Can you recommend annuals that survive a hot Texas Summer?

by Jim Binnings, Collin County Master Gardener
Question of the month: In the Spring I plant annuals that are beautiful for a while but they never make it through the Summer. Can you recommend annuals that survive the hot Texas Summer?
I often wondered why gardeners go to the trouble and expense to plant annuals every year. There are plenty of perennials that would do nicely in a given location. And once established, all a gardener would need to do is keep it trimmed up, water it, and apply an annual fertilizer. One day I was stopped at an intersection looking at the entrance of a subdivision in McKinney when the answer came to me. In front of me was a mass planting of several types of annuals with their colors bright and rich. It gave the subdivision entrance a real “pop” of color and was striking to see. That is why. No other flowering plant can hold a candle to the show put on by a bed of blooming annuals. They produce bright and colorful blooms over a long period of time. They are the king of colorful blooming flowers. Let’s take a closer look at annual flowers.
What exactly is an annual flower? An annual is a plant that must be replanted every year. Annuals complete their life cycle once a year. Sometimes within a season or two. Because the life cycle is at most once a year there is a lot going on inside the plant so it is really important to water, and fertilize it properly. Water on a regular basis. And be sure to water the roots. Learn your plant and recognize when the plant starts to wilt. That is a sigh of moisture stress. Water the plant as soon as possible. Fertilizing is important too. If you use a water-soluble fertilizer, fertilize every time you water your plant. If you are using a granular fertilizer, apply the fertilizer every 4-6 weeks. An occasional soil test will tell you what type of fertilizer you will need to use.
To answer your question about selecting annuals that survive the Texas heat, we have to look no further than the list of annual Texas Superstar® plants developed by Texas A&M AgriLife. This is a list of Texas tough annuals that thrive in the sometimes harsh Texas weather. It isn’t easy to become a Texas Superstar plant. Only the toughest, most reliable and best-looking plants make the cut. Every plant earning the Texas Superstar designation undergoes several years of extensive field trials by Texas A&M AgriLife Research and the Texas A&M AgriLife Extension Service, both part of the Texas A&M System. They must show superior performance under Texas’ tough growing conditions. During the field trials, plants receive minimal soil preparation, reasonable levels of water and no pesticides (Texas Superstar brochure 2020).
Here is the list of the annual Texas Superstars®:
Angelonia Serena Series
Exposure: Full sun Height: 12-18” Bloom time: Summer until frost
Whopper Begonias
Exposure: Partial to full shade Height: 24-30” Planting time: Spring after last frost
Baby’s Breath Euphorbias
Exposure: Full sun Height: 12-18” Bloom time: Summer till frost
Texas Bluebonnets
Exposure: Full sun Height: 12” Bloom time: March through May
Texas Maroon Bluebonnets
Exposure: Full sun Height: 12” Bloom time: March through May
Lady Bird Johnson Royal Blue Bluebonnet
Exposure: Full sun Height: 12” Bloom time: March through May
New Look Celosia
Exposure: Full sun/light shade Height: 10-14” Planting time: After last frost
Blue Daze
Exposure: Full sun Height: 9-18” Planting time: Spring
Cool Season Euphorbias
Exposure: Full sun Height: 12-24” Bloom time: Spring
Gomphrena, Globe Amaranth
Exposure: Full sun Height: 12-48” Planting time: Early spring
‘Allyson’ Mexican Heather
Exposure: Full sun Height: 12-18” Planting time: Spring
Dakota Gold Helenium
Exposure: Full sun Height: 6-8” Planting time: anytime from containers
Larkspur
Exposure: Full sun Height: 36” Bloom time: Spring
Lobularia ‘White Stream’
Exposure: Full sun Height: 4-6” Planting time: Early spring
Rio Series Mandevillas
Exposure: Full sun Height: 24” Planting time: Early summer
Mari-mum
Exposure: Full sun Height: 12” Bloom time: September till frost
Laura Bush Petunia
Exposure: Full sun Height: 24” Bloom time: Spring till frost
Tidal Wave Cherry Petunia
Exposure: Full sun Height: 18-20”
Tidal Wave Red Velour Spreading Petunia
Exposure: Full sun Height: 12-24” Planting time: Late winter, spring
Tidal Wave Silver Petunia
Exposure: Full sun Height: 18-20”
Butterfly Deep Pink Pentas
Exposure: Full sun Height: 24” Bloom time: Spring
Pentas
Exposure: Full sun Height: 24” Planting time: Spring
Pulslane
Exposure: Full sun Height: 4-10” Planting time: Spring
Vinca Cora Series
Exposure: Full sun Height: 14-18” Planting time: Late spring
Fall Zinnias
Exposure: Full sun Height: 12-18” Planting time: Late summer
To learn more about Texas Superstar plants visit the website https://texassuperstar.com/ .
I know what you are thinking. Where are the Marigolds, Periwinkle, Dahlia, Snapdragons, and my new favorite….Cosmos? Yes, there are a few dozen annuals gardeners plant every year that are not on the list above. Remember, we started this conversation looking specifically for Texas tough annuals. Here is an idea for you when you are planning your next annual garden. Plant both Texas Superstar annuals along with your personal favorites. This way if your favorites start to fade a little from the heat, the Texas Superstars will still be there adding good color and keeping your garden looking fresh.
Let us help you with your gardening challenges or questions.
Collin County Master Gardeners Association
Have a question about program or event?