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Why Are My Lilacs Not Blooming? Umm…

Lilacs are easy-maintenance shrubs that require little attention, so long as you give them their fair share of care, they will blossom.

Providing the right growing conditions is crucial and saves time and money.

Lilacs bud at least once or twice a year and make gardens beautiful. They produce a lot of fragrance when exposed to constant direct sunlight for six hours.

Lilacs, also known as the queen of shrubs, originated from Southeast Europe and formed part of the Mediterranean culture.

Lilacs have intense attractive fragrances. They come in different colors, such as pink, white, purple, and blue.

They are significant additions to gardens and make them beautiful when they flower.


Why Are My Lilac Not Blooming?

The most common reason behind your lilac not blooming is the lack of ample sunlight. Also, pruning lilac at the wrong time of the year is another likely reason it is not flowering. Temperature extremes, wrong fertilizer, overwatering, and bugs also bring about this problem. 


Inadequate Sunlight

Why are my lilacs not blooming?

Among the most common reasons that may hinder lilacs from blooming is the lack of adequate sunlight.

Lilacs need at least six hours of intense, direct sunlight daily. Lilacs planted under the shade of other plants barely blossom, although they live longer.

You can prune back trees shading your lilac shrub, for it to get ample sunlight.

Also, you have the option of moving your lilac shrub to a location where there is direct sunlight. But this isn’t always a good move because the shrub can take over a year to blossom.

Remember, shifting your lilac shrub is not a simple task.

The easiest way to let your shrub receive direct sunlight is to engage a professional arborist to trim the trees shading the shrub.

Trees trimmed by a professional grow systematically without shading other shrubs in the garden.

Another way to make lilac blossom is by propagating them. This gets done by either buying a new bush and planting in a sunnier zone.

I also cut its stems from time to time to ensure its branches are not too old or young. A good cut snaps off when bent.


Wrong Pruning and at the Wrong Time

Another primary reason lilacs cannot blossom is that they get poorly pruned or pruned at the wrong time. Lilacs comprise two types of shrubs:

  • New wood: Lilacs that bud on new wood during summer or fall, and their flower buds form on branches. If this kind of lilac gets pruned during spring, it produces more branches that accommodate more flowers.
  • Old wood: Lilacs that blossom in later years of growth

Lilacs that flourish on old wood do that during spring. Their buds form on branches that grew in the previous year.

In such a case, the shrubs should not get pruned in the spring. Otherwise, spring pruning gets rid of last year’s branches that carry the flower buds, and this can lead to no flowering.

Why is my lilac not blooming after pruning in the fall?

Pruning during the fall season isn’t a good idea. It increases the chances of cutting off branches that have already formed for next season’s growth.

The best pruning time is when the shrubs have finished developing.

Remember, pruning is not all about timing; how the pruning is done also matters. It is crucial to avoid pruning healthy branches with buds.

Your target should focus on removing undeformed or sick branches. Pruning helps lilac shrubs to blossom even.

I have normalized yearly pruning that aids in the formation of new stems. It also balances old and new shrubs, shoots, and snips off wasted buds.


Extremely Warm Winter and Dry Spring

I experience late freezes in April and May. I have noticed that in the last two months, my lilac shrubs haven’t come into bud.

The freeze can get severe and cause damage to lilac buds, causing them to fall off. Once the buds fall off, it results in little to no flowering.

Lilac needs an inconsiderable amount of cold for some days to blossom.

However, when late freezes prolong for several days, experts advise florists to cover the shrubs with a blanket or move them closer to a building if panted on pots.

This prevents the plant from freezing and destroying the buds.

Dry springs are bad for lilac because this is when the shrub is in its prime growth. So, it interferes with the blossoming of the shrub.


Wrong Fertilizer

Lilac requires little fertilizing to prevent nitrogen build-up, which is a hindrance to the budding of the plant.

Too much nitrogen causes the shrub to produce extra leaves and branches—a hindrance to its flowering.

Lilacs planted in pots need little fertilization to prevent too much nitrogen, which may cause the shrub to overgrow and outdo the pot.

An ideal fertilizer recommended for the growing of lilac should comprise ample phosphorous, which combines with good compost to produce a good mulch and contributes to proper lilac budding.


Too Much Water

Lilacs thrive in well-draining soil that doesn’t hold water. The shrubs can survive an entire summer without supplemental watering as it uses up water it got from winter.

When your lilac is not thriving, it could be due to too much water on the ground. Also, the pot may not be draining water properly, causing a wet base.

Professionals advise gardeners to water an inch of volume during hot and dry weather.



Lilac plants can get infested by bugs which will hinder them from bourgeoning. Some of the bugs likely to infest the plant include scales and borers.

I remove such pests by washing the leaves’ branches with water from a gardening pipe.

Sometimes, I mix water with neem oil as it helps eliminate the bugs in the long run. I repeat the process at least once weekly.


Frequently Asked Questions About Why Lilac Is Not Blooming


Does age affect the way lilac flourishes?

Lilac shrubs bloom best on young wood. Woody lilacs blossom less because they are old.


Can I plant lilacs in pots?

Though they look lovely outdoors, you can definitely grow lilacs in pots. However, lilacs are shrubs that spread where they get planted. So, they should get planted in big and wide pots to create enough space for them to spread.


What are the best blooming conditions for lilacs?

Lilacs thrive well in alkaline soils of prime pH levels 6-7PH. Lilacs need 6 hours of direct sun exposure for proper flowering.



Lilacs are beautiful shrubs with solid fragrances. They are common in most American yards and brighten the gardens during summer.

Under the right conditions, the shrubs blossom at least twice a year. Lilac is highly easy to maintain and needs a lot of attention to care.

Lilacs flower best when adequately pruned, watered, treated, and fertilized.

Author Bio

Daniel Iseli

Taking care of houseplants and gardening are my greatest passions. I am transforming my apartment into an urban jungle and am growing veggies in my indoor and outdoor garden year-round.