Lilac bush gets almost no blooms!

I have a white lilac bush that hardly gets any blooms on it. I know for sure that it's at least 20 years old, since it was here when we bought our house, but the neighbors think it is at least 30 years old or older. Based on when some of the other trees and bushes were planted, it's probably closer to 40 years old. I can't remember if it bloomed well or not back when we bought the house. We moved away after 3 years, and when we moved back in 9 years ago, it still looked very healthy, but it has never had many blooms. In fact, there are so few blooms this year that I barely even notice them.

I pruned the bush a little bit about 4 years ago, and removed any dead wood that I could find, especially in the middle. I also cut out what appeared to be the oldest wood from the center, but didn't do much trimming at all on the healthy branches. I just cut a few that were sticking out a little farther than I liked, but that didn't amount to much. Most of the branches weren't touched, so I know I didn't cut off any of the developing buds for the next year. Also, that was 4 years ago, and I haven't pruned it at all since then, so that shouldn't have been an issue this year.

Someone suggested that I cut it to the ground and let it start over again with new growth, but I'm not sure if that would even work! Do lilac's eventually get too old to bloom? Any suggestions would be most appreciated!

Natalie

Lilacs generally produce more flowers, the older they get and the less pruning they get. Not sure why yours isn't, maybe a soil nutrient issue? Perhaps too much salt in the soil, if you get any spray blowing up from the lake?

Resin

Is it getting enough sun? If it's shaded too much by the house or being under large trees or something that could prevent it from blooming well.

Resin, I don't live anywhere near the Great Salt Lake, so it's not getting salt sprayed on it, and there is no salt in the soil. I always keep finely ground mulch spread under the bush, which works into the soil over time, so I think the soil is good. I've never added any fertilizer to the bush, so maybe that is something that I should be doing? Can you suggest something that may help?

Regarding shade, it does get some shade afternoon, but I've never thought it was too much shade. I have a purple Lilac on the North side of my house that was in heavy shade, thanks to the neighbors huge cherry tree, and it has always bloomed like crazy. The neighbor had her cherry tree cut down in early Spring, and I thought the bush may be stressed from all the sun, but it did okay. It didn't bloom quite as well as usual, but I expect it to be back to normal next year. Is there a guideline to go by on "too much shade"?

Thanks, Natalie

Maybe some photos would help.

Closer view

Some of the wood on the inside. There are lots of leaves on the ends.

Leaf

Leaf arrangement, with what appears to be buds?

These buds are at the end of many of the branches, and possibly all of them. I didn't look at all of them, so I can't say for sure. I assume that these are the buds for the flowers next year, and there are many of these buds every year, but there are almost no blooms.

Natalie

That looks like a reasonable and perfectly healthy Lilac to me.

Only guess would be climatic: do you ever have late frosts or freezes that may kill a swelling Lilac flower bud before it opens? That happens frequently around here. Early warm spells start plant growth, and then one cold night zaps those most tender parts.

Natalie, does your Lilac get any flowers that suddenly died or just didn't open? Mine this year did that and now is declining rapidly.

VirburnumValley, that could very well be the problem, but for the last 9 years, I've had almost no blooms, so that's iffy to me. kwanjin can vouch for the fact that we do get some late frosts here, and even late snow, but I know that hasn't happened every year. I called our friend who rented from us, and he said there were very few blooms on it when he lived here too. So, I'm not really sure what it is. It seems to me though that late frosts would also affect the purple lilac that always blooms like crazy. Maybe the white one is more tender than the purple one? The purple one looks awful compared to the white one, but it sure puts on a nice show every year, especially since it's been in shade for most of it's life!

Maybe it's just stubborn? I love the bush because it looks very healthy to me, and adds a nice patch of green to the area, but I'd rather have one that blooms!

kwanjin, I haven't noticed that problem with mine, but I'll pay better attention to it next Spring. I could have had that happen and just didn't notice it. Do you fertilize yours? I've never fertilized any of mine. I never even thought about doing that! I'm always so busy fussing over other plants that need attention!

I've got two more lilacs that are growing under a very large tree, and they have never bloomed, but I have never expected them to bloom because of the shade. I noticed yesterday that both of them have what appears to be powdery mildew on them. A honeysuckle in the same area also has powdery mildew. Is there something I should do about that? I've never had it on any plants before that I've noticed! I'd hate to lose the plants because they fill the area very nicely, even without blooming.

Natalie

I fertilize everything in the fall with compost. I top dress all around starting in med-September.

You would see the flowers still attached to the stem tips if you had them. It sounds like you don't. I'm at a loss to help you.

kwanjin, I sure wish I was better at making compost with my compost tumbler! I dreamed of having huge amounts of compost, but so far, not so much! I did get enough to put into my daylily seedling bed, which is next to the lilac, so hopefully it's getting some benefit from that. I always keep finely ground mulch under it, which works into the ground over the winter, so it's better than nothing. I always add more in the Spring, so I know it's making the soil good under the bush. I've decided that it's just stubborn!

Natalie

Sounds good to me. LOL

The buds look healthy as does the whole shrub. Let's see what the buds look like in the spring. Even though lilacs don't need a lot of water, they need some, so let's see if the buds are drying up.

Otherwise I would say you just have one of the lilacs that don't bloom much.

Edited to add, before I cut it back to the ground I would try root pruning it, stick a shovel down deep into the ground in a few places around the lilac to get the roots going again.

This message was edited Sep 15, 2011 9:51 PM

pollyk, Thanks for the info. I'm positive that it gets enough water, as I have a sprinkler system, and it gets watered when everything else does. The lilac on the side of the house that blooms a lot doesn't get anywhere close to the amount of water this one gets, so could it be getting too much water? The one on the side of the house usually gets all of it's water from rain, but I do occasionally water it extra if it looks too bad!

How deep do you think the roots are? I've dug pretty deep in the area recently, to make a new bed for my daylily seedlings, and I didn't hit any roots. The bush is very old, so would they be really deep? I may not be able to get a shovel that far into the ground! Also, do you know how far out the root zone would be? When digging the bed for the seedlings, I dug right up to where the foliage is, but didn't dig under the plant.

Natalie

Roots are both deep and shallow, usually. Try going back in under the leaves just a little, and stick your spade down in a few places if you can do that. If you can push it down to the top of the spade part that should be deep enough. Don't go all the way around with the spade, do a spade and then skip a spade, if you know what I'm saying.

I doubt it's getting too much water. Mine get watered regularly, along with Japanese and siberian iris. I think you would notice your buds rotting if that were the case.

Thanks Polly! I'll do that tomorrow. Hopefully it will help, but if it doesn't, no harm done!

I've never noticed the buds rotting, just a lack of flowers, even though I always see lots of buds this time of year. I'm going to keep checking it through the winter though, to see if there is any change that I haven't noticed. It really could be that the buds are rotting and I just haven't noticed it. Hopefully by cutting the roots, something will change! That's about the only thing I haven't done, and I would have never thought to try that. What you said about "do a spade, and then skip a spade" made perfect sense! Luckily it rained yesterday and last night, so it shouldn't be too hard to do!

Natalie

There is an article in the DG database called "Managing Elderly Lilacs" I think, by Toni Leland, that addresses just this type of situation! Look under 'guides and information' then search "lilacs"!

Good luck, Natalie, and if you remember, could you please show us a picture of the buds in the spring, and see if there's anything else we can come up with.

By the way, I've sold lilacs in my nursery for over 20 years, and have around a hundred cultivars myself :) And some are just reluctant bloomers.

carrie, seeing the word "elderly" made me feel rather mushy about that old lilac of mine! I've had feelings of frustration with it, but never anything other than that. Now I'm going to make sure that she's happy in her old age, blooms or not! Thanks so much for letting me know about the article. I can't wait to read it!

polly, I will do my best to remember to get some pictures and post them. Should they look like anything in particular during the winter? Should they still be green? I'm totally clueless when it comes to lilacs! I just appreciate them so much when they bloom, and hate it when they don't! I'm thinking that this one may just be a "reluctant bloomer", like you said.

I had no idea that there were that many cultivars! Your yard must look and smell amazing when they are blooming! I wish the bloom period lasted longer, but I enjoy it while it lasts. I've got quite a few butterfly bush that fill in nicely once the lilacs are done.

I just had a thought, and it's probably a crazy one. You know how some plants flower much better in poor soil, but they are mostly nice foliage with few flowers when the soil is good? Nasturtium comes to mind, but I know that there are many others. Could this be the cause of so few blooms on a lilac? Obviously, the foliage is nice and green and the bush looks very healthy. The one on the side of my house looks horrible in comparison, but is covered in blooms every year. I'm sure that the soil is much better under this one, and not so good around the other one. This one gets regular water, and the other one is lucky if I remember to give it extra water during the hot summer months. It's just a thought, but maybe there is something to it?

Natalie

Possible Natalie, but I doubt it, unless you're really over fertilizing it. Actually mine all get quite a bit of fertilizer, but I'm on sand.

I love that happy in her old age theory. There's a lot to be said about a shrub with the beautiful green leaves your lilac has. After all the bloom is only a short time.

polly, I've never fertilized it before, but I do top dress with finely ground mulch, which does work it's way into the soil. Other than that, I've never done anything to it besides a very mild haircut once every few years.

I agree about it being beautiful and I can live with it. If it looked like the other one, it would have been long gone!

I read that great article that carrie mentioned, and asked the woman what has happened since cutting hers back. She sort of left the story unfinished! I'd love to know how her drastic cutting worked out for her!

Natalie