How To Prune A French Lilac Bush

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.

French lilacs should be clipped when?

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 should an overgrown lilac bush be pruned?

Similar to the lilac, heavy pruning needs to be done over a number of years. Remove any dead, spindly, dying, or ill-looking wood first. At the base, remove roughly a third of the tallest, oldest branches. The remaining branches should then be cut back by at least a foot. Over the following two years, repeat the same action.

Azaleas and rhododendrons prefer somewhat acidic soils. The optimal time to fertilize in the spring is right after flowering. Though slightly more expensive than chemical fertilizers, organic fertilizers release their nutrients gradually and require less frequent application. After July 15, refrain from fertilizing to prevent the plant from going into full dormancy before winter. Use of lime or alkaline fertilizers should be avoided.

In the summer, rhododendrons and azaleas require a lot of water due to their shallow, fibrous root systems. Make careful to thoroughly hydrate them. You will require water all year long if they are planted beneath wide eave overhangs. Avoid going too deep when hoeing or raking around the plants. Mulches can be used to control weeds, maintain more consistent soil temperatures, and save moisture. Examples of such mulches include sawdust, bark dust, peat moss, straw, or other organic materials.

The garden is busy at the moment. These days, your vegetable garden can contain just about anything. Don’t put it off! Plant more lettuce, carrots, beets, potatoes, peas, cucumbers, squash, pumpkins, melons, dill, basil seedlings, and brassicas. Also plant more beans, tomato and pepper plants, and more lettuce.

Are lilac bushes supposed to be pruned?

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.

Is it possible to trim down an overgrown lilac bush?

The common purple lilac is a hardy, dependable shrub that can grow up to 20 feet tall. Unfortunately, the lower, shady sections of lilac shrubs typically lose their leaves as they get older. Large, overgrown specimens as a result are frequently leggy and ugly. Pruning can restore or rejuvenate old, neglected lilacs. Home gardeners have two alternative pruning techniques to pick from.

Cutting the entire plant back to within 6 to 8 inches of the ground in late winter is one method of renewing a huge, overgrown lilac (March or early April). A significant number of shoots will sprout during the growth season as a result of this aggressive pruning. Select a few sturdy, robust shoots to construct the shrub’s framework, keeping a few of them, and cut off all the others at ground level in the late winter of the next year. To promote branching, head (clip) back the retained shoots to just above a bud.

Cutting back the overgrown shrubs over a three-year period is a second method for pruning mature lilacs. In late January, start the process by digging up and removing one-third of the big, old stems. The following year, trim out half of the remaining old stems (again in late winter). Additionally, trim out some of the recent growth. Keep a few healthy stems that are evenly spaced apart and cut off the rest. In the third year’s late winter, completely remove all of the old wood. It is also necessary to thin the fresh shoots more. This pruning technique should enable you to take pleasure in blossoms every spring because lilac wood must be three years or older before it blooms.

Within a few years, with the right pruning, an old, overgrown lilac can be converted into a robust, appealing shrub. Pruning should be a frequent component of the lilacs’ management regimen after they have been revived. By cutting a few of the oldest branches every three to five years, the shrub can be kept strong and healthy.

(This article, which first published in the Sunday edition of the Lincoln Journal Star Newspaper in February 2005, has since been amended. Consult the Terms of Use for details on how to copy this content and use any images or visuals.)

How should a French lilac tree be cared for?

The fragrant spring and early summer air is filled with French or Common Lilacs. Gardeners have a nice choice in bloom color, single or double flowers, and all have the traditional heart-shaped leaves thanks to a large variety.

Uses

a time-tested favorite for focal points in landscapes. A top-notch border, foundation, or specimen plant. Excellent for planting near patios, decks, and walkways where aroma may be appreciated.

Planting Instructions

Pick a spot that will let the branches and roots develop naturally. Plants should be placed far enough from walls, decks, and building foundations to prevent the growing foliage from crowding the structure. If there are any tall trees or shrubs nearby, consider whether they could interfere with electrical lines or the roof or block windows.

Dig a hole three times as big and as deep as the root ball to prepare the planting location. Once the soil has been removed, combine it with some compost or peat moss. By enhancing the soil and aerating the current soil, new roots can easily spread.

Gently support the plant’s base while you tip it sideways and touch the pot’s exterior to loosen the plant before removing it from the container. Till the plant easily emerges from the pot, rotate the container and keep tapping to release the soil. Cutting the container down the side will also allow for removal.

In the hole, place the plant. The burlap cloth, as well as any strings or wire holding the burlap in place, must now be taken off if the root ball is covered in it. Use your fingers to gently rake apart roots that are densely packed.

Backfill the planting area with earth, pushing it tightly around the root ball. When the roots start to flare out from the main stem at the base of the plant, fill the hole until the soil line is right there.

After thoroughly watering the plant, surround the planting area with a 2 (5cm) layer of mulch, such as crushed bark. Mulch should be kept at least 4 (10 cm) away from the plant trunk to avoid keeping the bark overly damp and allowing it to rot.

Watering Instructions

Through the first growth season, young plants require weekly irrigation depending on rainfall. It should work with a gentle drip of water for an hour. It is preferable to completely wet the ground up to 8 cm (20 cm) every few days during hot spells as opposed to watering sparingly each day. Deep watering promotes roots to go deeper into the soil, strengthening the plant and increasing its resistance to drought.

Use a hand trowel or your finger to dig a tiny hole in the ground and feel the soil for wetness. It’s time to water if the top 2-4 (5-10 cm) of soil is dry.

Throughout the first two years, keep an eye on young plants to make sure they’re getting the moisture they require. They ought to be strong enough to survive on their own after that.

Fertilizing Instructions

Every two to three years, mature trees should be fertilized. Feed plants in the early spring when they begin to grow.

There are many different types of fertilizers, including granulated, slow-release, liquid feeds, organic, and synthetic. Decide which application technique is most appropriate for the circumstance, then choose a product made for trees and shrubs or opt for a nutritionally sound, all-purpose composition like 10-10-10.

For application rates and timing, always adhere to the instructions on the fertilizer package. Plant damage can occur as a result of overfertilizing plants or applying fertilizer at the wrong time during the growing season.

Pruning Instructions

To eliminate dead branches, stimulate bushier growth, encourage more flowers, or maintain a particular size or shape, pruning may be necessary.

Remove any dead branches flush with the bark, close to the trunk. Just above a leaf bud and at a small angle, cuts should be made while pruning to manage a plant’s size or shape. The fresh growth will emerge from this bud.

Numerous shrubs can be kept shaped as a hedge, edging, or formal foundation planting by routinely shearing.

Use only clean, sharp tools when pruning. Various tools are accessible depending on the task. For most bushes, hand shears, pruners, and loppers work well. For large, mature shrubs or trees, pole pruners and tree saws are preferable. It is preferable to bring in a professional tree service if a tree is too big to prune safely with a pole pruner.