Some hydrangeas need up to two full seasons to overcome transplant shock when planted. There are many reasons at this time that would explain lack of blooms. I have seen hydrangeas bloom in quite shady locations near my sister's house but I am not sure if your "mostly shady spot" is denser and might be causing this problem. So do nothing for now.

Other steps that you can take:

* do not prune in July-August. Flower buds for Spring 2010 develop sometime around then and you do not want to cut them off now.

* do not fertilize in August or later. Too much fertilizer in the soil keeps the plants in growth mode and then winter can kill the non-formant stems/flower buds. One fertilizer application in late June should be good enough for the whole year. Use compost, manure, cottonseed meal or a general purpose slow-release chemical fertilizer (NPK 10-10-10).

* make sure that fertilizer from lawn fertilizer applications does not get into the hydrangea's soil. It is high in nitrogen.

* maintain as constant soil moisture as possible year round(moist not wet). Water in the winter if it is dry and the ground has not frozen. Mulch with 3-4" of mulch thru or a little beyond the drip line. If the plant gets no water when the flower buds are developing or some time after the flower buds have developed, the plant will abort them in a drought.

* a soil test to check pottasium and phosphorus levels might be useful. These minerals help develop roots and blooms as well as general plant well being. You can buy bone meal and phosphate at local nurseries.

* look out for some pests that eat the flower buds (deer, squirrels, etc).

* plant competition could weaken the plant so keep other plants some distance away. This suggestion also promotes good airflow and less of a chance for fungal problems. Do not plant hydrangeas near trees that produce juglone (butternut, black walnut, etc).

Annabelle is one tough plant so I would be surprised if this goes on for more than a season.

As mentioned before, flower buds are being developed now. If you follow those suggestions (no pruning, no fertilzers now, maintain adequate soil moisture, mulch well, etc), you will be removing other possible causes from the list of possibilities.

The only two that would be left are insufficient light or a bad/weak plant speciment that is just unable to bloom.

In the case of insufficient light, you can then transplant or raise the canopy of trees.

In the case of a weak plant, some people use a spade to cut straight down 6-12" inches away from the main stems/crown... You do not have to cut a circle around the plant, just two places or three. Enough to hopefully cut one of the roots. Plants some times react to this type of root pruning by blooming; the reasoning goes that they think they may be injured and they will produce flowers/seed just in case they do not make it.

The only problem I have with that is that I do not understand how the underlying cause of no bloomage is corrected. But some people swear by this so I am passing this as the last thing to try.

Sorry this was so long but I hope it helps,
Luis

Annabelle blooms on new wood, though, so pruning shouldn't knock off any forming buds. Around here they often die to the ground over the winter and still bloom well in the summer.

That is correct. My mistake. Thanks veryzer.

Mine is in it's second year and is full of blooms, in full sun. I would move it.

Are you sure it's an Annabelle? Annabelle blooms on new wood exclusively, and even a young plant should produce a few blooms. I could buy the argument of tranpslant shock/lack of establishment the first year, but not the second - it should be throwing a least a few blooms, she is a very tough plant plant and pretty easy to establish if conditions are met (the major requirement being adequate moisture). She should still bloom in a fair amount of shade.

It's not uncommon for Annabelle to be mislabeled. Total lack of blooms would suggest winter injury to flower buds, which would mean you don't have an Annabelle - in which case, you likely have H. macrophylla.

Oh, but mislabeling never happens mxk3, or does it? Hee hee hee!

My Lowe's Nikko Blue turned out to be.... a lacecap! And a local nursery's Lady Banks Yellow Rose turned out to be a Lady Banks White Rose. And Annabelle is sometimes sold as a wild arborescens but the wild version should be hardy in arbordayle's zone too.

arbordayle, did you ever see blooms confirming that this shrub is an Annabelle? If it is, it should be hardy to around Zone 4 and not casuing these bloomage problems unless you prune as it is getting ready to bloom.

You could settle whether this is Annabelle or not by winter protecting this shrub when you notice that it is going dormant and removing the winter protection 2 weeks or so after your avge date of last frost in Spring. If you get blooms, see if they are Annabelle blooms or mopheads. If mxk3 is right, they will resemble mophead blooms.

Has this mislabeling problem happened to someone else too?

Obviously I have....

I think I'll give it another year. I'll try fertilizing next spring ( I didn't fertilize this year) and thinning the tree canopy a little to let more light in and see what happens. Although purchased from a reputable local nursery, the plant wasn't in bloom when purchased so it's possible I don't have Annabell after all. Thanks for the replies.