Everything I have read says Hydrangea macrophylla blooms on old wood. I have a three year old Hydrangea macrophylla 130-12-01 ”White Adora”. For the past two springs it sent up new leaves in the spring from the ground (new growth). Zero growth at all on the old wood. In fact, the old wood is completely dry and snaps cleanly in half. It looks dead to me. It has not bloomed since the first year I had it (when it was in bloom at the garden centre).
Advice gratefully accepted.
I’m not sure why your hydrangea has not bloomed for 2 years. Consider whether it’s in a good location and getting enough light, water and nutrients. The plant needs full sun – especially morning sun, if possible, and lots of water, and should be planted in well-draining soil. The soil should remain moist and not be allowed to dry out. Too much shade will decrease the number flowers that appear. Also, if you are using a fertilizer with too much nitrogen, this will encourage green leaves, but not flowers. Fertilizers that are higher in phosphorus should promote growth of blooms. Harsh winters and cold spring temperatures can also contribute to bud damage; to protect the plant, wrapping it with burlap over the winter may help the buds survive.
Older cultivars of Hydrangea macrophylla, or bigleaf hydrangea, bloom on old wood (i.e., they set flower buds from late summer to early autumn, the the year prior to blooming), although newer cultivars bloom on both old and new wood – i.e., on both last year’s and the current season’s growth. There is very little information about Hydrangea macrophylla White Adora (also called “White Adore”) online. It is a cultivar named ‘Schroll 130-12-01’. Schroll (in Denmark) are hydrangea breeders and I believe that yours is a relatively recent cultivar, so may bloom on both old and new wood – but I was unable to verify this online (the School website is in Danish!). The White Adore Hydrangea is considered very small and it should bloom earlier than other bigleaf hydrangeas – it’s considered well-suited for pots.
In any event, it is important to prune any dead wood away in the spring. Check whether a stem is dead by scraping your fingernail or a sharp knife into the bark of the stem – if you see some green, the branch is still alive. Also, look for buds that are swelling and this would also mean the plant is alive. If the stem is dead, prune it out completely. If only part of the stem has died, prune it back to the point where you see live growth.
If you have been pruning between the fall and late spring, you may be inadvertently getting rid of the growth on the old wood that would have turned into blooms. It’s best to prune in the summer (this is after the blooms that should have appeared would have faded), before the autumn arrives.
See a previous post on the Ask a Master Gardener website: Non-blooming hydrangeas. This explains that if old wood has died and your plant indeed blooms on old wood, then there won’t be any blooms until the following year.
I’d suggest that you take some photos of the hydrangea and speak with someone at the garden centre where you purchased the plant, to see if they have any advice for you.
May 31 2021