Mid- to late spring is when we start seeing tropical-like plants take off and start growing as we enter our warmest time of year. Instead of summer being a “down time” in the landscape, you can use these plants to enhance your warm-season efforts.
When you get beyond gingers, tropical hibiscus and a few others, most folks may not recognize some of these plants with hot-weather potential. They are available at many independent garden centers around the state, and May through midsummer is generally when they are most-widely available. So consider some of the following examples:
One of the popular fall-flowering plants seen at many retail garden centers in Louisiana during late summer and early fall months are cassias. These plants are now sometimes called sennas. They are a landscape show stopper in October and November. There are three cassias common in local landscapes.
Cassia splendida is usually the tallest-growing — making a 10- to 12-foot-tall tree. Cassia corymbosa is most often a medium-to-large shrub, and the candlestick tree can vary greatly in size depending on age and location in the state. All produce showy yellow flowers.
Pride of Barbados is a great, small-growing tropical tree. You see more of these planted in Houston, San Antonio and Austin, Texas, than you do in Louisiana, but we should use these plants more.
The scientific name of this plant is Caesalpinia. Plants usually are 5 to 8 feet tall by fall and start producing orangey-red flowers on the terminal growth in midsummer. Stems are spiny. Foliage is fernlike. And because this plant is in the legume family, it sets seed pods similar to what you see on beans.
People in south Louisiana should consider white and red flower forms of Texas star hibiscus (Hibiscus coccineaus). They are a hardy perennial, unlike the popular tropical hibiscus. Large five-petal flowers appear in early summer and continue through fall. Plants go dormant in winter and start regrowing from the roots in April. Birds, butterflies and bees are attracted to the flowers.
Cassava is a tropical, shrubby perennial. This plant goes by the scientific name of Manihot. The variegated form is the one you usually see in landscapes and is a personal favorite of mine. This plant thrives in the heat, so plant in a full sun garden. Once again, garden centers easily sell this plant when they have some available.
Alternanthera is what we used to call “Joseph’s coat.” It is typically placed in the warm-season bedding plant foliage category with plants like coleus.
The foliage of most alternantheras is multicolored. The most spectacular of these is the variety Brazilian Red Hot. This plant may be a perennial in protected landscapes in south Louisiana, but in most years it is probably best treated as an annual.
Some alternanthera do best in sun, and some do best in shade, so be sure to check to see which setting your variety prefers.
Copper plants also continue to be popular. The common copper plant in Louisiana is called Louisiana Red.
This variety is known for red foliage on a vigorous-growing plant. Other new copper plant varieties include Bronze, Beyond Paradise, Bourbon Street and Swizzle Scissors.
Similar plants to try include duranta, princess flower (Tibouchina), tricolor hibiscus, purple leaf vitex, ixora, esperanza and more. Check out these plants and see which are available locally.
All of them are great landscape plants for late summer in Louisiana. Keep in mind, however, that if you plant now, you will receive the maximum landscape enjoyment until the first killing frost in late fall or early winter.
LSU AgCenter Master Gardener volunteers will be conducting a Plant Health Care Clinic at Harb’s Oasis nursery on Coursey Boulevard from 9 a.m. to noon Saturday. Get plant questions answered, disease and insect samples identified, and vegetable and landscaping advice. Soil sample kits will be available.
Central Bloomers Garden Club will host its annual plant sale from 8 a.m. to 1 p.m. Saturday at 16524 Quiet Oaks Ave., in Woodland Subdivision in Greenwell Springs.
The Deep South Koi and Pond Society and Harb’s Oasis will host the 13th annual Baton Rouge Area Tour of Ponds and Gardens this coming weekend, 10 a.m. to 5 p.m. Saturday and noon to 6 p.m. Sunday, May 20.
Interact with homeowners and professionals about water features, fish, flowers, plants and outdoor entertainment areas, as you discover the drama that water in motion brings to the home and garden.
Tickets are available at Harb’s Oasis. There is a bus tour on Saturday only. Proceeds from the tour will benefit Brave Heart — Children in Need.
Learn more about the Deep South Koi and Pond Society by visiting http://www.deepsouthkoi.org.
Got a gardening question? Write to Bob Souvestre, horticulturist with the LSU AgCenter, at Burden Center, 4560 Essen Lane, Baton Rouge, LA 70809, or email to email@example.com, or call Master Gardeners at (225) 763-3990.
It is vinca (periwinkle) planting time in Louisiana, Allen Owings, LSU AgCenter horticulturist, reminds us.
This is one of our most popular and widely planted warm-season annuals. We see many varieties and series of vinca used these days. The newer ones have resistance to phytophthora — one of the diseases that is a problem for this bedding plant.
Cora is a seed-propagated series that is genetically resistant, while Nirvana is the vegetatively propagated series that is genetically resistant. Good color range is available across both groups. Plant vinca in full sun and prepare well-drained landscape beds.