My Top 10 Summer Annuals

We all know summers can be brutal here in Houston!  I have often been asked how our gardens always look good all summer. That my friends, is because we carefully select the most heat resistant color available on the market.

To begin with, choose the area where you would like to add annuals, remove the mulch, till the soil and add new potting soil as needed.  Add fertilizer, my go-to color fertilizer is Color Star plus fungicide. I apply a generous helping of this on the surface on my prepared bed. Now, we are ready to plant.  Dig a hole twice as wide as the container your plant is sitting in, plants should be about ½” to 1” above soil grade, water in well, and install the mulch around it, be careful as to not smother the little roots in mulch.


Scaevola – This is a wonderful ground cover – I use it as a border or cascading from the edges of pots.  Available colors are white, pink, blue and purple it usually grows about 10-12” tall. It is important to water this plant well until established.

Blue Daze:  Another heat loving annual which can be used along the border.  Grows approximately 10-12” high– with delicate true blue flowers.  Blue Daze is very drought tolerant – I like pairing it with Vinca another drought tolerant annual!  

Cora Vinca:  These are available in both up-right and cascading varieties. Use the upright as an intermediate planting about 12- 15” tall– use the cascading variety as your border or spilling out of pots.  Vincas are very drought tolerant –do not use them in a location that tends to stay wet.  Cora Vincas come in an array of colors, white, peach, strawberry, cherry, magenta, and lilac. 

Portulaca and Purslane:  These are tough plants, especially for areas that do not get enough water.  My favorite varieties are the Purple, Hot Pink Giant Portulaca and the  Double Pink Purslane.  Cinderella Purslane should only be used in pots, as it gets huge and will take over the entire bed if allowed!

Penta Graffiti and Butterfly:  Pentas are my go-to color.  These cheerful Egyptian Star Cluster flowers bloom non-stop in the spring, summer and well into fall.  Penta come in a variety of colors – white, lilac, purple, all shades of pink and red.  Butterfly Pentas grow tall, approximately 20-30”–  so use these as a back row planting.  The Graffiti series grows approximately 12- 18” tall — these can be used either as a back row planting or a middle row. Butterflies love these plants – so include these in your butterfly garden.

Angelonia:  Angelonia is a gorgeous summer annual – these plants bloom spring through the first frost.  There are many varieties of Angelonia growing from 10” to 24” tall.  My favorites are the Serena — 18- 24” tall, and the Serenita – a shorter variety growing about 12” tall. These are available in white, raspberry, pink lavender, blue and purple.

Zinnia Zahara & Zinnia Profusion:  Zinnias are cheerful little flowers that bloom all summer long – for those people looking for yellow, orange or a vivid red flower – these little beauties should satisfy your needs.  They can be used along the border or as a middle row planting as they growing between- 12-15’ tall.  They are also available in shades of pink!

Rudbeckia – Though truly classified as a perennial, in Houston we use some of these bright and cheerful plants as annuals.  My favorite three are the Rudbeckia Toto, Prairie Sun and Indian Summer.

Strap Leaf Caladium:  I love using these plants in my borders—though they do not bloom I consider their foliage a lovely treat in our summer months.  My favorite varieties include White Wing, Florida Sweetheart and Gingerland.

Sun Coleus:  Another plant prized for it’s colorful foliage.  I generally use this for the wonderful combination of color its foliage produces.   This plant is very easy to grow and thrives in most soil conditions. 

I hope these selections have inspired you, get your garden gloves out and let’s get started planting our Summer color! 

Ciao Mardel


  1. Tammy

    Once again Mardel, you fill us up with useful information! Thank you for sharing this. I am a fellow landscape designer and always wonder how your gardens and your designs look so good! Now, if I could only get your style and eye!!

  2. Mavourneen Agius

    Mardel you sure make gardens a place of beauty. Sharing your knowledge makes you a special person.

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