Sudden summer heat has gardeners dancing a seasonal salsa

Adrian Higgins

THE WASHINGTON POST – The hydrangeas that came through the late spring frost unscathed are beginning to bloom.

For many folks, hydrangeas are as timeless and carefree as summer itself. Big, blue or pink mopheads evoke notions of vacation at the beach, the whiff of sun lotion and the dulcet beat of crashing waves.

That’s the ideal, and it may still hold true in more northern, cooler climes. In the Mid-Atlantic, though, the summer garden is a far more complicated affair.

This is because the climate shifts abruptly in June from something temperate to one far more tropical in its heat, humidity and unwillingness to cool off much at night.

It might be that last aspect that is so trying for plant and gardener alike. This climatic dichotomy presents real challenges, because our permanent plantings of hardy plants – including hydrangeas – are driven by their tolerance for winter cold, not summer heat.

One effect of this is that plants that are quintessential summer bloomers in other regions are compressed into our uneasy June zone between spring and summer.

ABOVE & BELOW: Black-eyed Susans have become a standard perennial for the summer garden, though other taller plants, such as the related Rudbeckia maxima, can bring a more interesting look to the dog day landscape; and blazing stars are long-flowering, heat tolerant native perennials for the summer garden, though there are many untapped species to grow, including the late blooming Liatris aspera. PHOTOS: THE WASHINGTON POST

I’m thinking of roses, clematis, lavender and, yes, hydrangeas.

For that reason, I view the flowering of the hydrangeas more as signalling the end of spring than the beginning of summer, even if the faded flower heads remain decorative for months.

The warmth produces the kind of vigorous growth that gardeners in other places can only dream about. European visitors swoon with desire and disbelief at the sight of the hyacinth bean, a purple-leafed vine resplendent in August with striking purple stems, flowers and seedpods.

This would be a feeble thing in the grand palace gardens of France, but in my lowly vegetable garden, it appears automatically from the warming earth and grows quickly.

There are places where tomatoes and peppers must be raised in little home greenhouses. Here, we scramble for a stake or cage large enough to tame the monsters.

So we deal with this heat and humidity. Perhaps the best way to tackle it is to plant a shade tree and wait 20 years, but where’s the instant gratification in that?

As summers seem to have become longer and hotter, gardeners have turned more to using tropical plants so that by midsummer, the deck or patio resembles a dreamy jungle of banana “trees,” cannas, coleus and other leafy exotica.

What was once just something we called elephant ears is now a highfalutin cultivar of alocasia or colocasia, truly stunning in size, leaf venation and sheer presence. I have never grown tired of the Abyssinian banana with its red-tinged stems and leaves. The greater challenge is to find hardy plants that will handle the next few weeks, and this takes some homework. Black-eyed Susans, Russian sage and purple coneflowers are agreeable stalwarts, but they benefit from more inventive company.