Why Is My Lilac Bush Not Growing

A. There are a number of potential causes for your lilac’s failure to blossom. Lack of sufficient sunlight is the main culprit. Lilacs (Syringa) should be planted in an area with at least six hours of direct, bright sunlight per day. They can withstand a wide range of moisture levels as long as they are grown in soil with good drainage.

If your lilac is clipped at the wrong time of year, it might not blossom for another reason. Lilacs bloom in the spring on the growth from the previous year, and soon after, they begin to form the buds for the following year. Within a few weeks of the plant blooming, pruning must be done simultaneously with the removal of the wasted flowers in order to prevent the removal of the buds for the following year. A late freeze can harm flower buds on types that bloom early.

Lilacs have a tendency to mature into overgrown, leggy shrubs with minimal foliage at the bottom. When this occurs, it might be required to prune them to within 12 inches of the ground in order to completely rejuvenate them. When the shrubs are dormant in late winter, this should be done. Lilacs benefit from this repair, although their blooming cycle will be hampered for at least one season. Lilacs can receive a rejuvenation pruning over a two-year period to stop the interruption of bloom cycles. Half of the shrub’s stems should be hard pruned the first year, and the remaining stems the following year.

Lilacs do not consume a lot of food. Excessive fertilization, particularly nitrogen fertilizer, can frequently promote luxuriant vegetative growth at the expense of flower development. A lilac’s failure to bloom could potentially be due to its proximity to turf that receives frequent fertilization.

How can you assist a lilac bush in need?

Verify that the plant has adequate drainage. Lilacs shouldn’t be overwatered because doing so could cause the plant to drown. Additionally, it’s crucial to avoid submerging the bush because it won’t survive in dry soil. Check the lilac shrub leaves and the soil to see if extra water is required.

How can I speed up the growth of my lilac bush?

Lilac bushes grow fairly quickly, with some types growing more quickly than others. Any way you look at it, lilac bushes are a fast-growing variety of shrub.

By ensuring that your lilac shrub receives adequate sunlight and is placed in healthy soil, you can hasten its growth. It’s important to carefully and moderately water the lilac bush.

In the spring, fertilizer can be applied to the lilac shrub to help it grow. You should be able to observe your lilac shrub growing quickly each year if you heed our advice.

Why are the lilacs on my bush so few?

Lilac bushes with legginess have few, long, slender stems with their few flowers growing at the tips of the branches. Legginess can have a few possible causes. One is a lack of sunlight. Lack of light causes a lilac to grow upwards toward the sun and blossom on the areas of the plant that receive the most light. Age also has a role. Older bushes that are not regularly pruned and shaped tend to become spindly and focus their energy on growing upward rather than producing flowers.

Is it possible to revive a 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 are lilacs brought back to life?

Lilacs are a nostalgic flower for many individuals. On our property in Kansas, my mother planted a lot of lilac bushes. As I played, the aroma spread across the yard. In order for our children to share the same exquisite recollection of the aroma and flower, my husband and I made it a priority to plant a lilac in our garden when we first started our family.

I’ve tried, and have failed, through the years to bring this flower’s bounty into my house. Even though I had the flowers in a spotless vase filled with new water, they would begin to wilt an hour after I brought them inside. I have figured out how to make the blooms last as long as possible by trial and error:

As you trim blooms, have a pail half-full of fresh, chilled water nearby. Choose a chilly morning or evening to pick flowers. Lilacs bloom very sporadically after being harvested, so look for stems with at least 75 percent of their flowers open. Next, remove all of the leaves to prevent the plant from exerting extra energy to keep them moist. Put stems in the liquid. Allow the flowers to absorb water in the bucket for at least an hour by placing it in a cool, dark location.

Recut the stem ends next with powerful clippers, then make 1-2 inch vertical slices up the stem. Take hold of the sliced stem’s one side and twist it backward. Reintroduce the chopped stems to the water in the bucket right away. For an additional hour or two, let the stems soak up extra water in a cool, dark location. After that, the lilacs will survive three to four days and be ready for arranging.

What destroys lilac bushes?

A common chemical component of broad-spectrum herbicides is glyphosate. This poison will enter the living cells and start killing the roots when applied to the open wounds on the lilac stumps. One hour after trimming the exposed growth is the ideal window of opportunity to apply glyphosate. Check the area for the appearance of tiny, thin suckers that also need to be treated while spraying the glyphosate to the stumps that were clipped. At least 24 hours are required for the glyphosate to start acting. Rain or watering before this period will wash the chemical away and reduce its potency.

Does lilac grow slowly?

The lilac is a multi-stemmed, deciduous shrub with an erratic, rounded shape. When young, it grows quickly, but as it ages, its growth slows to roughly one foot every year. The stems’ sturdy wood has a dark gray to gray-brown color. The leaves are light green underneath and dark green to blue-green above. The clusters of four petal blooms, which come in lilac, light purple, or lavender hues, bloom in April or May. They have a strong fragrance. Although the lilac thrives best in sunny locations, it cannot stand hot, muggy weather. It requires moist, well-drained soil that is neutral or just a little bit alkaline in pH. Peat or leaf mold can be added to the soil as a supplement. As soon as they start to fade, old flowers should be removed. Lilacs should be pruned as soon as they finish blooming. Pruning the shrub is preferred since it will highlight the medium-aged wood, which will still contribute to the plant’s good size and produce nice blooms. Remove a third of the earliest stems at ground level each year to accomplish this. Any remedial trimming, like removing competing branches or sucker growth, can be done concurrently. Pruning older lilacs as small, multiple-branched trees will highlight a few massive, old trunks while removing sucker growth and making them a focal point of the landscape. The shrub can also be pruned into a tree with a single stem. Lilacs that are overgrown can be pruned to a few inches above the surface. They will bloom once more in three to four years, Depending on the mature height, space your plants 3–4 feet apart if you want a hedge.

How much time does it take a lilac shrub to grow?

Lilacs produce flower buds for the following year after blossoming in the current year, just like other spring blooming plants do. Lilacs should be deadheaded as soon as they finish blooming to promote healthy bud growth for spring flowering.

  • Deadhead: For larger plants, use a hedge trimmer or a hand pruner to remove dead flower heads down to a pair of leaves. Shear gently, just removing the dried flower heads.
  • Renewal pruning: Renewal pruning promotes the growth and flowering of new stems while distributing more light throughout an older plant. Lilacs that have just been planted often don’t require trimming for 2 to 3 years, and it might take up to 2 years for a lilac to blossom. Lilac stems have a tendency to shadow out new growth at the base of the plant as they enlarge and become more like trees over time.
  • Remove a third of the base of the thickest stems with a lopper or handsaw.
  • Repeat this each year until all huge stems have been cut off.
  • For smaller, thickly branching lilacs like Korean or Meyer lilacs (Syringa meyeri) that have overgrown, rejuvenation pruning is a strategy.
  • Use a saw or hedge trimmer to chop the entire plant to the ground in the late winter.
  • In the spring, fresh growth will emerge from the root zone.
  • For one or two years, the plant might not bloom at all or only sporadically.
  • Make sure to choose cultivars that are disease-resistant because powdery mildew is simply aesthetic.

Are lilacs challenging to grow?

Did you know that the National Gardening Bureau has designated 2022 as the “Year of the Lilac”? They have a sweet, eerie aroma and are among the easiest shrubs for your landscaping to maintain that bloom in the spring. Find out how to plant, nurture, and prune your lilacs.

About Lilacs

Syringa vulgaris, or common lilac, is prized for its tenacity, dependability, and scent. Lilacs are so hardy that they can live for more than 100 years and frequently outlive the houses they were planted near.

This tiny, multi-stemmed deciduous shrub (or tree) has approximately ten canes and blooms at eye level. The height of a common lilac can range from 8 to 12 feet, depending on the cultivar. The aromatic flowers attract butterflies and make good cuttings.

There are lilac types that come in white, cream, and even pink and yellow, though the blooms are typically lilac/purple in hue (ranging from very pale to extremely dark). Flowers can be solitary or double in number.

Lilacs bloom in northern states from mid- to late spring for around two weeks. However, there are lilac varieties for early, mid, and late seasons that, when cultivated together, guarantee a consistent bloom for at least six weeks.

Lilacs do best in soil that is fertile, humus-rich, well-drained, and neutral to alkaline (at a pH near 7.0). Add compost to your soil to improve it if it is in bad condition. (Learn more about adding amendments to the soil and getting it ready for planting.) Lilacs don’t enjoy having their feet wet and won’t blossom if they are kept too moist, so make sure the planting area drains well.

Lilacs should be planted in full sun, which is defined as having at least six hours of sunlight each day, for the finest blooms.

How to Plant Lilacs

  • If you’re fortunate, a friend may offer you a sucker, or offshoot, of the plant’s root system. The sucker will first appear pitiful, but all you need to do is dig a hole, fill it with soil, and then insert the sucker. water next, and then wait. You’ll be rewarded with enormous, fragrant blossoms in 4 or 5 years.
  • Lilacs purchased from nurseries can also be planted easily. If the plant was cultivated in a container, spread its roots out as you plant it; if it was balled or burlapped, gently remove the covering and any rope before doing so. Set the plant 2 to 3 inches deeper than it was while it was growing in the nursery and cover the roots with topsoil. in water Then add more topsoil to the hole to finish it.
  • Depending on the kind, place multiple lilac bushes 5 to 15 feet apart.
  • Apply a layer of compost under the plant each spring, followed by a layer of mulch to keep moisture in and weeds under control.
  • If the weekly rainfall is less than 1 inch, water during the summer.
  • If lilacs receive too much fertilizer, they won’t bloom. In the late winter, they can manage a few 10-10-10, but no more.
  • Spread some lime and thoroughly composted manure around the base of your lilac bush once it has finished blooming. Remove suckers while you form the shrub by trimming it.

Pruning Lilacs

  • Since lilacs blossom on old wood, it’s important to prune in the spring immediately following their bloom. You risk removing the wood if you prune later in the summer. A word of advice: It’s time to prune if your lilac flower clusters are getting smaller!
  • After bloom each year, cut away any dead wood. Remove the oldest canes by pruning (down to the ground). Take out the tiny suckers. Reduce weak branches until a robust shoot remains. Reduce tall canes to eye level.
  • Remove one-third of the oldest canes (down to the ground) in year one, half of the remaining old wood in year two, and the remainder in year three if your lilac is very old and in poor condition. Cutting the entire plant back to a height of approximately 6 or 8 inches is another option for elderly lilacs. Although it sounds dramatic, lilacs are remarkably resilient. This option’s drawback is that it takes some time for the hair to grow back. The lilac will grow back bursting with blooms, so there will be less work and more reward.
  • It is important to understand that extreme trimming causes bloom loss for one to three years. For these reasons, a smart pruning program gives the bushes yearly attention in an effort to avoid making dramatic and severe cuts.

The Syringa vulgaris kind of lilacs is the most widely grown and fragrant:

  • Try the double magneta variety “Charles Joly” for an early bloom.
  • Lilacs in the middle of the season include “Monge,” a deep reddish purple, and “Firmament,” a delicate blue.
  • Miss Canada, a reddish pink, and Donald Wyman, a solitary purple, are two late-season beauties.

Syringa x hyacinthiflora, an early-flowering lilac cultivar, opens 7 to 19 days before those of the common lilac. Hummingbirds and butterflies are attracted to its fragrant blossoms.

The cutleaf lilac, a fragrant pale lavender, is one of the common lilacs that may flourish as far south as Zone 9. Common lilacs appreciate cold weather. The beautiful shrub Syringa patula ‘Miss Kim’ has light lilac-blue flowers that eventually become white.

There are tiny kinds for gardeners who simply don’t have the space for the conventional larger lilacs, particularly those in urban settings. Even in a container on your balcony or patio, they will grow.

  • ‘Baby Kim’ has a lovely rounded shape, only grows 2 to 3 feet high (and 3 feet wide), and has purple flowers that draw butterflies. Hardiness from Zones 3 to 8 extended.
  • Compact lilac ‘Little Lady’ (Syringa x) has dark pink buds that open to lilac-pink flowers and grows to be 4 to 5 feet tall and wide at maturity. Zones 2 to 7 are tough.
  • Syringa vulgaris cultivars “New Age Lavender” and “New Age White” were developed for mildew resistance and are quite compact, growing from 4 to 5 feet tall and wide. Hummingbirds and butterflies are drawn to their fragrant blossoms. Zone 4 hardy.