9 Annual Flowers To Thrive in Hot Sunlight

If you have a sunny spot in the yard that looks perfect for a flower garden, make sure you choose plants that thrive in the hot sun without a lot of extra care. This can be a bit tricky if you want to grow annual flowers in a mountain garden. Some plants love our sun, others faint at the thought. Dry heat can be uncomfortable when the temperatures top 95 degrees, and monsoon humidity can bring on an overwhelming mugginess.  People have air conditioning to escape oppressive summer weather, but our plants aren’t so lucky.

Perennials with deep taproots and water-conserving leaves tolerate heat and sun better than annuals. Annual flowers never have a chance to develop an extensive root system because they exert most of their energy producing so many flowers.

Choose wisely when planting annual flowers that will have to stand up to hot weather. With dry heat, a little afternoon shade, and a functional layer of Premium Mulch helps sustain most plants and eliminates the need for constant watering. Plants contending with summer heat plus monsoon humidity face a host of additional problems, especially if the heat and moisture persist through the evening hours. These conditions require suitable plants and adjustments in care. Also essential because heat stressed plants attract more insects, pests, and fungal diseases.

Here are my nine plant choices that stand up to both heat and humidity. You still need to keep these favored selections watered regularly, but they won’t faint during the heat of the day or require a lot of additional care.

Amaranth – There are many varieties of amaranth. Some are grown strictly as flowers, some for their leaves, and others for use as a grain. Backyard gardeners love them for their chenille-like blooms and colorful foliage.

Celosia – The flower heads of Celosia are as brilliant as flames in a fire pit. The flowers remain attractive for weeks and make exceptional cut bouquets and dried flowers.

Chili Peppers These plants generally are not grown for their flowers, but for their gently spicy to mouth scorching peppers. Most are small and challenging to harvest, but someone noticed how beautiful they are and thought to try them in her flower garden. The shapes of the plants and their pretty blossoms also are elegant additions.

Lantana – For desert blooms through Summer’s heat, lantana’s fame is widespread. Miss Huff Lantana is the only variety that comes back perennially in the mountains of Arizona. This orange bloomer likes as much sun and heat as she can get! No animals bother or eat lantana, including destructive javelinas.

Marigolds – Because marigolds are so ubiquitous, we don’t give them their due. These are extreme workhorses in mountain gardens. They do best in full sun and prefer being on the dry side. Deadhead spent flowers for endless waves of mop-top blooms well into autumn. An added benefit is their ability to repel mosquitoes around the patio, as well asparagus beetles, bean beetles, nematodes, and even rabbits!

SunBelievable Brown Eyed Girl Sunflowers – This jewel for a backyard garden offers amazing summer colors with large, vibrant blooms. An award-winning, multi-branching, heat-loving flower that produces thousands of flowers in a single season! Bright yellow petals with a dash of rich red surround the large brown center of each sensational flower. Excellent in borders and containers.

Nierembergia – The difficult to spell Nierembergia, comes from the name of Spanish Jesuit, Juan Eusebio Nieremberg. While the name is a mouthful, “Nierembergia” remains more popular than its common name, “Cupflower.” It’s a favorite in containers, but equally at home in the garden, and makes an excellent edging plant.


Verbena – Gorgeous purple flowers cover this summer-long bloomer held over compact green foliage. This bloomer loves bright gardens, summer heat, and grows best in poor soils with less water. The perfect native flower for summer-long performance!

Zinnias – These well-loved plants genuinely love the heat. They bloom so quickly that they are favorites for cutting flower gardeners. Pinch back spent flowers, and they bloom again in just days! There’s a zinnia color for everyone, from peppermint stripes, to eye-popping golds, to delicate pastels.

July Companion Plant is Crape Myrtle

Intense watermelon-pink, solar reds, and LED whites cover this heat-loving bloomer during the late-summer lull in the garden. Use as an accent or as a small scale shield from unattractive views. Plant where you can enjoy close up enjoyment of its beautiful multicolored bark and sinuous branches. The flowers show against forest green foliage that turns red and orange in autumn. Growing to just head height, every yard has room for at least one.  Only available for summer planting.


Free Summer Gardening Classes – Held every Saturday from 9:30 to 10:30 am. Here is the July lineup:

July 18 – Avoid these Common Pests at All Costs

July 25– Privacy Screens and Barriers


Until next week, I’ll be helping local gardeners with sun-loving flowers here at Watters Garden Center.

Ken Lain can be found throughout the week at Watters Garden Center, 1815 W. Iron Springs Rd in Prescott, or contacted through his web site at WattersGardenCenter.com or FB.com/WattersGardenCenter.