I now know Nigra blooms on old wood. But I still can'tmake sense out of it. Interesting that it has bloomed the last several years, with at least one open winter and certainly lows to -5 a couple of those years. The plant gets no protection.

I looked more closely at Nigra, and the majority of the flowers bloomed on side shoots of branches that were pruned back.(I can see the clean stubs where I clipped)What I don't remember is whether I clipped back to a live flower bud or just clipped back to whatever bud was closest to the dead stem.
Someone, please help me out!
Marie

Yes, Nigra blooms on old wood. Flower buds develop sometime around mid-July thru August. Closer to July in the South; in August in the northern half. This is a variable moment and weather affects it so the best you can do is not to prune at all beginning in July. It should be safe to prune after it has bloomed but before the end of June.

Other than the black stems, it does not have any different traits so I do not know why the difference in blooming that you have noticed. Perhaps pruning is cutting the flowering buds, pests are eating the flower buds, the blossom weight is bending the stems downwards, etc. Otherwise, there should be no difference in blooming. Weather and moisture can affect the number of blooms so after this horrible drought here, I expect many flower buds to have been aborted resulting a poor show in Spring 2012.

As far as pruning suggestions, remove all dead wood in late May. Then prune -only if you need to- to remove crossing branches or dead branches. Hydrangeas normally do not need pruning. Although pruning might promote more stems where blooms might come from, the increased weight might make the stems bend more. Deadheading can be done at any time. Again, if you have to prune, do it after blooming but before the end of June.

ejr: let's review what you are saying and see if my practice actually reflects your advice
As soon as the plant leafs out and I can tell what died over the winter, I prune off dead stem tips. This is probably mid-early June. I might prune off or out a really weird stem that spoils the natural shape of shrub

I dead head only if the flowers dry ugly. If they have a nice color and are holding shape, I leave them on.

Otherwise I don't cut on the shrub. Except this summer, now, when those really long flowerless branches were blocking the flowering ones. On one hand, it was a mistake shortening them because the shortened black stems are very obvious. I could have removed the entire stem and avoided the black stub problem, but I'm not sure that would make Nigra look any better.In fact, I'm pretty sure it would have ruined its natural shape.

Am I understanding you to say I can also shape up the plant after it blooms with no loss of next years' blooms? When is spring's "old wood" producing its flower buds? The previous summer? Do branches 2 or 3 or 4 years old continue to produce flower buds?

Thanks to anyone and everyone who can help me understand this seemingly simple concept.

Marie

Hello, Marie. Dried out looking stems CAN leaf out (sometimes they leaf out half way thru only) so it is good to wait a while to give them a chance. Waiting until late May or early June is fine. Alternatively, you can prune them in 1" or 2" increments but stop when you see green or get to the bottom.

You can deadhead at any time that you like. Some people like leaving the blooms thru winter but it is your decision and it does not affect the plant. You can wait until late Spring to deadhead but I find that the blooms will usually disintegrate and fall by then.

Annual pruning (like people do with roses) is not needed provided the shrub is growing in a location where it can grow to size estimated size at maturity without crowding other plants or getting in the way.
Flower buds for Spring 2012 develop between mid-July thru August and stay hidden until Spring. So if you prune now -for example- you could loose Spring 2012 blooms.

Any pruning that you have to do can be done after the plant blooms (so you enjoy the blooms) and before July (so you do not prune off the next year's flower buds). 2/3/4 year old branches continue to produce blooms but winter damage on cold zones (Nigra is hardy only to Zone 6) and moisture problems (between July-Spring) can kill some flower buds so I would never expect a bloom covered bush.

Luis

Here is a link that might be useful: Pruning and Deadheading

Hi, I have been rereading your posts. I know that I am making this far more complicated than it is, but it seems we are talking about two calendar years.If we add the years to our discussion it will be clearer.
August 2011 Nigra blooming
Mid-July through August 2011 flower buds were forming for August 2011 or August 2012 bloom?
Are buds for 2012 being formed concurrent with the August 2011 bloom period?

Removing deadwood (tips winterkilled) can be done in late spring 2012, when it is evident what is dead wood. The buds for summer 2012 blooms will be forming in spring and early summer of 2012 on last year's (201l's) wood.

mt

Hello, Marie. Mid-July through August 2011 flower buds are now forming for Spring 2012 bloom. Mopheads like Nigra, which bloom once a year on old wood, develop their flower buds late in the growing season (July-August) and wait quite a while to bloom. Just like most azaleas and rhododendrons do.

Removing dead wood dried out by winter can be delayed until mid-to-late May to make sure they will or will not leaf out. If you do not want to wait, you can prune in small increments until you hit green or get to the bottom of the stem.

There are no new summer blooms with Nigra. The plant normally blooms once in the Spring and that is it. Those Spring blooms stay on the plant all thru the summer, all thru the Fall and by winter, they have decayed enough that they typically fall on their own. Or you can deadhead them.

Thank you so much. Part of the confusion stems from our zonal differences. You say 'blooming in spring' because your hydrangeas do bloom in spring.
Mine don't bloom until early August. On the other hand, spring doesn't really exist until early-mid april and even here in ma, we not infrequently have a little snow storm April 1. And can have tomato seedling killing frosts until May 1.
Vive la difference!
idabean