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.