Heat-Tolerant Dahlias:Keeping Dahlias Happy in the Heat
- Debra Flaming
- Aug 22
- 2 min read
Late August heat can be tough on dahlias, but with a little extra care, these beauties can thrive through the hottest days of summer. Whether you’re growing them in the ground or experimenting with pots on your patio, knowing how to protect your dahlias from stress makes all the difference.
Ground-Grown Dahlias in Hot Weather
Deep, Consistent Watering
In hot conditions, dahlias prefer one or two deep soakings each week rather than light sprinkles. This encourages roots to stretch deeper into the soil, keeping plants cooler and more resilient.
Mulch for Moisture
A 2–3" layer of organic mulch (like shredded leaves, compost, or bark) helps hold soil moisture and lowers surface temperatures around the roots.
Afternoon Shade Helps
In regions where temps soar over 95°F, dahlias will appreciate dappled afternoon shade from nearby trees or a shade cloth. This protects blooms from scorching and extends vase life once cut.
Growing Dahlias in Pots: Risks and Realities
Container gardening can be tempting—especially if you’re short on space—but it comes with extra challenges for dahlias:
Overheating Roots
Pots heat up quickly in the sun. Black or dark-colored containers can act like ovens, cooking delicate tubers and stressing plants.
Water Woes
Potted dahlias need frequent watering, sometimes daily in the heat. Too much water, though, can lead to rot. It’s a tricky balance.
Nutrient Burnout
Dahlias in pots use up nutrients quickly. Without consistent feeding, blooms will be smaller, stems weaker, and plants more vulnerable to stress.
Tip: If you do try container growing, choose large, light-colored pots (at least 5 gallons), add excellent drainage, and feed every two weeks with a balanced fertilizer.
Heat-Tolerant Dahlias from Flaming Acres Dahlias
Some dahlia varieties handle the heat better than others. Here are favorites from our Flaming Acres catalog that stand strong when summer sizzles:
· Chick A Dee – A petite ball dahlia in rich burgundy, compact and resilient even in hot spells.
· Semper Fi – Bold red with patriotic flair, known for its durability.
· Daydreamer – Soft peach-pink tones that hold color beautifully in the heat.
· Barefoot – A playful, relaxed bloomer that doesn’t shy away from hot days.
· Fabulous – True to its name, this variety stays fabulous even in warm conditions.
· Ivanetti – Reliable ball dahlia with velvety burgundy blooms that perform in the heat.
· Tipsy – Quirky and colorful, with strong stems that stand up to summer stress.
· Camano Mordor – A rich burgundy miniature ball with strength and stamina, making it a standout in hot summer gardens.
Sisa – Bright, golden-yellow blooms that thrive when the sun is intense.
Final Thoughts
Dahlias may not love sweltering heat, but with a little extra care, they can still reward you with brilliant color deep into the season. If you’re growing in the ground, think deep water + mulch + afternoon shade. If you’re trying pots, remember the risks and give them plenty of space, drainage, and food.
With the right varieties—and the right care—you’ll keep your dahlias not just alive, but truly happy in the heat.
Debra Flaming
