12 Annual Flowers To Thrive in Full Sunlight

by Ken Lain, the mountain gardener

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 the mountain sun. Some plants love our sun, others faint at the thought. Monsoon humidity can bring an overwhelming mugginess to warm days, and even dry heat can be uncomfortable when the temperatures top 95 degrees F.  People have air conditioning to escape oppressive summer weather, but our plants aren’t so lucky.

Perennials with deep tap roots 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 in producing blooms and buds, and more blooms and buds.

Mandavilla Passion Vine

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 keeps away 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 to the care of all plants.  Any heat-stressed plants attract more insects, pests, and fungal diseases.

Here are my 12 plants choices that will stand up to both heat and humidity. You still will 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. Amaranth is the most widely grown grain in the world. 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 most varieties also make great cut bouquets and dried flowers.

Chili Peppers – These plants generally are not grown for their flowers, but for their spicy to extremely hot peppers.   Most are small and challenging to harvest, but someone noticed how beautiful they are and thought to try them in the flower garden. The shapes of the plants and their pretty blossoms also are fine additions to vegetable gardens.

Cosmos – For cutting flowers, cosmos are about as easy to grow as it gets. You can find them in vibrant, bright shades of pink, purple, orange, red, soft pastels, and even white. The flowers are 2-3″ in diameter and just keep on blooming right through summer.  This flower is sturdy against mountain winds and intermingles well with other summer bloomers. This is another enthusiastic self-seeder, but not to the point of becoming a nuisance.

Cypress Vine – Lantana – Marigolds – Brown Eyed Girl Sunflower

Cypress Vine – Tubular, star-shaped, red flowers, with ferny leaves, make this vine an ornamental climber. It’s in the same family as Morning Glory and grows just about as quickly, reaching 10 – 15 ft. in no time.  This vine will grab onto other plants or a trellis, so make sure to guide it where you want it and secure it with 1/2″ green tie-tapes.

Lantana – For desert blooms through Summer’s heat, Lantana’s fame is wide-spread 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 extremely tough 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 mosquitos around the patio, as well as asparagus beetles, bean beetles, nematodes, and even rabbits!

SunBelievable Brown Eyed Girl Sunflowers  – This jewel for a backyard garden offers amazing summer color with large, vibrant blooms. An award-winning, multi-branching, heat-loving flower, it produces 1,000 flowers in a single season! Sunny yellow petals with a dash of rich red surround the large brown center of each sensational flower. Excellent in borders and containers.

Nierembergia – Cleome – Verbena – Zinnias

Nierembergia – The difficult to spell name, Nierembergia, is from the name of Spanish Jesuit and mystic, 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.

Cleome – Its common name, Spider Flower, is appropriate for the long “legs” that jut out from the blooms. The plants flower from the bottom up, extending the bloom period for weeks.  Cleomes are prodigious self-seeders, but because most are hybrids, you never know what colors will show the following year!  These are tall flowers that branch out, most supporting themselves without staking.

Verbena – Blooming begins early in the season with bright purple flowers that continue well into cool weather.  Several are Arizona natives with leathery foliage that critters find utterly detestable, so plant many where those pesky javelinas roam!

Zinnias – These well-loved plants genuinely love heat. They bloom so quickly, that they are favorites to plant for cut flowers. Cut them and they will bloom again in just days! There’s a zinnia color for everyone, from peppermint stripes, to eye-popping golds, to delicate pastels.

Free Gardening Classes each week at Watters Garden Center ~

July 12, Friday @ 3:30 pm “Planting Juicier Fruits, Grapes, & Berries”  We will have experts on hand that can share the best-producing raspberries, a blackberry bush that produces HUGE berries, table grapes, gooseberries, currants, elderberries, etc. Learn how to grow a garden harvest of big, juicy fruits.

July 20, Saturday @ 9:30 am “Easy Grow Roses”  There are so many different roses to choose from . . . more than our grandmothers ever knew!  Learn the differences between a hybrid tea, a floribunda, a shrub, and a carpet rose. This class is a treasure of information for local gardeners wanting more fragrance & color in their yards.

Until next issue, 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 her web site at WattersGardenCenter.com or  FB.com/WattersGardenCenter.