May 2018

Keep Your Lilacs Blooming for Years

Author Urban Tree

Purple LilacsOne of the great things about New England in the spring is when the lilacs bloom in May. Not only does the area burst with color ranging from the familiar purple to white or even reddish-pink, but they turn the entire region into a virtual Yankee Candle store. No wonder it’s New Hampshire’s State Flower. Best of all, lilacs are very hardy and following a pretty simple pruning routine may help ensure decades of enjoyment.

Lilacs can survive without pruning, but regular pruning will greatly increase the number and size of the flowers. It’s important to be sensible in your pruning however, because while blooms occur on old wood, most of the largest and most fragrant flowers bloom on stems that are less than 5 years old. As a rule of thumb, if you notice smaller flower clusters in an area, that’s a good place to prune.

The first step in pruning is to “deadhead” or remove spent blooms back to the base of the cluster immediately after the flower fades. This will allow the plant to grow new shoots over the summer and set a new bloom for the spring. Clearing out shoots at the bottom of the main stems as well as small, twiggy growth in the main bush will allow for better light and air circulation among the most productive branches. Branches that are about as thick as a pencil tend to be the most productive.

Next you want to remove any dead, diseased or unproductive stems in the bush. If you have an older lilac, cutting up to 1/3 of the oldest stems down to the ground with will help the younger, more productive stems thrive and keep your lilac vibrant. It’s amazing how resilient lilacs are, because this can turn even the most overgrown plant into a beautiful spring bloomer.