When I went to get the hose a few years back, I saw that my lilac bush had a ton of branches ripped off of it. I accused my poor hubby of using the pruners too aggressively. I quickly learned, though, that the mother squirrel who was painstakingly constructing her nest was responsible for the hack job. She would run to my chimney after tearing off one or two branches (but that’s another story entirely). The lilac has been thriving, which is comforting to me as I was concerned it wouldn’t return the next spring. One of my favorite springtime scents is lilac. When they are in bloom and swaying in the breeze as I work outside on my deck, I inhale deeply. Lilacs should be pruned once their fragrant blossoms have faded. I so decided to provide some advice!
Once the blooms have opened and faded, a lilac bush is ready for pruning. Shrubs that bloom in the spring should be clipped as soon as they finish blooming. Because flower buds for the following year develop on this year’s wood, delaying the task until later in the season runs the danger of removing next year’s blooms, as I did with an untamed forsythia in the past.
When should lilacs be deadheaded?
Lilacs should be deadheaded no later than 10 days after the flowers have faded, according to Cornell University Cooperative Extension, so that the shrub will focus its energy on developing new buds for the spring rather than seeds. In addition to depriving the shrub of energy, waiting too long to deadhead increases the likelihood that the new buds will be harmed or eliminated during the procedure.
Lilacs generate so many blooms that hand deadheading them might take too much time. The University of Minnesota Extension advises using a hedge trimmer to remove any wasted blossoms in that situation. Otherwise, you can also deadhead lilacs with pruning shears or strong scissors.
Cut back lilacs to the closest pair of leaves to deadhead them. Use your scissors or shears to cut the stem, then throw away the flower head. Although the Ohio State University Horticulture Extension cautions that deadheading Chinese lilacs (Syringa x chinensis) has only a minimal effect on their flowering and is normally too impractical to attempt even on younger bushes, deadheading generally improves the blooming of most lilac species. Chinese lilacs are occasionally grown in USDA plant hardiness zones 3 to 7, though they are less frequently cultivated than garden lilacs.
How are lilacs pruned to promote more blooming?
An old, overgrown lilac was one of the few plants that endured my garden restoration. The fact that it obscured my neighbor’s garage and, more importantly, sported steel-blue double flowers, led me to rescue it. Although the blossoms on this shrub were both lovely and fragrant, it was difficult to appreciate them because there were so few of them. I decided to go with a rejuvenation pruning because I knew there was no reason to give up on this long-neglected plant because lilacs can handle severe pruning.
On stems that are no older than five or six years, the common French lilacs (Syringa vulgaris cvs.) yield the most and the largest flowers. The flowers get fewer, smaller, and farther away as the stems get older. A lilac, however, may reliably produce blossoms for decades with the right trimming. The method you choose will depend on how old your shrub is. Plants are maintained annually to keep them healthy. A more drastic trimming may be necessary for lilacs like mine that have seen better days.
Lilacs should be clipped annually to encourage healthy stem development and strong growth that improves flowering. Cutting sick, deformed, and unproductive stems to the ground constitutes annual pruning. I thin and cut back some stems as well to promote healthy, evenly spaced growth. To prevent them from growing too far away from the center of the plant, I also pruned a few of the new shoots that emerged from the roots. I left a few inches between each stem to prevent crowding. Since they produce the most, I maintain the pencil-thick shoots that extend all the way to the ends of the branches. Small, twitchy growth is unproductive and won’t blossom. This growth can indicate an excess of aged, unproductive stems or too much shadow. Remove stems as soon as possible after blossoming, or in late winter if you don’t mind losing a few blooms. Cut off stems and shoots at or just below the soil line.
Dwarf lilacs rarely need pruning
Both the “Palibin” Meyer lilac (Syringa meyeri “Palibin”) and the “Miss Kim” Manchurian lilac (Syringa pubescens ssp. patula “Miss Kim”) are twiggy-habiting, somewhat small lilacs. On these types, just deadheading is needed in terms of pruning. You can prune some of the older stems as the plants get older to make place for younger, more robust stems. In contrast to regular lilacs, these plants hardly ever spread out of control. They might never need to be entirely regenerated if you only undertake a tiny amount of trimming every few years.
After the blooms have faded, deadheading, another aspect of annual maintenance, should be carried out as soon as feasible. Just above the two new shoots that slant out from the stem that stopped with the old bloom, the base of the old flower cluster should be cut off. The new shoots will develop throughout the course of the summer, produce flower buds, and culminate in a cluster of flowers the following spring. While not as crucial as the annual thinning, eliminating the old blossoms enables the plant to focus more of its energy on developing robust branches and flower buds. In June, I deadhead and thin my plants as needed.
While performing this yearly maintenance, I occasionally come upon a young, robust shoot that may be getting too tall but is still a good, productive stem and is a candidate for tipping off. I cut the wasted flower’s entire top stem back to one or two side shoots at the desired height rather of just cutting it off at the base. The side shoots that are now near the top of the bush are encouraged to grow vigorously and develop flower buds for the following year by this cut, which also aids in shrinking the shrub.
My own old, overgrown lilacs need more severe pruning. I went outside in the early spring before growth got going to get a good look at the bush. I looked to see if the plant had been grafted before I began chopping. I immediately cut it down to the ground as it hadn’t (for a grafted plant, see the panel below). I recognized that this drastic trimming would result in the plant losing part of its aesthetic appeal for a few years because lilacs bloom on the growth from the previous season. However, I was also aware that the reward—more blossoms and a stronger plant—would be worthwhile.
It’s crucial to nourish the plant after rejuvenation pruning with compost, composted manure, or a balanced chemical fertilizer and to make sure the soil pH is close to neutral, which lilacs appreciate. In the upcoming years, these supplements and some high-quality mulch will help to encourage vigorous new growth and enhanced flowering.
Has your lilac been grafted?
If your lilac has been grafted, check it out before you start making cuts to the stems. Grafting is a method of plant multiplication in which the scion, or branch, of one species is joined to the rootstock, or stem, of another species. This is typically done to enhance a plant’s look or traits. A graft union, where the cultivar’s scion wood joins the rootstock several inches above ground level, should be obvious. An apparent change in the bark from the rootstock to the scion’s bark, as well as a little swelling at the graft union, are things to watch for. If your plant has been grafted, all of your cuttings must be made above the graft union, and you must prevent shoots from the rootstock from developing into new flowering stems. Flowers of the desired shape or color will not be produced by shoots that emerge from the rootstock.
Should I prune my lilac’s dead flowers?
Your lilac bush will produce more blossoms the following year if you remove the dead flowers. When cutting off your flowers, it’s crucial to only remove the wasted blooms—don’t worry about any nearby stalks. Simply concentrate on the spent bloom’s stem if you can see the two fresh shoots that will grow into blooms the following year. Avoid cutting off the blossoms for the following year!
I now wish to stimulate a second flowering on my dwarf Bloomerang, which ought to happen in late summer or early fall. In order to produce more new growth and blooms during the second bloom season, the spent spring blossoms should be pruned off. A small amount of fertilizer made specifically for woody plants, which I could also use, will help encourage the shrub to bloom once more.
Which month should lilac bushes be pruned?
All lilacs should generally be clipped right away in the spring after they have finished blooming. Lilacs set their flower buds for the following year immediately after the current year’s flowers have faded, therefore trimming later in the summer or fall will result in the removal of most or all of the blossoms for the following year. The larger common lilacs as well as the shorter or more “shrub like” cultivars are all subject to this timing guideline. While the “when” of lilac trimming is rather simple, the “how” is a little more difficult. For the time being, we’ll refer to lilac pruning as either maintenance pruning or rejuvenation pruning to keep things simple.
What happens to lilacs once they bloom?
A lilac shrub needs to be pruned every year once it has reached the age of two. Early summer is ideal for cutting grass because the flowers have already flowered and withered. Here are some tips for taking care of lilac shrubs and trees.
Lilacs produce the flower buds for the following season in the early summer, right after their blooms have faded. You run the danger of removing the budding buds if you delay trimming until later in the growing season.
This also holds true for lilacs that bloom twice a year, like Bloomerang Purple. After the bush’s initial bloom, you can prune it to promote new growth and more flowers in the second bloom, which occurs in early fall.
Lilacs eventually only bloom at the tips of their highest branches if allowed to develop naturally. Lilac bushes can be revitalized and made more visually appealing by pruning to maintain a balance between older stems and young blossoming branches.
Pruning a lilac shrub involves a number of techniques:
- First, remove any weaker branches and any dead, broken, or diseased stems. Branches should also be trimmed to avoid rubbing or crossing.
- Old stems that are thicker than two inches should be cut off. This controls the height of your lilac plant and promotes the development of new shoots. It is best to thoroughly remove the stems.
- Control sucker emergence. Suckers are fresh branches that sprout from the plant’s base. The main branches can be replaced by a few robust suckers, but any lesser suckers should be removed at the soil line to prevent them from robbing the plant of nutrients.
Last but not least, here are some general guidelines for pruning lilacs:
- Lilac bushes that are mature should only be pruned to a height of 6 to 8 feet.
- Aim for 10 to 12 primary stems, each of which should be between 1 and 2 inches thick.
- Never remove more than one-third of the bush with pruning.
- Older stems and fresh blossoming shoots should be balanced.
Do I need to remove the lilac seed pods?
Did you know that lilacs can live for 350 years or longer? The earliest lilacs still growing in America were planted on Michigan’s Mackinac Island by French missionaries in 1650.
In addition to having a long lifespan, lilacs are also incredibly resilient, grow swiftly, and have a wonderful aroma. Observe the lilacs that are blooming and have been blooming for many years on Richmond Road in Historic Richmond Town. Since lilac bushes can live for hundreds of years, one that was planted during the time of George Washington and Thomas Jefferson may still be present. There are no other flowers as lovely and fragrant as lilacs besides roses. Lilacs actually have a perfume that is stronger and travels farther than that of roses.
Lilacs can be solitary or double, and they can bloom for several weeks. They can come in a range of hues, including violet, red, blue, pink, lilac, purple, yellow, and white. Grow a range of lilacs, including early, mid, and late kinds, to extend their bloom period. Lilacs can bloom in your garden in this way for up to six weeks.
How long blooms last is greatly influenced by the weather. It is best to have a chilly, dry period after the buds start to open. Although they are simple to grow, lilacs require full sun to bloom. For good airflow, leave lots of room around your lilac.
The common lilac that can be found in gardens is Syringa vulgaris. The hollow lilac wood, which is used to build flutes, is where the Greek term “syrinx,” which means “flute,” originated. Lilacs were first cultivated in Asia and Europe, with Asia producing the majority of the wild variety. Lavanders arrived in Europe via the Balkans, France, and Turkey.
The cut-leaf lilac is a small shrub of 7 feet or less with pale lilac flowers and finely cut leaves that is mildew resistant, as opposed to the early Korean lilac, which is rather tall and has huge, fragrant lilac-pink blooms. French lilacs are a classic garden delight that have a strong scent.
The semi-dwarf lilac “Fairy Dust” has small, 4-5 foot tall foliage and produces soft pink blooms that irregularly appear throughout the summer. For tiny gardens or a big container, “Prarie Petite,” a very little floriferous dwarf, is perfect. The unusual yellow-flowered lilac is called “Primrose.”
Lilacs prefer a soil that is neutral in pH, light, rich, and well-drained. You’ll need to add some lime if your soil has a tendency to be acidic. It is welcomed to apply a top-dressing of mulch, ideally well-composted manure, once a year. During the first season, remove buds and water frequently. After transplanting, they require a year or two to reestablish, so make sure the roots are never let to dry up.
Prior to pruning, let your lilac get well established. At the plant’s base, cut the oldest stems and allow a few new suckers to emerge in their place. Each year, you can remove a few old stems up to 4 inches from the ground. Before the buds swell in the early spring, severe pruning can be performed. You can prune your lilacs less severely if you hold off until after they bloom. Your lilac will grow more vigorously if you prune the oldest branches.
To ensure new blooms the following spring, carefully pinch off spent flowers up to the first set of leaves. This will prevent seeds from settling. Lilac tree pruning occurs when you cut a bouquet of blooming lilacs. Instead of cutting the blossoms and savoring their beautiful aroma, Lilacs produce huge seed-pods after their flowers have faded that also deplete the plant’s energy. After July 4th, refrain from pruning to avoid decreasing the show the following year.
Fill a container with warm water that has been treated with a floral preservative to make a lovely lilac bouquet. Early in the morning or late at night, cut the stems at a sharp angle and choose flowers with about 3/4 of the buds open. Remove the entire stem’s foliage to expose the flowers exclusively. Immediately put the cut end in the prepared container. Cut separate stems with no flowers on them if you’d rather have lilac foliage in your arrangement.
Lilacs are perennial favorites among gardeners, despite the fact that the majority of them lack grace and many are vulnerable to mildew in the late summer. I just couldn’t image not having at least one lilac in my garden after growing up with one in the corner of our yard and enjoying the amazing aroma of the blossoms every spring.
The Great Kills Garden Club’s former president and a former director of the First District Federated Garden Clubs of New York State is Lee Gugliada.
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