My Hydrangea macrophylla stopped blooming for the last two Summer. The leaves look nice & healthy but it would not bloom at all. Is there anything I should do? By the way, I religiously fertilize my garden with Bloom Booster every two weeks. Other plants bloom nicely.
Thank you.
Help with my Hydrangea macrophylla
What variety is it? If it's a normal variety and blooms on old wood, make sure you don't prune it past say July or you're pruning off the buds for next year (I can prune until August). If it's a cultivar that blooms on new wood, maybe it's not getting enough sun, those types need more sun than the types that bloom on old wood. The real hyd experts (which I am not) will have other ideas, I'm sure.
bbinnj is right about the ones that bloom on old wood, one of the most common reasons for hydrangeas not to bloom is that people prune them too late in the year and accidentally prune off next year's flowers. The other possibility given your zone is that the buds are freezing--H. macrophylla's that bloom on old wood are really better for zones 6 and up, in zone 5 and below it can get too cold and damage the buds, then you won't get blooms the following year. Or you may get a few blooms but not many, or maybe some years you get flowers and some years you don't. If you haven't been pruning them, then this is likely the problem. You can try protecting the plants during the winter and see if that helps, or if you want something that blooms with less trouble, get one of the new H. macrophylla cultivars like Endless Summer that blooms on new wood, then you can prune it when you want and it'll still bloom even if the winter is cold. Or H. arborescens and H. paniculata both bloom on new wood and are more cold tolerant than macrophylla, so you could try one of them too.
If you have a cultivar of H. macrophylla that blooms on old wood, you can protect it for the winter. The website for Nantucket Hydrangeas (I have no affiliation with them but bought most of my hyds there) has info on making winter blankets out of the leaves you'll be raking and garbage bags. I protect mine in zone 6a by covering with a black garbage bag come November, will take it off in March.
ecrane3 & bbinnj: Thank you you both for the advice. I forgot to tell you that I do have an Endless Summer that is about 6 feet from the problematic H. macrophylla.
Endless Summer blooms all summer with no problem at all. I am thinking about moving the problematic H. macrophylla. to a better sunny spot.
Thank you again for your advice.
Make sure you don't move it to a too sunny spot, Endless Summer wants more sun than the cultivars that bloom on old wood only. My Nikko Blue gets western sun and I had to water it twice a day through the summer. It's my first hyd (and being at least 5 years old, it is now massive, too big to move) so I didn't know that putting exactly it where I used to have a holly bush was not the best thing in the world to do.
I really don't think the sunniness of the spot is your problem, I think it's the buds not making it through your winter. Before you do something major like transplanting, I would try bbinnj's suggestion of covering it during the winter first and see if that helps. Unless of course you don't like it in the spot it's in, then feel free to move it but do be careful that it's not getting too much sun. But if you were thinking of moving it just to fix the flowering problem I don't think that's going to really help you.
Ecrane, I just realized that since I planted so many hyds, I have to protect them all!! Hope I can find enough big rocks to anchor the garbage bags.
That's it then. I am going to cover the poor granny with a black garbage bag this winter. Hopefully my dearest neighbor won't call a cop on me. LOL.
Hey you guys, will just a black garbage bag be enough? I have a vareagated hyd. and I was thinking of putting bubble wrap around it and then a tomato cage (it is still pretty small). Think one of you suggested the bb wrap and I thought it was a wonderful idea. Or do you think it would need more air than that?
Jeanette
BTW Ecrane, remember when I used Messenger on my vareagated hyd and the new grrowth came out solid green? Well it changed to vareagated when it got bigger. That plant is still covered with flowers.
Jeanette
Jeanette, where you are you might want to fill some garbage bags with leaves when they fall and make blankets for the hyds, then wrap burlap or another bag around that. Just a bag is OK for me in 6a.
Good idea. Thanks, Jeanette
It is suppose to be 33 Sunday night.
So I did it finally!! Yesterday I covered my H. macrophylla's with a THICK industrial sized contractor bag with bricks anchored down on four corners.
I however did not fill the bag with leaves or make holes on the bag though. Do I really need to do that? Will it be safe and protective enough without? I am in Chicago - Zone 5a.
Thank you for your advice.
This message was edited Nov 13, 2006 11:02 AM
Well, you got yours done but I didn't. Miy variagated and also my Endless Summer really look awful. Don't know if I lost them both.
The literature on the Endless Summer says they do best in Zones 4 - 9 and I am 5 so maybe the tops freeze and they come up from the ground each spring? Sure hope so. I am going to be sick if I lost them.
Jeanette
Your Endless Summer should be OK...the problem with H. macrophylla in zone 5 is that often the flower buds get frozen off and then you get no blooms, but since Endless Summer blooms on new wood you should be fine. I don't know about the variegated one though...if it blooms on old wood you may have lost your flowers for next year (the plant itself should come back though)
Question about the black garbage bag and bricks... doesn't that suffocate the plant? Or heat up too much in the sun? I am a total novice, that's why I ask. I've been researching ways to best protect my macrophylla...I'm also in zone 5. I keep reading conflicting info about what to do to protect those buds. Being a new gardener, I'm just not sure how much air, light, and water a plant needs in the winter months to survive. I've got to decide soon what technique to use...I'm just waiting for my hydrangea to start losing some of it's leaves.
This message was edited Nov 13, 2006 3:43 PM
Jeanette: My Endless Summer is doing fine and blooms nicely with being muched and covered. Though it looks awful right now b/c of the cold, it will come ALIVE again next Summer. That's exactly why they reengineered and came up with Endless Summer.
Noreeaster: It does not sufficate the plant. It protects the plant from the cold. I have NO MORE Sun in Chicago. :-(
Thanks Asunee. I'll get some mulch on it today.
UPDATE: I found an "igloo-like" hole in the mulch as if a mysterious creature has made a home underneth the mulch. As much as I would like to help out the creature, I am afraid it will be eating the branches of Endless Summer. So I covered the hole and put a bunch of mothballs on top.
Am I mean or what?!! :-P
Asunee, put a little Castor Oil around it . They really do not like that. Glad you reminded me. I am going to cover mine today so I will do the same.
Jeanette
Asunee, no, not mean. It'll find a new place to burrow, just not where it might decide that the rootles of your hyd make a good midwinter snack.
Well then, Castor Oil ... Here I come!!
How much do I put it on?
The formula for spraying is 1/2 cup to 2 gallons of water. I would spray the whole surrounding area. Please let us know how it works. The stuff I put on from Gardens Alive worked real well for about 3 months. Probably would have lasted longer if it weren't for the rain. It was a granular that I just broadcast.
Jeanette