruners and disinfect them with household disinfectant after each use.