It forces them to produce more new branches so they will have more flowers next year. Keep in mind that you may have to wait for flowers, as it takes about three years for them to develop once entire shrub has been cut. The following year, again in late winter, remove half of the old stems. Though commonly a plant for U.S. Department of Agriculture plant hardiness zones 3 through 7, where summers are warm and winters are cold, there are some lilac varieties that can be coaxed into regular blooming in the milder climate of USDA zone 8. They should be pruned as soon as they stop blooming in the spring so that you don't cut off next year's buds. Cut out any damaged or diseased stems. You should clip flowers off immediately after they fade, but even if it slipped your mind last year, some careful pruning can get you back on track for spring. Depending on the variety, lilacs are available in shades of purple, violet, pink, blue, magenta, white, and of course – lilac. Can I Cut Off Old Lilac Blooms From Last Year in Spring? Lilacs grow in U.S. Department of Agriculture plant hardiness zones 3 through 8, depending on the variety. Like other lilac varieties, its blooms also work well as cut flowers, keeping a vase stocked with fragrant blooms for months during the growing season. How to Prune Lilac Bushes Regular Maintenance Pruning. Yes, but it is better to trim the old blooms as soon as they turn completely brown (look dead). Retain several well-spaced, vigorous stems and remove all the others. Don’t wait too long, as next year’s blooms start forming in the summer. Begin the procedure by removing one-third of the large, old stems at ground level in late winter. Spring-flowering lilacs (Syringa spp.) Therefore as the bush gets older and older and puts out more and more new branches, since it blooms better on those newer branches, gradually the blooms are all way up high and unreachable to gather for bouquets. Then we lost the birch to borers last spring. You might want to cut off the dead blooms to tidy up the appearance of the shrub, but it will bloom next spring whether you do or you don't. Blooms can be sparse if your lilac consists primarily of aged old wood. Does Deadheading Roses Keep Rose Bushes Attractive? Southern Living: The Daily South -- Is the South Too Hot for Lilacs? Severe pruning encourages new growth but since lilacs flower only on old wood, it can take several years before the lilac blooms proficiently again after a severe pruning. Pruning is actually good for them. But whats the point if you want that lovely fragrance in … Cut back the old flowering tips too far in late winter or early spring, and you won't see any bloom for another year. The old flower cluster should be cut off at its base—just above the two new shoots that angle out from the stem that ended with the old flower. I get so many good memories of things, when I sniff smelly lilacs!! Also, thin out some of the new growth. No fix for that, aside from cutting trees, and I'm choosing the trees over bountiful blooms. You must deadhead the lilacs soon after they finish blooming so you don't accidentally remove the new buds and ruin next year's flower cycle. Lilacs flower in mid-spring, but the flower buds are produced in late spring or early summer soon after the old blooms die. Reed was editor of the "Grand Ledge Independent" weekly newspaper and a Capitol Hill reporter for the national newsletter "Corporate & Foundation Grants Alert." Lilac bushes SHOULD be cut, they are FOR being enjoyed where you want them in vases or being given away. remain in bloom for two weeks or longer, but they begin to produce ugly brown seed clusters as soon as the old blossoms wilt. There is a method to cut your lilacs that will be best for the bush and will give you fabulous cut flowers for your home or to give away. Trim them with bypass pruning shears, cutting blooms off just above the place the stem forks beneath the bloom. Patricia Hamilton Reed has written professionally since 1987. But the sooner, the better. It has one main trunk and several suckers that are a few years old. They all need to be cut down in order to give a clean look. Although lilacs will flower reliably even if you don't deadhead them, or remove the spent flowers, they look better if you trim them at the right time. If you save the task for later in the season, you risk pruning off next year’s blooms (because next year’s flower buds form on the current year’s wood)—a mistake I made in the past with an unruly forsythia! Pruning lilacs is best done within a few weeks after the blooms fade. Removing the dead flowers from your lilac bush will encourage more blooms the following year. The lilac grows naturally as a bush but can be trained and shaped to grow like a small tree. I may put a lilac in a different location to have more. 2... Rejuvenation Pruning. Jenny Harrington has been a freelance writer since 2006. Cut off the old dead flowers as soon as they begin to turn brown and wither. Your lilacs will thank you with more abundant bloom, because removing old flowers lets the plant put more energy into setting next year's buds rather than forming seeds. Lilac bushes should be pruned and maintained each year. Lilacs are shrubs that bloom on old wood. How to Trim Lilac, Rose of Sharon and Forsythia Bushes, Iowa State University Extension: Yard and Garden: Lilacs, Cornell Cooperative Extension: Growing Lilacs. Your Lilac Bush is Still Too Young to Produce Blooms If you planted a lilac bare root, then you’ll need to be patient! Cut off Flowers, Shoots, Suckers, and Runners: You would find the base of the lilac plant clumped with old and wilted flowers. The following year (again in late winter), prune out one-half of the remaining old stems. If the plant is too bushy, the inner leaves do not get enough sun and air circulation, an invitation to plant disease. A second way to prune old lilacs is to cut back the overgrown shrubs over a three-year period. The general shrub pruning rule is to cut no more than a third of the stems each year. Church flowers, nursing home friends, spread the flowers around! Come July, you risk cutting off next year's flowers. The entire flower head requires removal so it doesn't set unattractive seed clusters. Other Reasons Lilac Bush is Not Blooming Older lilacs can have stems as thick as small trees and will flower only on the topmost branches. Lilacs flower in mid-spring, but the flower buds are produced in late spring or early summer soon after the old blooms die. Whatever the variety, all bloom on last year's growth -- forming buds on shoots that develop over the summer after they bloom. To reinvigorate an older plant and to encourage more blooms, remove about one third of the plant each year by cutting the selected shoots and branches back at ground level. 2. Some people like a wide lilac bush while others prefer to keep their’s shorter and smaller in circumference. Perform a rejuvenation pruning on mature Japanese lilac trees every few years by cutting one-third of the large, old stems all the way back to the ground in late winter. The plants should be full looking, yet not overly bushy. Pruning in the winter will remove all the bloom for the following spring. If you cut a bouquet of lilacs when they're in bloom, you have pruned the tree. Pruning needs to be a bit more circumspect if summer passed you by without tackling your lilac. I have noticed that when I cut my blooms off my lilac bushes for bouquets, the bush doens't flower as heartily the following year. You would also see many branches, runners, and suckers overgrowing in all directions. The rule of thumb, however, is to cut off each dead bloom and its INDIVIDUAL flower stem, which is referred to as “old wood”. Make pruning cuts 1/4 inch above the topmost leaf set, just beneath the old flower cluster. The good news is that it's easy to avoid cutting out shoots that are about to bloom -- they emerge from the base of the shoot that bloomed last year and should have a cluster of tiny buds at the tips. Lilac flowers bloom on the 1-year-old branches. It can be an important step to lilac recovery if winter damage has occurred. Old growth should also be cut back every few years to help keep the bush productive. Lilac flowers should be cut and enjoyed but many people are afraid that they might ruin their bushes if they start hacking away at them. That means fewer blooms. If you wait too long, you risk removing some of the next season's blooms. You may need to do a rejuvenation pruning of an older lilac and wait two or three years to let it come back to full bloom. You don’t want to cut them off by mistake. Ideally, you should remove one-third of the oldest, thickest stems to their base and cut each flowering tip back to a side shoot within a week or two of flowering.