IT WAS HOT, really hot (and will be again, no doubt). There was a bit of visual relief, though: Through any windows that were not covered in heavy curtains against the sun’s heat, it was the white-flowered tough guys of early summer that made the place somehow still look cool and fresh, as wilted as I felt.

I always think of the big panicle hydrangeas, Hydrangea paniculata, as serving this freshening role around August onward, when much of the garden is just too tired. But the trend of summer whites really starts now, with plants like these:

Hydrangea quercifolia ‘Snowflake’

MY FRIENDS at Broken Arrow Nursery recommended I try the oakleaf hydrangea called ‘Snowflake’ (Hydrangea quercifolia ‘Snowflake,’ Zones 5-9), with its distinctive double blooms (detail above). Broken Arrow calls this shrub a “wow” plant because of its foot-long flower trusses, with each individual bloom having extra sepals—hence the double appearance. Best of all, it performs in part shade, and then there is the burgundy fall foliage that this Southeastern U.S. native species is also known for. ‘Snowflake’ gets to 6 feet high by similarly wide.

Clematis fargesii ‘Paul Farges’

THIS IS MY first year of bloom from Clematis fargesii ‘Paul Farges,’ which I was alerted to by my friend Kathy Tracey of Avant Gardens Nursery in Massachusetts. “Looking for the effect of sweet autumn clematis in summer?” she says, and ‘Paul Farges’ (also sold as Summer Snow, Zones 5-9) does make that kind of frothy whiteness happen early. Plus: It is not so invasive as sweet autumn has proven to be. It scrambles to 20 feet or more, but rather than run it up a pergola or other support, I have it scampering through some prostrate ground-covering evergreens on a bank out back, like Microbiota (above) and Cephalotaxus, and soon expect it to run down the wall below them, too.

Aesculus parviflora, bottlebrush buckeye

I ALWAYS have my own legal 4th of July fireworks, courtesy of my biggest shrub of all. At 20 or 25 feet wide and maybe 12 or 15 high, the Southeast native bottlebrush buckeye or Aesculus parviflora colonizes into a big hummocky shape. Skippers (like the silver-spotted skipper nectaring at it, top photo) and butterflies love its foot-long panicles of tubular flowers, and even orioles sometimes visit it to sip here. Great yellow fall color, and sometimes chestnut-like nuts (poisonous to us, but the squirrels seem to enjoy them), are bonuses. Read more about A. parviflora (Zones 4-8)–including an even later-blooming version called ‘Rogers’–in this profile.

Stewartia pseudocamellia, Japanese stewartia

JAPANESE stewartia (Stewartia pseudocamellia, Zones 5-8) is a true multi-season small tree: July flowers with bold yellow centers that look like camellias, peeling cinnamon-colored bark, hot fall color and even a nice silhouette–especially i you choose a specimen that is multi-stemmed, with numerous trunks starting low tot he ground. Though it can reach 40 feet, it is a slow grower and mine is maybe 15 feet after as many years. Don’t bake this one in relentless sun or a dry spot; it seems to enjoy little shade in the hottest part of the summer day, and likes the soil evenly moist (but not sodden). Read more about it in this profile.

American elderberry, Sambucus canadensis

A NATIVE TO Eastern North America and a favorite of pollinators and birds, American elderberry (Sambucus canadensis, Zone 3-9) is a suckering colonizer of a thing. Despite the need to keep it in bounds, I wouldn’t be without a stand of elderberry, a good choice for a medium or even wet spot where it can have its way and not interfere with less-tough neighbors. Mine has grown happily for years in a semi-shady location and flowers and fruits heavily anyhow, at anywhere from about 5 or 6 to 10 or 12 feet tall, depending how you prune it. Missouri Botanical Garden briefly mentions some options in this profile.

Black cohosh, Actaea racemosa (formerly Cimicifuga)

THIS NATIVE North American woodland perennial (Zones 3-8), also called black cohosh or bugbane or snakeroot, is slow to establish, and closely related to baneberry (Actaea rubra), which grows nearby it at my place like kissing cousins. My original three black cohosh plants didn’t seem inclined to naturalize and spread for quite a few years and then suddenly I ended up with a glade of them, their Astilbe-like foliage crowned with sweet-smelling, towering ivory wands throughout July here that appeal to pollinators, too.  Read more about it at this link.

And what about in your garden?

QUESTION: Do you have any relief from white-flowered shrubs, trees or perennials at your place—or any other heat-defying design ideas to share?

  • Highlights of the previous weeks in the 2018 season are archived here.