Lilacs often bloom quite consistently, although occasionally they don’t. To ensure that yours grows, follow these suggestions:
- Usually, the issue is a lack of sunlight. Each day, the sun should be exposed for at least six hours.
- Nitrogen in excess might be problematic. Lilacs are frequently cultivated in lawns, and nitrogen-rich fertilizers are utilized to make lawns greener. This results in lovely green foliage on the lilac but minimal blossom. Avoid using nitrogen-rich fertilizers.
- Make sure to prune when the season is perfect. Remove any dead or damaged timber in the early spring. However, avoid performing any significant pruning because you can just remove the dormant flower buds. It’s acceptable to perform more significant trimming after the flowers have faded, such as reshaping or rejuvenating an elderly bush. The old flowers can be taken out as well. Just be sure you finish it before the middle of the summer. A few of the flowers from the upcoming season may be lost if you wait too late.
Visit the Lilac Planting and Care page for a comprehensive guide to lilac planting and care.
How can I increase the blooming of my lilacs?
Lilacs with good form require annual pruning to maintain the rounded shape that most gardeners like. For the purpose of regulating the shrub’s total height, pruning is also crucial. These robust growers can grow up to and over 20 feet tall, depending on the variety. A tall lilac’s flowers will also blossom close to the top of the plant, out of reach and possibly beyond where they can be easily seen and appreciated because the majority of the buds develop on the tips of the branches.
- Pay close attention. This spring, as your plants blossom, pay particular attention to the shrub’s shape. Note where the plant has the most of its flowers as well. Lilacs bloom toward the tips of their branches; the sunniest spots will have the largest and most vibrant flowers.
- Selectively prune. Selective pruning should be done after the blooms have faded and died to manage height and restore shape. Lilacs typically only need to be deadheaded and a few choice branches removed to enhance the form and look of the plant. It’s vital to only prune the limbs and branches required to maintain a properly shaped and proportionate shrub because they flower on the older stems.
- Cut those suckers off. Each year, healthy lilacs send up new suckers from the ground. Cut back some of the suckers and get rid of any twisted or lanky branches.
- Cut back by a third. The inside of the plant may get crowded with a tangle of older limbs over time and as it ages. Lilacs will consistently bloom for years with no maintenance, but some elderly plants may start to produce less. Cut back the chosen shoots and branches at ground level to eliminate around one-third of the plant each year in order to revitalize an older plant and promote more flowers.
Does pruning encourage or delay a lilac’s growth?
Although harsh pruning promotes new growth, because lilacs only bloom on old wood, it may take the plant several years to recover from a severe pruning before it can bloom effectively once more.
Which fertilizer is ideal for lilacs?
Lilac plants don’t require a lot of food or fertilizer. A 10-10-10 fertilizer mixture applied yearly in the early spring is what we advise. (The amounts of nitrogen, phosphorus, and potassium, or NPK as they are popularly known, are represented by the digits 10-10-10 in the formula.) Early spring fertilization of lilacs with a high phosphorus solution encourages blossoming.
Coffee grounds and grass clippings are also excellent sources of nitrogen. Use in moderation since an excess of nitrogen in the soil can lead to subpar blooms. The ideal soil conditions for lilacs are slightly alkaline (6.5–7.0 pH), wet, and well-drained. The soil may become more alkaline by adding bone meal to it. Use Miracle-Gro Shake ‘n Feed Flowering Trees & Shrubs Plant Food in the spring if you decide to feed your plant. Last but not least, lilac plants dislike acidic soil. Epsom salts can be used to encourage blossoming while the plant is dormant.
Why aren’t my lilac bushes in bloom?
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.
Sun and shade
Bloomerang lilac trees need at least six hours of direct sunlight each day to grow and flourish. Although they can withstand little shade, they won’t grow as many blossoms.
Soil
Trees prefer alkaline, well-drained soil that is wet. Their roots may being damaged by wet soil. The right amount of moisture can be retained and the Bloomerang can be shielded from temperature changes by a thin layer of mulch.
Watering
The blooming season is when bloomerang lilac trees will require the most water. From spring through the end of bloom season, right before the first frost, water once every ten to two weeks. Two inches of water are required for your tree to receive moist soil that is down to 12 inches.
Water during prolonged dry spells the remainder of the year if the top three inches of the soil begin to totally dry up and if the leaves begin to wilt.
Fertilizing
Beginning the second year after planting, you can fertilize your Bloomerang lilac tree in the first few weeks of spring. Apply a lilac-specific fertilizer to your plants. These often contain more phosphate and potassium and less nitrogen. A good NPK value is 5-10-10.
Pruning
You don’t need to prune your Bloomerang lilac tree. Your tree will blossom once more regardless of whether it encourages new growth. If you choose to prune your tree, do it as soon as it blooms. The flower buds will be severed if it is done in the fall, winter, or before the first bloom. Trimming will cause the rebloom to happen a few weeks later.
How are lilac Fullers made?
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.
Does Miracle Grow benefit lilac plants?
When the lilacs begin to blossom, it is a solid indicator that spring has arrived for good. While many people only have a limited knowledge of common lilac (also known as French lilac) shrubs that can reach a height of 15 feet or more, there are now a lot more options available than there were fifty years ago. Some varieties that rebloom enhance the garden’s appeal the entire growing season.
How to Choose Lilacs
The common lilac is what you will most likely find when you go plant shopping. This traditional plant comes in a variety of cultivars and variations, each of which yields fragrant spring flowers in pink, purple, white, or even combinations of those hues. Common lilacs are typically the most fragrant variety of lilac and can grow to be rangy and large.
Rebloomers have arrived in the garden center thanks to recent introductions of hybrids between the common lilac and other shrub-type lilacs. Some of these more recent types are a little less fragrant, but they also tend to be smaller, bloom more frequently throughout the growing season, and have fewer powdery mildew issues.
The tree lilac is another common variety of lilac. It can grow to a height of around 20 feet and blooms with cream-colored flowers in the middle of the summer. Though it doesn’t require much trimming, keep in mind that the tree lilac is a tree, not a shrub.
Where to Plant Lilacs
Lilacs should be planted in full light (at least 6 to 8 hours per day), as too much shadow will prevent them from blooming. Lilacs also prefer moist, well-drained soil that is slightly alkaline.
When to Plant Lilacs
Before the ground freezes in the late fall is the ideal time to plant lilacs. After the earth thaws in the early spring, that is the next ideal period to plant. Lilacs will likely need to be planted as soon as you can locate them at the garden center, which is great; if you choose to do so during a warmer season, they might require additional watering.
How to Prepare the Soil for Planting Lilacs
A soil test should be performed prior to planting since lilacs thrive in slightly alkaline (6.5 to 7.0 pH), moist, well-drained soil that is high in organic matter. Lime must be added to raise the pH if it is below 5.5. It’s time to get the soil ready when you’ve obtained the ideal pH. Improve individual planting holes by mixing Miracle-Gro Garden Soil for Trees & Shrubs in a 50:50 ratio with the natural soil to give lilacs a nutrient-rich start. Iron and phosphorus are also present in this garden soil to promote root development and ward off leaf fading.
How are lilacs kept in good health?
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.