Care for Lilacs After They Flower


Lilacs are beautiful flowering shrubs that bring color and fragrance to any garden.

Once the lilacs have finished blooming, it’s important to provide them with the proper care to ensure their health and promote future growth.

In this article, we will discuss how to care for lilacs after they flower, including pruning, fertilizing, and general maintenance tips.

Pruning Lilacs

After the lilacs have finished flowering, it’s time to prune them to maintain their shape and encourage new growth.

Pruning should be done immediately after the flowers fade, typically in late spring or early summer. Here are some tips for pruning lilacs:

  1. Remove spent flowers: Start by removing the faded flowers, also known as deadheading. This will prevent the plant from wasting energy on seed production and redirect it towards new growth.
  2. Thin out old wood: Lilacs tend to produce new growth from the base of the plant. To encourage this, remove one-third of the oldest stems at ground level. This will stimulate new shoots and rejuvenate the plant.
  3. Shape the plant: If your lilac has become overgrown or misshapen, you can selectively prune branches to achieve the desired shape. Cut back any branches that are crossing or rubbing against each other.
  4. Avoid heavy pruning: Lilacs bloom on old wood, so avoid heavy pruning that removes too much of the previous year’s growth. This can result in a lack of flowers the following year.

Fertilizing Lilacs

Proper fertilization is essential for the health and vigor of lilacs. After they have finished flowering, it’s a good idea to give them a boost of nutrients to support new growth.

Here are some tips for fertilizing lilacs:

  1. Use a balanced fertilizer: Choose a slow-release, balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium (NPK). This will provide the necessary nutrients for healthy growth.
  2. Apply in early spring: Apply the fertilizer in early spring, just as new growth begins. Follow the instructions on the fertilizer package for the correct application rate.
  3. Avoid over-fertilizing: While lilacs benefit from fertilization, it’s important not to overdo it. Too much fertilizer can lead to excessive leaf growth at the expense of flowers.
  4. Mulch with organic matter: After fertilizing, apply a layer of organic mulch around the base of the lilac. This will help retain moisture, suppress weeds, and provide additional nutrients as it breaks down.

General Maintenance Tips

In addition to pruning and fertilizing, there are a few general maintenance tips to keep in mind when caring for lilacs after they flower:

  1. Watering: Lilacs prefer moist, well-drained soil. Water deeply and regularly, especially during dry spells. Avoid overwatering, as this can lead to root rot.
  2. Pest control: Keep an eye out for common lilac pests, such as aphids, powdery mildew, and lilac borers. Treat any infestations promptly with appropriate insecticides or fungicides.
  3. Disease prevention: To prevent the spread of diseases, such as bacterial blight or leaf spot, avoid overhead watering and provide adequate air circulation around the plant.
  4. Prune selectively: Throughout the growing season, remove any dead, damaged, or diseased branches. This will help maintain the overall health and appearance of the lilac.


Caring for lilacs after they flower is essential for their long-term health and vitality.

By following the proper pruning techniques, fertilizing at the right time, and providing general maintenance, you can ensure that your lilacs continue to thrive and bring beauty to your garden year after year.

Frequently Asked Questions

Why are my lilacs not flowering?

There could be several reasons why your lilacs are not flowering. One common reason is improper pruning.

Lilacs bloom on old wood, so if you prune them at the wrong time or too heavily, you may be removing the flower buds. Another reason could be a lack of sunlight.

Lilacs require at least six hours of direct sunlight per day to bloom properly.

How often should I fertilize my lilacs?

Lilacs should be fertilized once a year, in early spring, just as new growth begins. Use a slow-release, balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium.

Avoid over-fertilizing, as this can lead to excessive leaf growth at the expense of flowers.

Can I transplant my lilacs after they flower?

It’s best to transplant lilacs in early spring or late fall when they are dormant.

Transplanting them immediately after they flower can put stress on the plant and reduce its chances of survival.

If you must transplant them after flowering, make sure to provide extra care and water to help them recover.

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