Lilac Not Blooming? Fix it

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Have you wondered why your Lilac bush is not blooming or flowering? There can be several reasons and I list them here and how you can fix them. 

I get asked all the time why someone’s lilacs are not flowering so here you go. A full list of reasons for non-blooming Lilacs.

 

dark purple lilac bloom flower
Pink Lilac

 

There are several possibilities and I tried to list most of them.

Your lilac may not be blooming because a late freeze damaged the blooms.

We get late freezes often here in April and May. If the freeze is severe it damages the lilac buds enough that they fall off.

We either get no blooms that year or very few.  The plant itself is fine but we must wait another year to enjoy a bounteous display of fragrant blooms.

If you know you get late freezes you can plant your lilacs closer to a building.

If you have established plants and you find out you will get a late freeze you can cover the lilac with a blanket, garden cover cloth or sheets.

Many times a late freeze will be only a night or two.

Improper Pruning of Lilac Bush

The buds were pruned off last year.

The new buds form shortly after the flowers die back so any hard pruning should be done as soon as the plant is done blooming.

Here that is in June. (it may be different in your area)

If you prune after that then you need to be more judicious.  For more on pruning Lilacs see this post, I go through why to prune as that determines how you prune.

White lilacs, Flower patch farmhouse

Insufficient amount of light to bloom

Another reason your lilac is not blooming could be that the plant is not getting enough sunshine.

Lilacs lacking in blooms can be planted in an area that is either shaded by other trees or something else. It will live but not bloom.

A lilac bush needs at least 6 hours of sun or more in order to bloom its very best. You can move it or prune back the trees shading it.

Be aware that transplanting lilacs may delay bloom for another entire year so be patient. 

Also, you might need to thin the bush to make sure sunlight is getting through the foliage.

All the best tips & tricks

Grow Beautiful Blooming Lilacs!

Grow these sweet-smelling shrubs in your garden and enjoy the abundance of bloom that is a true harbinger of Spring!

Easy to grow and maintain!

Lilac Age

It has not been pruned or maintained for over 5 years.

Lilac bushes bloom best on younger wood, 5 or 6 years old and, if your lilac is mostly wood older than that then the number of blooms will be reduced.

You will need to do a rejuvenation pruning on the bush. See how to prune your Lilacs.

heirloom lavender lilac bush in full bloom, Flower Patch Farmhouse

Fertilizing Lilacs 

Is your lilac near your lawn that gets high nitrogen feed to green it up?

Lilac bushes that won’t bloom could be the result of too much nitrogen.

Lilacs don’t typically require feeding, improper fertilizing can cause a lilac to take up too much nitrogen, which encourages the plant to green up but prevents the lilac bush from flowering.  

If you have a lilac near a lawn and don’t want to move it, try adding phosphorus to the soil around the lilac.

Bone meal is a great way to add phosphorous but be aware it also can attract critters. 

Note: It takes at least a year for the bone meal to break down so don’t expect instant results.

Rock phosphate is another and Bat Guano too.

But really if you add a good compost once a year as a mulch around the base of your Lilac you should do fine.

Your Lilac gets too much water

Lilacs don’t like wet feet.

Many of the best-performing lilacs around me are in gardens of homes that are not lived in and they get no supplemental watering all summer.

We don’t get summer rains, so they survive on what they get in the winter months. If your lilac is failing to bloom check to see that it does not get too much water.

Lilac does not need more than an inch a week during hot, dry weather. 

French lavender bloom in white pines, Flower Patch Farmhouse

Is your container Lilac not blooming?

A lilac planted in too small of a container will fail to bloom.

Pot it up into a larger container using good potting soil (not one with added fertilizer) and give the roots some room and you should be rewarded with blooms the following Spring.

Lilac Pests

Around here I have not noted pests in the lilacs.

But in other areas Lilacs not blooming can be because of borers and or scale. If it is pests, normally the entire plant will look to be suffering.

Your non-flowering lilac may need a good rejuvenating prune to eliminate the borers and scale. Scale can be also treated with Neem oil while the plant is dormant.

Be judicious with Neem oil, it is an organic solution but still is a broad spectrum. Meaning it kills good bugs too.

An extremely warm winter can prevent Lilacs from blooming.

Cold winter weather helps to promote blooms. Think back, was your winter warmer than usual?

To bloom well Lilacs need a certain number of days of cold. There are some varieties now available that do well in warmer climes. I list them in this post.

A lilac not blooming may need a whipping

I know people think this is odd, but it does seem to work.

Take a broomstick, rubber hose, or something similar (some feel a rolled-up newspaper is enough) and whip the trunk of the lilac in early spring. (since Lilacs set their buds the previous Summer you won’t see results until the next blooming season)

I was taught this by a nurseryman I found one-day beating plants with a short piece of rubber hose at his nursery. This works not only on lilacs but on fruit trees as well. 

The reasoning behind this is it shocks the plant into production.

I hasten to add there is no science to support this. (garden myth?)

However, when plants have mechanical stress, this can cause them to produce ethylene gas which may affect the blooms.

So as a last resort to get your failing-to-bloom lilac to perform, give it a good beating and see what happens.

If done right it does no harm to the plant or the environment, so why not. 

And that my friends are some of the most common reasons a Lilac may not be blooming or won’t bloom. 

My favorite garden read right now is this.

Happy Gardening!

More Lilac Info for You
How to Grow Lilacs
Propagate Lilacs from Cuttings
Get More Lilacs from Suckers


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26 Comments

  1. Just prune and enjoy, it sounds like it is healthy enough to last for decades more.

  2. My bush is probably over 20 years old. We have cut it all the way back about 5 years ago it is probably 15 feet tall. It seems that it did have more blooms this year than it has had in years. Is it to old now? Should I dig it up and start over?

  3. I wish I could give you a direct answer but there are so many variables. It could be the variety of Lilac or the micro climate of your garden, too much water, not enough? You would be better served by asking a local nursery or a gardener in your neighborhood. They would be better equipped to tell you what may be the problem in your area. Sorry I could not be more help.

  4. WOULD VERY MUCH APRICIAN says:

    8 years ago, I ordered 2 lilac twigs from a catalog. Lilac is my favorite flower. I’m German and live in Texas near Abilene. The ground on my land is very poor, but I planted those lilac sticks with good dirt. One is outside my bedroom window, the other one I planted in the front of my house. After 8 years, the one by my bedroom window has spread out into a bush. It’s about 3 feet tall. The one in the front barely grew up to be 2 feet tall and looked pitiful. Has a few green leaves on it. I remember the scent of the lilac drifting into our windows. The one in the back of my house keeps spreading out, but not the one in the front. Both plants get plenty of sun all day long. I have used fertilizer, pruned it. I so very much would like my lilacs to bloom before my time comes. I’m not a gardener with a green thumb. Everything else I planted didn’t survive. So, what is the problem with my lilac? Why won’t the produce flowers? If you could solve that riddle, I would very much appreciate it. I would be extremely happy with just one flower blooming. Thank you and have a pleasant day. Gigi.

  5. Do you have a smart phone? Use a plant app to identify it. I have found them most useful. I use the free version of Plant Snap.

  6. I have what i believe is a lilac bush, it has buds but never blooms. I have photos.The buds are dark purple almost black. I have questioned if it is a lilac because of the fact i don’t see flowers and the leaves underneath are sticky.

  7. Sorry that has been the case. Time to try another and give this one to a friend who may want to try it in their garden. Or try relocating it in your garden if you wish to try again. I don’t blame you if you want to try something else though. If a plant doesn’t do well for me, I give it the boot!

  8. Michael Duffy says:

    According to this I have been doing everything right and still won’t bloom. Plenty of new growth every year 10 ft tall 4 ft across been planted for 7 years. Never bloomed.

  9. To see if it is still alive just scrape a branch, if you see green it is still alive, if not then you know that branch is dead. Or you can bend the branch to see if it breaks, if it is alive it should just bend without snapping off.

  10. Roberta Wright says:

    I bought a Miss Kim lilac bush 3 years ago, it had blooms all over. The following year it had no blooms but plenty of leaves, and the year after that it had no leaves at all……….it looks dead but I hesitate to pull it out of the ground just yet. It gets around 5-6 hours of sun per day in the growing months and it gets enough water. I don’t have a clue what I am doing wrong!! How can I tell if it is dead and pull it? Thanks

  11. Try pruning out 1/3 of the stems, to the ground. Do not prune any others at all and see if that helps. Or move it, sometimes location makes a huge difference. Did it bloom well for the folks that gave you the suckers?

  12. Beth Longar says:

    Where are you? Wondering if all this would help in Maine? We have one lone lilac in our backyard that has never bloomed in the four years we’ve had the house. I’m so sad!! I’m not a gardener (the only thing that has survived me is my children🤣) but I sooo want some lilacs!!
    Also, any thoughts on getting lupine started and helping our peonies?
    Thanks in advance!!

  13. I was given several lilac suckers at least 7-8 years ago. I get 1-2 blooms at most, though it has grown into a huge bush. It is on the southwest side of the house, beside the garage, and gets plenty of sun. I don’t fertilize that bed, which is well drained and mulched with spruce bark. I prune every year when my neighbors’ lilacs have bloomed. I even tried bonemeal. This year it has put out several suckers. I’m about to chop it down and buy a new one. So disappointed!

  14. No not at all, just enjoy. I just planted some lilacs I had in containers in the ground this June as well. The lilac will appreciate being able to stretch its roots. Fall or Spring has its advantages but it isn’t the only time to plant. Just keep is from drying out and it should be fine.

  15. Hello
    I bought a 3 foot grown lilac from garden centre in June, feet. I planted it at the end of June this year. It will grow up to 4 meters.

    Did I make a mistake to plant it in the ground in late June? Should I have waitid until fall or spring?

  16. Some lilacs can take a long time to bloom typically 3 years or more. So I would say not to give up on it yet. It doesn’t sound like you are doing anything wrong so just hang in there and it should bloom for you.

  17. I bought a lilac bush about 2 1/2 years ago at a big box store. And planted it at the front(south facing) side of my house. It gets sun ALL day.
    I grew up in Chicago and lived in a house that had no grass in the back yard, but had tons of lilac bushes on the side. I use to pick those lilacs several times a season for my mother, back in the 60’s.
    Now, I’m retired, and memories flooded back of those days and how great they smelled.
    I’ m not adept at gardening. but I wanted to plant a lilac bush for the smell.
    So….2 1/2 years after I planted the lilac, it’s over 4 feet tall, and no flowers. No smell at all.
    I watered it once or twice during a drier season. Never pruned it. Tried to keep leaves and other plants & weeds from growing around it.
    What am I doing wrong? Don’t want to give up on it yet.
    Any suggestions?
    Thank you

  18. It can take a few years to bloom, just be patient and let it get established. Shrubs are a long game in the garden. I am sure it will do fine and you will be rewarded with bloom in a future Spring.

  19. Barbara Turner says:

    I planted a new, small lilac bush late last summer. It’s in full sun much of the day and survived a freezing winter. It’s growing and looks healthy but I’m not sure what buds look like. Is it too new to begin blooming?? How do I help it grow and bloom? Thank you!
    Barbara from Springfield Illinois

  20. I know it sounds strange but what can it hurt if you are not damaging anything. Worth a shot.

  21. Im gonna whip it so good

  22. sounds like a late frost or freeze zapped the buds. Clip them off and wait for next year.

  23. Deborah Hewitt says:

    My lilacs got buds but they turned dark and never opened .what should I fon

  24. Ida Sheehan says:

    Awesome!! I think my husband has been watering too much, well I hope that’s it. But you are very helpful!

  25. Margaret May says:

    You are the best yet. I planted a Lilac bush in my yard it gets sun and shade. It was a little piece taken from a neighbor’s tree. It took a good four years to get it to grow large and finally last year it bloomed flowers. But I think I cut to much whenal I prumed the bush. Now this summer I have no flowers just the leaves which look very healthy. Also it’s more shade in afternoon than sun. It dose get at least 6 hours of full sun.

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