Suggestions For Heat Tolerant Annuals That Withstand St. Louis Summers

Sometime soon, weather in St. Louis will return to normal - heat, humidity and haze.  To be successful in the garden, you need to find annuals that can tolerate 95-degree days and blistering sun.  You might think it’s just too much to ask of any flowering plant, but, in reality, there are lots and lots of choices available.  Let me share my list of tried-and-true plant selections with you.

You’ll note that some plants have the words “POM” after their description.  The Missouri Botanical Garden has a program that trials and rates plants on many criteria, naming the best  “Plants of Merit.”  You can be assured that these plants stand up to St. Louis summers and keep on blooming!  You can find more Plants of Merit at www.mobot.org.

The “Supertunia” selection of petunias - these are NOT your grandmother’s petunias.  With names like “Vista Bubblegum Pink,” “Bermuda Beach,” and “Pretty Much Picasso” they are rocking the plant world.  Colors range from pale silver, to bright pink, deep violet and even black. If you or your kids went to Mizzou, you must purchase the new Supertunia “Phantom.”  The flower is black with a gold starburst in the center.  It would do great in a container mixed with Euphorbia ‘Diamond Frost.’  That being said, my next suggestion is…

Euphorbia "Diamond Frost" (POM)  - This workhorse is spectacular in containers or hanging baskets.  The flower is small, and a very bright, white addition wherever you decide to use it.  The diminutive flowers almost look like white confetti sprinkles.  I also use it around my mailbox garden.  It’s low and lush, deer and rabbit resistant and just plain pretty!  It plays well with others and mixes with almost everything in your garden!         

Lantana - The range of colors available in lantana continues to grow each year.  The plant's habit is low, making it perfect for accenting the front of the flower border.  You’ll find pale purple, bright gold, white, and mixes of yellow and pink on the same plant.  They can’t be beat if you’re looking to fill some containers around your pool deck.  Another plus is their deer-resistant nature, along with being hummingbird and butterfly attractors. 

Mexican Petunia (POM) - This plant really doesn’t resemble a petunia at all.  It’s tall, reaching 3 (or more!) feet in the garden.  Bright purple flowers sit atop tall, stick-like foliage.  As summer wears on, this plant really comes into its own.  It gets bushy and the blooms just keep coming.  I like to plant it in my mixed border; it gives height and constant color all season long.  Another plus, it roots readily in a glass of water.  If you like bright colors in your containers, window boxes and borders this is a “must buy!”  As a bonus, it’s a splendid butterfly magnet.   

Melampodium (POM) - The bright gold flowers of  melampodium can’t be beat for the ability to keep on keeping on all summer long.  Small, daisy-like flowers will eventually become a solid mass of color by June. It’s a great front of the border plant and is also deer resistant.  If you’re lucky, you’ll get some of the plants to reseed the next year.  

Coleus - Back in the day, coleus were relegated to the shade garden, looking wimpy and wasted by June.  Not anymore!  Coleus are at home in the sun as well as shade.  The explosion of color available in coleus is truly mind-blowing. From kiwi green to deep red to black, coleus offer something for everyone and a color for every garden.  They mix well in containers, hanging baskets or planted en masse in the garden.  With a regular dose of fertilizer, they will truly be the stars in your garden.  With names like ‘Pink Chaos,’ ‘Pineapple Splash,’ and ‘Sunset strip,’ they’re as much fun to collect as to plant!

Penta (POM) - Penta (commonly called starflower) are somewhat new to nurseries in the states.  They have a full, bushy habit and lovely star-shaped flowers.  They do best in hot and dry situations.  The colors range from clear white, to pale pink, deep pink, red and light purple.  If you’ve got a spot in the garden where nothing seems to grow, I’d advise you to try out a few pentas.  They won’t disappoint and the butterflies and hummingbirds will thank you! 

After you purchase your new plant material, don’t forget to give them a healthy dose of fertilizer.  I suggest using Miracle Gro every 2 to 3 weeks.  You’ll notice a real difference in the amount of blooms produced.