I don’t know about where you are, but we’ve entered the hottest part of the summer. August tends to be when we have the highest temperatures of the season. We just finished a week of heat indexes near 110 degrees. This week has been a fluke, with much cooler temperatures and rain(!). Some of our flowering plants have done really well in the hot temperatures, so here’s a list of five (plus one bonus plant) flowers that thrived in the hottest part of the summer 🙂
Lantana
Lantana comes in a variety of colors and it thrives in high temperatures. With a little water when the plant gets really droopy, lantana will grow and bloom throughout the summer. We’ve given our lantanas a little supplemental fertilizer (sometimes a liquid fertilizer when we water them) to keep them in full bloom most of the time.

Lantanas like full sun and do well in almost any soil type. They’re so fuss-free that they are sometimes found growing near long-abandoned home sites, where they were once part of someone’s flower garden. In most of the South, lantanas are perennial. We’ve had our lantanas (in our home landscape – we also used them as nurse plants for propagation) for right at 9 years. The coldest temperature we’ve had during that time is 14 degrees and the lantanas came back that next spring with no issues. We’ve never seen insect pests or diseases on the lantanas.
Besides being pretty and easy to grow, lantanas also attract bees, butterflies, and hummingbirds!
Montbretia
Montbretia (Crocosmia sp.) is a tough flowering plant that does very well with minimal care and high temperatures. A member of the crocus family, montbretia (also called falling stars or coppertips) grows from corms and has brightly-colored blooms that appear in mid-to-late summer. The blooms attract bees, butterflies, and hummingbirds. The plants themselves are winter hardy across much of the U.S, dying back to the ground in winter. The flowers bloom for several weeks over (what seems to be) the hottest part of the summer. In severe drought situations, montbretia will need some water to produce the brightest flowers.

Besides watering during drought, montbretia needs only full sun and soil to consistently produce flowers in the summer. In winter and early spring, montbretia corms can van divided to produce more plants. The plant spreads slowly (in most places) by growth and division of the corms. The corms are easily transplanted in winter.
Crepe myrtles
Crepe myrtles (Lagerstroemia sp.) are flowering trees that are native to India and other parts of southeast Asia. They are one of the South’s most popular landscape trees (Southern Living devotes an entire section of its website to them), with good reason: they’re easy to grow and they bloom when it’s hot. The require little care; they really only need to be watered during droughts. During dry spells, even established trees benefit from watering. We usually fertilize and water our established trees during the heat of summer if there’s no rainfall; this gives us almost continual large bloom clusters over the summer months and into fall. Younger, less established trees definitely need watering during dry summer weather.

Even without fertilizer, crepe myrtles (or crape myrtles or crepemyrtles – whatever your spelling preference) are consistent bloomers that require minimal care. Modern culitvars come in a wide variety of sizes, from short, small shrub-size plants, like Chickasaw, to large tree-sized varieties like Biloxi. They also come in a wide variety of colors – white, lavendar, pale pink, bright pink, red, purple, and every variation in between.
Crepe myrtles don’t require pruning. Many people like to – or think they need to – top crepe myrtle in the winter. It’s best to plant crepe myrtles that are the size you need, since there are SO MANY varieties and options when it comes to tree size. “Pruning” – topping – the trees harms the attractive shape of the tree, plus it’s unnecessary work.
Sunflowers
Sunflowers (Helianthus sp) are annual plants that are often grown as a garden crop. Almost all sunflower species are native to North America, making them an ideal easy garden or landscape plant. The varieties of sunflower grown as a garden crop are grown primarily for their edible seeds. Other types of sunflowers are grown as ornamental landscape plants. Sunflowers are easy to grow from seed and they do well in the summer heat. They will need water during severe drought conditions, but most varieties are moderately drought tolerant.

Several species of sunflowers grow and bloom along roadsides and fence rows throughout the hottest part of the summer; these plants can also be grown in the landscape, where they are virtually maintenance free.
Sunflowers grown for seeds require some minimal fertilization for maximum bloom size. They also to have the soil around them cleared of weeds, especially when they’re younger.
We’ve had fun this year with sunflowers; they’ve been among the easiest plants we’ve grown this summer.
Antique Roses
Antique roses usually do well over the summer. We are especially fond of antique roses, though we also grow and enjoy other types of rose. But when it comes to low maintenance and easy case, antique roses come out on top. Antique roses are older (sometimes MUCH older) rose varieties that grow on their own roots (as opposed to grafted roses). They generally have some disease resistance and they tend to do well with minimal care. Some antique roses were rediscovered after decades – or longer – of growing with human intervention.

Our personal favorite is Alfred Colomb, a variety from 1865, that doesn’t really require any care. We do cut it back when it gets too big, but it could be left with no care for decades and it would continue to grow. It blooms continuously from spring to fall, but the blooms slow down when it gets dry. It continues to bloom, just at a slower pace. It will bloom heavily through the hottest part of the summer if it rains.
Another great antique rose is Marie Daley. It blooms continuously through the summer, as long as it’s watered during dry spells. It will bloom up to the first frost and even during warm spells over winter.
Both Alfred Colomb and Marie Daley are easy to grow and they smell great.
Esperanza
Bonus plant: Esperanza is another great heat-tolerant flowering plant we’ve enjoyed this summer. It’s easy to grow and winter hardy through USDA zone 7. It dies back each winter and grows back again each spring. It starts blooming each summer and usually continues blooming until it gets cooler in the fall. We do keep it watered during dry spells, but otherwise we just let it grow. It’s an easy one – and the butterflies love it!

So what’s your favorite easy summer flower? Let us know! 🙂