LSU AgCenter's Weekly Message

Plentiful Options for Warm Season Color

Admittedly, I’m more passionate about perennial flowering plants than I am about annuals. I like planting something once and getting a return on investment for multiple years.  However, I think most of us can agree that there is a place for annuals that quickly provide a splash of color – due to their flowers, foliage, or both – in the landscape. (I use the term “annuals,” as although a number of mentioned plants are perennial in their native range, they typically die in the winter here.)

Warm season annuals can be planted after the last expected frost, in a container with potting mix or in a well-prepared in-ground bed. Regardless, make sure that the site is well-drained. Don’t get in too much of a hurry to plant caladiums, as they need warm soil to thrive.

Plants for sunny sites include alternanthera, angelonia, celosias, cleomes, evolvulus, gomphrena, lantanas, marigolds, Mexican sunflower (tithonia), pentas, periwinkles/vincas, porterweeds, portulaca, salvias, sunflowers, ornamental sweetpotatoes, and zinnias. (Some lantanas and salvias are perennial here, but others tend to be annuals.)

Annuals for shadier sites include begonias, caladiums, coleus, impatiens, and torenia (wishbone flower). (While these are traditionally thought of as shade plants, there are now varieties of some of these that are suited to sunny sites, too.)

I’m going to highlight some varieties that have been named Louisiana Super Plants after proving themselves under Louisiana’s growing conditions.

Intenz Classic celosia is one of my favorite annuals. This is a wheat-type celosia with striking flowers that attract an abundance of pollinating insects. I think of the flowers as pink, but some call them purple. Plants grow to approximately 18 inches tall.

Suncredible Yellow and Suncredible Saturn sunflowers branch out and remain more compact than regular, annual sunflowers. They bloom repeatedly until we get a hard frost.

Porterweeds are valued for their nectar production that feeds bees and butterflies, as well as for their colorful flowers. There are red-, pink-, purple-, and blue-flowered varieties. Some grow to 3 to 5 feet tall, while dwarf light blue porterweed grows to about 2 to 2.5 feet.

Impatiens are long-time staples of warm season color for the shade. However, a disease called impatiens downy mildew began affecting plants in Louisiana around 2012. New Guinea impatiens are tolerant or resistant to the disease but have a different appearance from the impatiens to which many people are accustomed. The Beacon series combines resistance to downy mildew with the look of common impatiens. SunPatiens are New Guinea-type impatiens that grow in full sun.

Besides impatiens, torenia or wishbone flower is another option for colorful flowers in the shade. Plants in the Kauai series grow to approximately 8 to 12 inches tall.

Other warm season bedding plants that have been chosen as Louisiana Super Plants include Little Ruby alternanthera, Serenita Raspberry and the Serena series of angelonia, the BabyWing begonia series, Senorita Rosalita cleome, Henna and the FlameThrower series of coleus (ones better suited to full sun than heavy shade), Blue Daze and Blue My Mind evolvulus, the Butterfly and Lucky Star series of pentas, Evolution Violet and Evolution White salvias, and Zesty series zinnias.

Let me know if you have questions.

Click here for previous LSU AgCenter's Weekly Messages

Dr. Mary Helen Ferguson is an Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu or 985-277-1850 (Hammond) or 985-839-7855 (Franklinton).