UNLEASH YOUR HYDRANGEAS FLOWER POWER!
Secrets of proper care and feeding for your hydrangea
Hydrangeas are full sun to partial shade plants that appreciate moist,
well-drained soil. Lots of organic matter will help here, although the
nicest hydrangeas I’ve seen were all on Nantucket and Martha’s
Vineyard in virtually pure sand; I suspect it’s simply the moist
part that’s important; water copiously. We'll talk about pruning
hydrangeas as well as other factors that affect color, growth
As to feeding, don’t feed new plants until established (1 to 2
months) and then use a balanced fertilizer. Feed sparingly, as too much
nitrogen stops flowering.
The other big question with feeding hydrangeas is flower color. Acid soils
give us blues and baser soils cause pink flowers. The key is aluminum ions
in the soil, so aluminum sulfate is a good quick fix, but prolonged use year
after year may cause a fatal build up in the soil. Iron sulfate is a safer
fix, or try alternating. If pink is what you want, top dress with dolomite
or drench with a quick lime solution.
Failure to flower: frost and late pruning
Hydrangeas fail to flower for several reasons. Most common would be frost damage,
followed very closely by late pruning. Too much shade or nitrogen are other
likely culprits, but lets look at siting our plant and pruning as our best
controls. If your hydrangea is not flowering look at your growing practices
and where you have it planted and make appropriate changes.
Partial shade means more than four (more like six) hours of sunlight.
Finding a more sheltered spot may help. But I suspect that the reason
9 times out of ten is pruning practices. Let’s review….
Incorrect pruning is the biggest downfall of hydrangeas. Too much
pruning and the macrophyllas won’t bloom, too little and the paniculatas become
in Michael Dirr’s words “Monstrosity in the landscape.”
The vine and big leaf types should be pruned immediately after flowering
or not at all! Cut back to a good pair of buds, the last pair if you
want to dwarf the plant back some. The panicle hydrangeas should be pruned
in winter or very early spring and pruned HARD. Selecting 5 to 10 canes
will produce the huge panicles most people are looking for. Besides,
at 15 feet, Pee Gee needs reigning in. Cut it back to that last pair
or two of buds. You’ll be glad you did in 10 years.
Pests and Disease
While the list of diseases (wilt, blight, leafspot, rust) and pests (rose chafer,
scale, mites and nematodes) seems daunting, I would tell you I have never
actually seen any of these, and don’t expect to. I have seen powdery
mildew, but this is easily controlled with benomyl, oil or lime sulfur (the
latter two will discolor blossoms). Generally the biggest problems with this
plant are siting and culture, so find a sheltered, partly shaded spot, water
regularly, and soon your summer and fall will be filled with hydrangeas.
Summer is good
Hydrangeas can be the backbone of most summer borders. Their cultural requirements
lend themselves to combining with roses (in a full sun situation; both need
plenty of water), weigelia, spirea, and any number of other summer flowering
shrubs. Let’s not forget the perennial border; there are any number of
possible combinations there. All in all, hydrangeas are a versatile plant that
deserves a place in your garden.