Cutting off the tops of stems that have grown out of control is frequently insufficient when pruning lilacs. It is typically preferable to remove the entire stem. The best way to trim lilacs is with clippers. To avoid spreading and promote later blooms, remove spent blossoms right down to the stems. Three-quarters of the branches should be pruned. Remove any shoots that are emerging from the main trunk and are growing close to the ground. Lilacs within the inner branches may need to be trimmed in order to increase air flow or let more light through.
However, it may be essential to prune the entire bush or tree to approximately 6 or 8 inches (15-20 cm) above the ground if lilac shrubs are already too big or starting to look unpleasant. Remember that it takes around three years for flowers to grow after the entire bush has been removed, so you might have to wait.
When should you prune a lilac bush?
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.
How much should lilac bushes be pruned?
Never remove more than one-third of a shrub’s stems in a single pruning season for lilacs. I just cut the branches of the lilac tree down to a manageable height when they started to stray too close to the eaves. After trimming the dead blossoms, I decided to call it a day. A little minor thinning might also be done to promote new growth.
In late winter or early spring, a more vigorous pruning should be performed, perhaps on older shrubs that haven’t been routinely tended to. At this time, you should remove any old wood and damaged stems while keeping the more recent growth. Reduce the aging stems to the ground.
I’ll simply cut any very long sections off the Bloomerang lilac to keep the shrub’s form. Because bloomerangs naturally have a spherical habit, you don’t need to bother about sculpting the bush too much. My plant has been in the garden for a while and is still adorable and manageable.
Can you trim back lilacs to the ground?
The lilac tree will resemble nothing more than a twig in the garden by the end of September. It shouldn’t be reduced to the ground, though. Despite the fact that lilac trees are known for their resilience, it will likely take several years before you see blossoms again because you cut off all the blossoming growth.
If your lilac tree is more mature and unruly, it may require more aggressive pruning and some chopping back; just make sure that it doesn’t take up more than a third of the tree.
Should lilacs be Deadheaded?
The removal of spent flowers to encourage new blooming—deadheading—is a crucial part of lilac maintenance. Lilacs should be deadheaded as soon as the flowering is finished to allow the plants to grow robust, healthy buds that will flower vivaciously the following year. According to the University of Minnesota Extension, you can use a hand pruner, but larger plants could require a hedge trimmer. Only the dead blossom should be removed; the plant should still have two leaves.
According to the Chicago Botanic Garden, you should prune lilacs at the same time as you deadhead them since they set the blossoms for the following year quickly after flowering. By doing this, you can prevent damaging or removing the developing buds. Three to four years after planting, you should start pruning lilacs. It might be necessary to trim back overgrown lilacs to just a few inches above the ground. Winter is the ideal time to complete this. In this instance, it will take the shrub one or two growing seasons to start blooming once more.
Does new or old wood produce lilac blooms?
What specifically prevents these traditional plants from blooming? Instead of focusing on just one theory, consider a number of potential causes for this issue, including (in addition to illnesses and pests):
- Pruning when it’s not necessary
- The flower buds die in the cold
- placing your lilacs in the incorrect location
- The shrub in question either isn’t old enough to generate flower buds or is too old to do so.
You’ll see that while reasons one and three point to the gardener having done something incorrect, arguments two and four point to no one having done anything incorrect.
Why does it matter what time of day you prune? Shrubs called lilacs produce flowers on rotting wood. This indicates that the flower buds for the upcoming spring’s blooming season have already been formed on the growth from the previous year. When this growth is pruned, the flower buds and, consequently, the blooms they would have produced, are lost. Because of this, it is recommended that you clip lilac bushes as soon as they finish flowering (before they have set bud for next year).
Click Play to Learn How to Prune Lilacs
Despite being a relatively cold-hardy plant, the common lilac (Syringa vulgaris) can suffer harm if a hard frost or freeze occurs just as the flower buds are about to open. As a result, that year’s flowers are lost. You can’t really stop it, so simply accept the loss and look forward to the blossoming twice as much the next year.
Where you put your lilac shrub matters a lot, just like it does with most other plants. Lilacs require full sunlight and prefer well-drained soil. If you made a mistake when you first put your plants on either of these fronts, you can be paying for it today by your lilac not blooming. However, there is a simple solution to the issue: move your shrub to a more favorable location.
Regarding the fourth reason, be aware that although though these bushes have a long lifespan, they do tend to produce fewer flowers as time passes. Implementing a rejuvenation pruning on your lilacs will solve this issue (do not expect immediate results, though). Sometimes, though, the converse is true: your plant may be too young to bloom. Allow some time.
Can lilacs be pruned to preserve a small size?
One of the joys of spring is the luscious aroma of lilacs. The lilac bush, which blooms in late April or early May with clusters of tiny purple flowers resembling bunches of grapes, is a common sight in most communities.
These are primarily common lilac shrubs (Syringa vulgaris). Kris Bachtell, vice president of collections at the Morton Arboretum in Lisle, described it as “grandma’s lilac.” It is widely known.
He said that there are hundreds of cultivated types. Although there are cultivars with magenta, pink, and white blooms as well, the majority bloom in hues of purple. They are all resilient and enduring.
Despite being widely cultivated, common lilac is difficult for some gardeners to grow. Even if some newer types are more resistant to powdery mildew, older ones are frequently deformed by it in the late summer.
The plants, which are native to rocky Balkan hillside soil, require full light and well-drained soil. An older lilac’s blooming cycle may end if nearby trees have grown to shade it.
Lilacs require frequent renewal trimming to reduce their size and thin them out. According to Bachtell, this necessitates the yearly removal of certain elder stems as well as dead wood. Lilacs also frequently sprout suckers from their root systems, which may need to be cut back.
The common lilac can simply be too much of a shrub for smaller yards because it is a large shrub or small tree that grows 8 to 20 feet tall and almost as wide.
Fortunately, Bachtell says, there are alternatives. “He said that several other lilac species are somewhat smaller. “They might be more disease- and shade-tolerant than grandma’s.
Meyer lilacs (Syringa meyeri) can reach heights and widths of 6 to 8 feet. Even though it thrives in direct sunlight, it can tolerate some shade. The flower clusters are smaller but very fragrant, and they emerge a little later than those of the common lilac. Autumn causes the leaves to become yellow. Although there are various cultivars, Palibin is the most popular.
One cultivar, Miss Kim, of the Manchurian lilac (Syringa patula), is primarily recognized. On a plant that is 5 to 8 feet tall, it bears delightfully scented light purple blossoms that turn light pink as they age. In the fall, the ruffled leaves become purple-red. Compared to other garden lilacs, the plant is a little more resistant to powdery mildew.
Hybrid lilacs that rebloom in the late summer or early fall do so less profusely than they do in the spring. Bloomerang Purple (Syringa ‘Penda’), Bloomerang Dark Purple (Syringa x ‘SMSJBP7’), and Bloomerang Dwarf Pink (Syringa x ‘SMNJRPI’) are just a few cultivars in the Bloomerang line. They are all smaller than typical lilacs, although cultivar differences in size should be noted on the label.
According to Bachtell, pruning should be done in the first week or two after the spring shrub has stopped flowering if it’s necessary to keep a lilac untangled and at the right size. Pruning in the winter will destroy buds that might otherwise develop fragrant blooms since lilacs bloom from buds that were formed the previous year.
What distinguishes a lilac bush from a lilac tree?
Lilac bushes (also known as shrubs) are characterized by their numerous woody stems that emerge from the plant’s base. In contrast, the trunk of the majority of lilac trees is the only woody stem. However, your neighborhood garden center might also sell shrub lilacs that have been grafted onto a single stem to give them the appearance of miniature trees.
The choice between a lilac tree and a lilac bush is typically determined by the amount of space available. Lilac bushes come in a range of sizes and can be placed in more compact areas of a garden. A lilac tree requires space to reach heights of 20 feet and widths of 15 feet. Both require sunlight to bloom well.
Can a hedge trimmer be used to prune lilacs?
One of the most crucial aspects of pruning lilac shrubs is timing. One of your must-do gardening activities should be annual pruning after your bush is 6 feet tall.
Fortunately, knowing when to prune lilacs is not difficult to master—you are essentially deadheading the blossoms once they have finished blooming.
Lilacs should always be pruned as soon as their flowers turn brown because this indicates that they are finished for the season and must now begin preparing for next year’s display.
The quickest approach to determine this is by rapidly examining the color and texture of the blooms: have they lost their color?
Do they appear browning? Do they have a crunchy texture to the touch? Your lilac bush is finished blooming if you indicated yes in your response.
The flowers won’t appear as brilliant as they did when they first began to bloom. For instance, this lilac bush is still in bloom.
It’s challenging to generalize blooming times for lilacs because there are literally hundreds of different types and hybrids.
One such hybrid is the “Lavender Lady variety,” which can be cultivated successfully in zone 9 (yes, that’s you, So-Cal! ), and has an earlier bloom time than lilacs that are planted in colder zones. These hybrids have been developed to thrive in regions with warmer winters.
Variety is essential since some plants bloom early (early May, or even earlier in warmer climates), while others bloom later (late May to early June).
When it comes time to prune lilacs, you must maintain a close check on your shrub.
You’ll know it’s time to work on your shrub with pruning shears when you notice brown blossoms on it (I like these shears because they’re affordable, effective, and have thousands of 5-star ratings on Amazon).
What To Avoid When Pruning Lilacs
The biggest error you can do when trimming a lilac bush is to remove any new wood, as this is where your plant will develop its blossoms for the following year.
Your lilac bush won’t produce any flower clusters for you the next year if you remove any branches that aren’t completely gone.
Lilac bushes should be pruned with a round shape rather than a flat top, thus using a hedge trimmer to shape them could accidentally chop off the blossoms that will form for the next year.