When To Fertilize Lilacs

Lilacs are renowned for being a simple flower to grow. For gardeners who don’t have a lot of free time, this low-maintenance plant is ideal.

Plants that grow lilacs don’t require much fertilizer. After the second year of planting, we advise fertilizing your plant. Early in the spring, treat your plant with a 10-10-10 all-purpose fertilizer to encourage blooming.

When exactly do I need to fertilize my lilac bush?

Pruning the bushes after bloom will revitalize aging, carelessly maintained plants that have developed into tangled masses of suckers.

Although lilac bushes can receive early-spring fertilization, cutting out one-third of the old canes over the course of three seasons is a superior strategy to revitalize these drained, elderly plants. This will allow the blooms to develop while also allowing for the emergence of new growth. To make way for the flower buds that will grow in the upcoming season, remove the spent blossoms.

How can I make my lilac bush produce more flowers?

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.

Do lilacs respond well to Miracle Gro?

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.

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.

Which fertilizer is ideal for lilac plants?

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.

Does coffee help lilac bushes grow?

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.

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.


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.


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.


Beginning the second year after planting, you can fertilize your Bloomerang lilac tree in the first few weeks of spring. Apply a fertilizer made especially for lilacs; they usually contain more phosphate and potassium and less nitrogen. A good NPK value is 5-10-10.


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.

Should lilacs be deadheaded?

Dwarf lilacs that resemble ordinary lilacs include the “Palibin” Meyer lilac (Syringa meyeri “Palibin”) and the “Miss Kim” Manchurian lilac (Syringa pubescens ssp. patula “Miss Kim”). However, they hardly ever need pruning for maintenance, though you can do it sometimes for shape. They can also profit from deadheading, just like other lilac kinds.

The act of manually removing withered blossoms from a plant is known as deadheading. This encourages some plants to continue blooming. But only during the first several years of growth does deadheading seem to make lilacs bloom more effectively.

Within two to five years, young lilac plants should start blooming. Deadheading the spent blooms when the plants are young encourages the plant to focus its energy on developing new buds. It won’t require this stimulation once the plant has grown older, and you’ll probably have so many flowers that the task would take too long.

Your lilac will blossom beautifully some years, and less so other years, just like with any plant. Blooms frequently rely on the climate. You will be rewarded with an abundance of blossoms the next year if you have a beautiful summer during which strong new growth emerges. Less flowers will bloom in a summer with harsh weather. Therefore, if your lilac’s color changes from one year to the next, don’t get alarmed. The blossoms will come as long as the plant is strong and you continue with maintenance pruning.

How much water do lilacs require?

A traditional flower garden, outdoor space, or decorative pot should all contain lilac plants as they are a staple flowering shrub. Zones 3 through 8 are suitable for growing these fragrant shrubs, and they require very little maintenance. Lilacs need at least 6 hours per day of direct sunlight to produce their best flowers. Lilacs benefit from regular watering after initial planting, throughout active growth seasons (spring), and during prolonged dry spells. Lilacs are fairly drought tolerant once they are established.

It is advised to water your lilac plant once every 10 to 14 days from spring till blooming is finished. The ideal irrigation for lilacs is deep, infrequent watering. Make sure the planting space or container has good drainage. These plants don’t appreciate having their feet wet and won’t bloom if they are overwatered. By saturating air pockets with water and reducing soil oxygen levels, excessive water can strangle the lilac tree’s roots. The first indication that the lilac is overwatered is the plant wiggling.

When do lilac bushes need to be pruned?

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.

What stops a lilac bush from blooming?

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.