Heat-Tolerant Annuals for Local Landscapes

Dear friend,

By the time we reach early June, it feels like the mountains have finally and fully shrugged off that last whisper of spring. The evenings stretch long, the songbirds stay up past their bedtime, and the mornings greet us with a warmth that’s more confident than it was just a few weeks ago. It’s the time of year when everything seems to speed up—plants shoot skyward, pollinators hum in a constant whirl, and we gardeners can barely keep up with the watering can.

This is the part of the season I like to think of as “the proving ground.” Not every plant enjoys the brassy, bold heat of mid-June and July. Some begin to wilt as the sun hits its midday stride, no matter how much you water or how lovingly you mulch. But others—well, they seem to rise to the occasion like they’ve been waiting all year for the curtain to go up.

Heat-tolerant annuals are the unsung heroes of summer landscapes. They may not be as delicate as spring’s violas or as dramatic as early-flowering perennials, but they’ve got staying power, and in a Southern summer, that’s pure gold. These are the plants that don’t just survive the heat—they seem to thrive in it, blooming with confidence even as the sidewalk steams and the clouds of late afternoon thunderheads roll in.

You’ve likely seen them at the local nurseries this time of year—racks full of vincas, petunias, zinnias, salvias, and marigolds. I’ll admit, I have a soft spot for the classics. There’s a reason these plants keep showing up year after year in Southern gardens: they’re tough, they’re beautiful, and they bring pollinators in by the dozens.

Let’s start with one of my all-time favorites: zinnias.

A friend once teased me, saying I must have a zinnia obsession, and I guess it’s true. I plant them every year, and I never regret it. From small, single-flowered varieties to the big, fluffy ‘Benary’s Giants,’ there’s a zinnia for every space. Their bold colors—pinks, oranges, yellows, reds—light up the garden like a box of crayons spilled onto the soil. And more importantly, they just don’t quit. As long as you deadhead them regularly and keep them watered during dry spells, they’ll keep blooming straight through until frost.

They’re also a butterfly magnet. I’ve had whole clouds of swallowtails hover over a stand of zinnias in full sun, and it’s one of the most joyful sights a gardener can witness.

Vinca (Catharanthus roseus) is another stalwart of the summer garden. Not to be confused with periwinkle groundcover, this vinca is an upright annual that thrives in heat and humidity. The flowers look like bright little pinwheels and come in a stunning range of colors—white, blush, bubblegum pink, and even deep burgundy. I’ve seen vinca planted in street medians, beside mailboxes, in dry roadside beds where nothing else seems to grow—and yet, they thrive.

Give vinca full sun, decent soil, and a little room to breathe, and it’ll bloom right through the dog days of summer without so much as a sigh. In fact, overwatering is more of a concern than neglect. Once they’re established, they actually prefer things on the drier side.

Another heat-tolerant favorite that deserves more attention is lantana.

Lantana’s clusters of multi-colored blooms shift and change as they mature, which gives them a dynamic quality throughout the season. You’ll find cultivars in hot oranges and reds, as well as pastel mixes of lavender and yellow. Once established, lantana is impressively drought-tolerant, and the butterflies absolutely adore it.

Now, technically lantana is a tender perennial in the warmer parts of the Southeast, but here in Asheville, we usually treat it as an annual. Still, it gives us an incredible display for months on end, and it does especially well in containers and hot border edges. Just give it sun, and it will reward you.

Coleus, though often thought of as a shade plant, has some varieties that handle sun remarkably well. If you’re gardening in a spot that gets morning sun and afternoon shade—or even filtered sun through trees—sun-tolerant coleus can be a real treat. I love using it to break up blocks of green. The foliage colors range from deep burgundy and lime green to electric magenta and rust, sometimes all on the same leaf.

Pair coleus with sweet potato vine or dusty miller, and you’ve got a gorgeous mix of textures and tones. It’s like composing a visual symphony with plants—letting the foliage tell its own story, even when nothing’s in bloom.

And then there’s salvia, which might just be one of the most underappreciated heat-loving annuals out there.

Annual salvias, such as Salvia splendens, come in striking reds, purples, and blues. Newer cultivars like ‘Mystic Spires Blue’ or ‘Black and Blue’ bring deep jewel tones to the summer garden and offer vertical interest, which is something a lot of hot-weather flowers lack.

Salvias are beloved by hummingbirds and pollinators, and once they’re in the ground and rooted, they’re incredibly resilient. Just give them full sun and decent drainage, and they’ll reward you with a season-long show.

Of course, we can’t talk about heat-loving flowers without tipping our hat to the humble marigold.

Marigolds are so common that some folks overlook them—but not me. I’ve seen marigolds blooming their hearts out in vegetable patches, sidewalk containers, and roadside planters. They’re easy to grow from seed, bloom quickly, and don’t mind the heat. Their scent is distinct—spicy, earthy, grounding. And while the science is mixed on whether they repel pests, they certainly seem to help bring balance to the veggie garden.

A patch of African marigolds (tall, full-flowered varieties) paired with some cherry tomatoes is one of my favorite late-summer combinations. Not only is it beautiful, but it seems to attract every kind of beneficial insect in the neighborhood.

Now, as resilient as these plants are, they still appreciate a good start. Before you tuck them into the ground, give the soil a little love. A scoop or two of compost worked into the top layer can make a world of difference. Water deeply for the first couple of weeks to help roots settle in, then back off and let the plants do their thing.

Mulch around them with straw, bark, or shredded leaves to hold moisture and keep the roots cool. Even the toughest plants will thank you for it—especially during a hot, dry spell when the afternoon sun feels more like a blast furnace than a gentle embrace.

One of the greatest joys of planting heat-tolerant annuals is how reliable they become. They’re like old friends who don’t mind if you miss a phone call or two—they keep showing up, bright and full of cheer, through thick and thin.

They also bring something intangible: a sense of summer. When I walk outside and see a blaze of color from a patch of zinnias, or when I hear a hummingbird zipping toward a stand of salvia, I’m reminded that even in the most sweltering moments, there’s still beauty, movement, and a kind of defiant joy.

And isn’t that what we need sometimes? A garden that laughs in the face of adversity, that leans into the heat and finds a way to flourish? These plants teach us something—about resilience, about thriving in conditions that aren’t always easy, about blooming anyway.

So if you’ve got a full-sun spot that’s been giving you trouble, or if you’re staring at a sun-baked porch in need of life and color, give these heat-lovers a try. Plant a flat of vincas, scatter some zinnia seed, tuck in a few pots of lantana or coleus, and let them show you just how vibrant summer can be.

Until next time, may your garden be full of color, your soil rich and forgiving, and your flowers bold enough to face the sun head-on.

All my best,
Logan

P.S. If you'd like help designing a summer-ready landscape with tough, beautiful plants that can stand up to our Southern sun, visit Unicorn Farm Nursery & Landscaping to schedule a consultation. We’ll help you plant boldly—even in the heat.