Annabelle Hydrangea has stunted growth

(Question)

I’ve had an Annabelle Hydrangea in the same location for since 1990. It’s in the shade, under my neighbour’s large maple tree (the neighbour’s yard is three feet higher than mine). I don’t usually water my garden, but Annabelle seems to have been fine until recently. I add compost to the soil every spring, mulch all around, and she is located at the bottom of a gentle slope so does get a bit of water when it rains.

However, this is the third year of stunted growth. The last two years had drought and maybe I should have provided more water. But this year, it has rained frequently (I’m in Toronto) and Annabelle is stunted again.

The plant also had Leaf Tier last year and this year, but I read on this page that the plant doesn’t really suffer much from this (I did remove and destroy all of the leaves that were stuck together like pods).

So, do you think Annabelle needs more time to recover from drought, has lost patience with living with the maple roots, or something else? Until this last three years, it thrived and produced large blooms.

Thanks for any suggestions.

 

(Answer)

 

The last few years have been hard on hydrangeas. From your description, and your success in keeping it around for more than 25 years, it seems as though your plant is in the right spot.  However, this plant likes a lot of water and I expect that may be the reason for the stunted growth over the last couple of years.  While we have had a lot of rain this year, your plant may still be recovering from two years of drought.  As well, it is not a young plant and might benefit from pruning to rejuvenate.  I suggest that you cut it back next spring (the plant flowers in new growth and is typically pruned in the spring) to rejunvenate your plant.

On an ongoing basis you should make sure that your hydrangea is watered regularly, and not rely just on the rain and water running down the slope.  Continue with your practice of mulching to conserve moisture.

It is possible that your Annabelle Hydrangea has root nematodes (very small worms) which can cause stunted growth.  You can check by lifting the root and examining for knobby or enlarged roots are an indication of a grub or nematode at the root of the plant.  As they are very tiny, they can only be conclusively found through soil analysis.  If you have nematodes you can try fertilizing with fish emulsion and lots of compost which should improve your plant’s health and the encourage beneficial fungi which will discourage the nematodes.  If that does not work you may have to replace the plant.

Good luck!