Question from Margaret S. in Kingston, Ont.
As a loyal follower from issue No. 1, I have come to look on you as my general garden encyclopaedia. However, I have a problem: This year my hitherto lovely hydrangea is quite luscious and green, but not a single flower.
I have been told that it’s lacking phosphate as my composted leaves have produced too much nitrogen and depleted the phosphate. It seems a fine balance. What to do? I dutifully shred all my many leaves — oak and maple — and then allow them to compost. The resulting tilth looks great and I thought I was doing the right thing in digging this into the garden, top dressing or mulching.
I can’t imagine shredded leaves and the resulting crumbly leaf mould would be a problem for your hydrangeas. Leaf mould is full of useful organic matter, and makes an excellent mulch.
Your hydrangeas may not be blooming because they have been pruned at an inappropriate time. Panicle hydrangeas (Hydrangea paniculata) require little, if any, pruning. If you do prune, do so before new growth begins — in late fall or in the very early spring — because flower buds are formed on new wood. If you are referring to smooth hydrangea (Hydrangea arborescens), these respond well to heavier pruning in late winter or very early spring (again, before new growth begins). I cut all stems of my smooth hydrangeas back to about 12 to 18 inches in February or March.
Another cause of reduced bloom may be too much shade. Although hydrangeas tolerate more shade than most flowering shrubs, they do require some sun to produce blooms. Also, hydrangeas like consistently moist soil—they are not drought tolerant.
I hope this information helps, and perhaps your hydrangeas will bounce back next year with lots of blooms. I’m glad to hear you enjoy the magazine. If you still have issue No. 21 (Great Plants to Grow), there is an article by Judith Adam on page 26 about growing panicle hydrangeas.
More articles about hydrangeas:
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