I had a lot of damage to my hydrangeas last spring and again this spring. I wound up pruning most of them down to about 6-10 inches and they have actually rebounded and I'm getting blooms on them right now. They are stressing during this heat/dry spell and will wilt in the afternoon. Luckily we've had rain the past two nights, but if you don't have regular rain, you must water them at least once a week.

I use organic fertilizers. Not only do they feed the plants, but they help to improve the soil. Miracle grow now makes a new organic fertilizer that they sell in HD. Also if you can in the spring add some composted manure (sold in HD in bags and it does not smell) or mushroom compost. Just dump it on top of the bottom of the plant, you don't have to till it in or anything. This will help the organic activity in the soil around the roots which will help the plant take up nutrients. If you live in fairly new construction, when the builders put in the plantings, they don't do a great job. They simply dig a hole the size of the root ball and drop it in. Many plants just get root bound in their hole and can't spread out roots so they don't grow.

Pruning hydrangeas is tricky. Anything dead should be removed, but if you prune live stuff now, you will lose blooms. Traditionally you prune hydrangeas after they bloom. But if these don't respond, you may want to rejuvinate them by doing a hard prune. You may lost some blooms the first year, but they may begin to grow again after that.

This is a good site for hydrangea info. It may also help you to identify what hydrangeas you have because the pruning is different for different plants:

Hydrangeas Plus

I also ordered a hydrangea from them and it's beautiful. It took 3 years to bloom though.

Hydrangeas have faced a triple threat for more than a year.
A late freeze during Easter weekend, last year. A year long drought, where some of us received only about half of normal rainfall and then a colder than usual winter. Not extremely cold temperatures, but many more hours of lows in the teens and 20's than has been experienced in recent years.
As a consequence, many Hydrangeas experienced tremendous dieback and some didn't make it.
I haven't pruned all of mine that have some foliage and flowers and noticed some of those are now producing foliage on stems that appeared dead. I always check bare stems, by bending them sharply, if dead, they will break. If they still possess live material, they may produce foliage later, but some of the late foliage may not survive, as there may not be sufficient cambium in the stem to support it.
I use only an annual application of compost as a supplement and keep a layer of mulch (leaves, pine straw) over the entire area to preserve moisture. Mulching the entire area around the plants, prevents adjacent dry soil from wicking the moisture away from the plants. I water only when the foliage is wilted in early morning. One or two gallons is usually sufficient. (2 gallons = 1" of water on 3.2 sq.ft.)

Thanks, all of you. I thought Hydrangea were shade plants, but I didn't plant these. I was fortunate enough to inherit a lot of beautiful well-established shrubs and perennials and have enjoyed them.

The stress factor really makes sense when you put all of the contributors from the past year together. I lost about 12-15 azaleas from the drought and 4 established rhododren. It certainly stands to reason that the hydrangea would be affected, although none of my oak leafs were. In fact, they are loaded with blooms this year.

My Lacecap didn't have blooms last year because of the Easter freeze, but it was still huge and flopping over onto our back deck. This year I have some blooms, but it did die back and isn't nearly as large as it was in years past.

My small ones are mostly in shade. They have just never done well since we have lived here. From the looks of them, I just assumed they have never been big so when we moved here, I expected them to grow, at least a little. They are probably responding to the stress from this past year as well, but again, they've never grown.

Again, thank you for your advice; you guys are great!

Beverly

Lacecap, 2006:

Approximate same angle, Lacecap today, 2008:

2006:

2008, same angle:

Small hydrangea, 2008:

Other small, 2008:

With regard to the old wood, when you scratch the bark on the old wood, is it green on the inside? This is a quick sure-fire way to tell if your old wood is still alive.

I have two variegated hydrangeas which look very similar to the ones you have which aren't doing so well, but the rest of mine are actually doing great, even the ones that are getting much more sun this year due to yearly change in the earth/sun rotation patterns. These particular plants have never really done well at all, though. Just tossing it out there in case it's noteworthy.

Is it possible that these plants are in more shade than they used to be? As trees grow, areas that were part sun sometimes become full shade (which hydrangeas won't really like).

Yes, I was going to say that. Hydrangeas like some sun, just not full sun.

I have a mophead that doesnt really seem to be growing all that well either. I planted it next/under a lilac bush to give it some shelter from direct sunlight. I have been told by people to move it, that is what they did to get theirs to grow. But I am confussed because I would think that the one of the first signs of not enough light would be no flowers. It gets like 3 huge flowers every year (had for like 3 yrs). it is kind of funny because it almost seems like there is more flower then plant. Any ideas or experience?

My endless summer won't grow either. I water it, it is in partial shade, blooms but just doesn't grow.