Take a look at your hydrangeas this week. The blooms that were a clean blue or bright pink back in July have probably turned into something stranger and honestly more interesting, with green creeping in at the edges and hints of burgundy across the sepals. A lot of people read this as the plant fading and start reaching for the pruners. It isn’t fading. This is the best stage your hydrangea will hit all year, and it happens to be the only stage where the blooms will dry properly.
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Why Your Blooms Are Changing Color
As a hydrangea bloom matures, the sepals stop putting energy into their fresh summer pigment and start developing the muted greens, roses, and deep wines that show up in late August and September. It’s the same plant, just further along in its cycle.
The practical upside is that these mature blooms have thicker, papery sepals that hold their shape and hold their colour. A June bloom is soft and full of water. An August bloom has already done most of the drying work for you while still attached to the plant, which is exactly why florists wait for this window.
Pink, Blue, and the Soil Underneath
This is a separate thing from the antique shift, and the two get mixed up constantly.
Summerhill Landscape Hydrangeas can bloom anywhere from pink to blue depending on how much aluminum the plant is able to pull out of your soil, and that availability comes down to soil pH. More acidic soil frees up aluminum and pushes blooms toward blue. More alkaline soil locks it away and you get pink. Two identical plants in two different beds in the same yard can genuinely come out different colors.
If you want to shift yours, though, now is not the moment. Changing soil pH is a slow, season-long project, and anything you apply in late August won’t show up in the blooms until well into next year. Make a note, and start in spring.
Cutting Hydrangeas: Late Summer Is the Sweet Spot
If you’ve ever cut hydrangeas for a vase in early summer and watched them collapse within a day, this is why. Young blooms are full of moisture and wilt almost immediately. Mature late-season blooms are far more cooperative.
Squeeze a bloom before you cut. If it feels soft and fleshy, leave it a while longer. If it feels slightly papery and firm, it’s ready. Cut in the morning while the plant is fully hydrated, take a decent length of stem, and strip off the lower leaves so nothing sits below the waterline. Cut on an angle and get the stems into water quickly.
How to Dry Hydrangea Blooms
The easiest method is also the best one, and it barely qualifies as a method. Put your cut stems in a vase with about two inches of water, set them somewhere out of direct sun, and then simply leave them alone. As the water evaporates the blooms dry gradually, and that slow pace is what keeps the sepals from shriveling. You don’t need to top the water up. In a couple of weeks you’ll have dried blooms that last for months.
If you’d rather hang them, bundle a few stems loosely and hang them upside down somewhere dark and dry with decent air circulation. This works fine, though colors tend to hold a little better with the vase method.
A few things worth knowing either way: dried hydrangeas are fragile, so handle them by the stem rather than the head. Keep them out of direct sun, since it will bleach the color out over time. And expect some variation, because no two heads dry to quite the same shade.
The Pruning Mistake to Avoid Right Now
Here’s where a well-meaning fall cleanup goes wrong. Your hydrangea is setting next summer’s flower buds on its existing stems right now, during late summer and into fall. Those buds sit there through winter and open next season. If you cut the plant back this month to tidy it up, you’re cutting off next year’s flowers, and you won’t find out until the following July when nothing blooms.
This is why Fernlea recommends pruning your Summerhill Hydrangeas in spring. Waiting lets you see exactly what came through the winter, shape the plant without guessing, and keep the buds it spent all autumn producing.
Removing individual spent blooms is fine, since that’s just cutting for the vase by another name. Snip right below the flower head and stay well clear of the buds further down the stem. What you want to avoid is any hard cutback of the plant’s structure.
What Your Hydrangeas Need Through September
Watering matters more than people expect this late in the year. Hydrangeas are thirsty plants with shallow roots, and September can still bring dry stretches. A plant that goes into fall drought-stressed, heads into winter in poor shape, so keep the soil consistently moist even as the weather cools off.
Feeding, on the other hand, should stop. A late dose of fertilizer pushes out soft new growth right when the plant needs to be slowing down and getting ready for dormancy, and that tender growth is the first thing damaged by frost. Let the plant wind down on its own schedule.
Otherwise, leave it be. The foliage will yellow and drop on its own, and that’s the plant doing exactly what it should.
Enjoy the Best Weeks of the Year
The stretch between now and first frost is the most rewarding part of the hydrangea season, as long as you resist tidying it away. Cut generously for the vase, dry a few heads for the winter months, keep the water up, and save the pruning for spring.
Want to know more about growing them? Visit our Summerhill Hydrangeas page, or find a Fernlea retailer near you. Happy planting!