Richard Bogren, Kirk-Ballard, Heather
LSU AgCenter Horticulturist
(07/26/19) It’s hot out there. And it’s hard to believe summer is drawing to a close. Kids will start back to school in just a few weeks, and football season is so close it is palpable. One thing I get really excited about is the hope of cooler weather and fall plants.
Several plants found blooming in the summertime will carry over into the fall in Louisiana. They include butterfly bush, firebush, Turk’s cap, cassia, angel’s trumpet, salvias and sedums. You can also continue to plant marigolds and zinnias for great fall-flowering bedding plants.
It’s also likely in the fall that many of your warm-season bedding plants, such as periwinkle, blue daze, purslane, scaevola, impatiens and begonias, are still going strong. If that’s the case, leave the beds alone for as long as you can enjoy the display. Once cooler temperatures settle in, it will be time to convert those beds to cool-season plants.
If you don’t already have some of these plants in your landscape, container plants can still be transplanted so you may enjoy these gorgeous fall bloomers. There are some great fall-blooming perennials out there for you to try.
One of my favorites is firebush (Hamelia sp.). Lime sizzler firebush (Hamelia patens Grelmsiz) is both Louisiana Certified and a Louisiana Super Plant. It can be found in most local nurseries. Hummingbirds just love this plant. It has gorgeous orange and red flowers on a yellow-green variegated foliage. This shrub will bloom best in full sun to partial shade, and it will add quiet the sizzle to your landscape.
Turk’s cap (Malvaviscus drummondii) is another great bloomer for the fall. A native plant of North America, it is a root-hardy perennial that may grow year-round in protected areas. Otherwise, it will come back from its roots in the spring. Turk’s cap grows well in full sun to partial-sun. This plant has striking red flowers that never truly unfurl, and the bees, butterflies and hummingbirds just love it. Dark green foliage makes it another striking selection for your landscape beds.
Cassias always come to mind when I think of fall bloomers. The gorgeous yellow flower clusters typically bloom from September to November in Louisiana with a two-to-three-week bloom time.
A few different cassias are commonly grown here. They include Cassia splendida and other cassias known as candlestick plants or candlestick trees, Cassia corymbosa and Cassia alata. You may also see popcorn cassia (Cassia didymobotrya) being sold and grown in Louisiana. All of the cassias tend to be medium-to-large herbaceous and sometimes woody shrubs. They are easy-care plants with few pest and disease problems. They grow best in full to partial sun and are another favorite of pollinators.
Salvias are another great choice for fall flowering plants. Salvia guaranitica varieties Black and Blue and Argentine Skies start flowering in summer and save their best bloom for fall. Some fall-blooming salvias are rosebud sage (Salvia involucrata) and forsythia sage (S. madrensis). Rosebud sage tend to be very large, growing 5 to 7 feet tall and should be planted behind smaller plants in the landscape. Forsythia sage is much smaller. They both grow well in full sun to partial shade, and you guessed it, another great flower for pollinators, including bees, butterflies and hummingbirds.
Angel’s trumpet is another fantastic fall-flowering plant. It’s a tropical plant that will freeze in the wintertime when temperatures drop low enough. But it will come back from the roots each spring and have showy bugle-shaped flowers in late summer through fall. A truly gorgeous addition to the landscape, it comes in all shades of color from yellow, pink, white, purple and orange. Hummingbirds love this plant, too.
Some sedums bloom in fall. One example is Autumn Joy Hylotelephium Herbstsfreude. It has succulent leaves and stems with showy clusters of rosy or copper-to-brown flowers that are just gorgeous for fall. They typically bloom in early summer and again in fall. They perform best in full sun and can tolerate some drought and heat once established.
Marigolds and zinnias also are terrific bedding plants for fall. You can plant both now and enjoy them until freezing temperatures hit.
Marigolds come in a wide range of varieties. African marigolds are taller, larger and can be used as a cut flower. We all recognize the fall primary colors of orange, gold and yellow. French marigolds are the shorter variety, with smaller flowers, and they display more color variations.
Many zinnia species are also available. Traditional, older zinnia varieties are the Zinnia elegans. Some of these varieties are good for cut flowers, like the Benary Giant series. Other varieties that are better as short bedding plants include the Dreamland series.
Both zinnias and marigolds are easy-care, profuse bloomers that love full sun to partial shade. And pollinators love these flowers just as much as we do. Remove faded flowers to encourage new blooms.
And last but certainly not least are chrysanthemums. They have become synonymous with fall, sporting all the gorgeous fall colors. These will be available a bit later in the season and can be used for fall decorating for Halloween or Thanksgiving gatherings. They grow well in containers but can also be grown in landscape areas that get full to partial sun.
Fall is truly an exciting year for so many reasons. I, for one, can’t wait to see all the fall bloomers and catch some football.
Angel trumpet. LSU AgCenter archive photo by Tom Pope
Cassia alata, also known as candlestick tree. LSU AgCenter archive photo by Allen Owings
Turk’s cap. Photo by Randy LaBauve/LSU AgCenter