How To Fertilize A Lilac Tree

During their second year of growth, feed your lilacs.

For larger and better blossoms, scatter some fireplace ash around the drip line of your bush.

-When handling chemical fertilizers, always put on protective gloves and a face mask.

-Strictly adhere to the instructions and storage recommendations on the fertilizer label.

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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.

What about coffee grounds and lilacs?

Use only a small amount of coffee grounds and grass clippings in your compost; they are good sources of nitrogen. The soil receives potassium from banana peels.

How frequently should a lilac tree be fertilized?

Lilacs don’t need fertilizer the first year after planting. When the shrubs are a year old, in the spring after planting, start applying annual fertilizer. Wood chips are a good example of an organic mulch that controls weed growth, retains moisture, and reduces disease risks.

How can I improve the bloom of my lilacs?

Although there are several potential solutions to this problem, pruning might hold the key. Lilacs blossom on the growth from the previous year, so it’s crucial to cut them as soon as the spring blooming is through. Pruning a lilac in the summer, fall, or winter may result in the removal of buds that would have bloomed the following spring.

After the spring bloom, try to only lightly prune the plant. If you want to avoid delaying the next bloom by drastically pruning your lilac shrub, simply remove the oldest and heaviest branches and trim the inner branches to make room for sunshine to enter the bush.

Take into account the age of your lilac bush, which by this point may have evolved into a tree. On younger wood, lilacs bloom at their best. If the majority of your lilac’s structure is old, decayed wood, blooms may be scarce. An elder lilac can require rejuvenation pruning, followed by a two- to three-year wait before it can bloom fully again.

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.

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.

Do lilacs need to be fertilized?

Lilac bushes respond well to fertilizer made from bone meal. This is as a result of increased soil alkalinity. It is a simple natural plant food that the lilac may consume.

Lilac fertilization isn’t necessarily required until the first and second years after planting. To sweeten the soil and prevent too much acidity, they could be fertilized with superphosphate and limestone when they are planted.

You can exclude standard fertilizer mixtures if the soil has the right balance and has a lot of organic matter. The only bushes that will truly benefit from annual feeding are those planted in poor soil. When you do feed the plants, use a 5-10-10 ratio. Around the plant’s root zone, distribute 1 cup (237 ml) of granular food evenly, and then water the soil.

Which plant fertilizer is best for lilacs?

Lilacs require a high phosphorus feed when the soil is deficient in phosphorus, which can only be determined through a soil test.

When nutrients are transformed into food that your flowering trees can use, phosphorus plays a crucial role. It is the primary component of an NPK-listed fertilizer and is represented by the second number on the package.

It aids in the promotion of healthy root development in addition to being necessary for the production of blooms and bruit. It can also be found in bone meal, where it combines with calcium to form calcium phosphate.


You can obtain bonemeal in the form of a powder by grinding animal bones. It is steamed by manufacturers to create plant nutrients. So, to ensure that your plant stays healthy, add some of this lilac fertilizer to your soil if it needs to be more alkaline.

Epsom Salt

You can hasten the blooming of your indoor plant or the lilac in your garden by mixing Epsom salt and sugar. Your lilac bush will grow bushier and produce more flowers and chlorophyll as a result of using epsom salts. However, avoid overfertilizing your plant because it won’t flower.

Add Other Organic Matter

When it comes to organic matter, you may discover them in a number of solutions that are available to create a safer atmosphere.

Compost, manure, bone meal, and fish emulsion all include plant fertilizer. Additionally, as a good nitrogen source, you can use coffee grounds or grass clippings, but only in small amounts.


Use Miracle-Gro Water Soluble All Purpose Plant Food when fertilizing lilacs. The fertilizer is excellent and won’t burn the foliage. For optimal results, feed your lilac once every 14 days while it is actively developing.

  • The Miracle-Gro Garden Feeder can feed all of your outdoor plants in two ways and can cover up to 500 square feet in 12 minutes.
  • Adding one tablespoon to each gallon of water will allow you to use it with a watering can as well.
  • You simply need to combine half a teaspoon per gallon of water every two weeks if your lilac is grown as an indoor plant.

Leading Lilac Fertilizers

The following feeds are also options for your lilac plant if you’d prefer something different:

The BioAdvanced 701700B is a great alternative because it offers a special combination of nutrients to fight pests and promote lilac growth. It is a multipurpose plant fertilizer that kills pests and stays in the soil to maintain the health of your lilac plant. Your plant absorbs water through the roots even when it rains.

Your lilac plant will benefit from Scotts 200910 Evergreen Flowering Tree Food because it thrives in acidic soil. Utilizing it encourages blossoming and supports the development of strong roots. It also contains the ideal ratio of organic nutrients.

Jobe’s 06105 Fertilizer Spikes are made up of soluble potash, phosphate, and ammoniacal nitrogen. As a result, applying the feed only needs to be done once every eight weeks.