While the Florida Panhandle isn’t considered a true tropical climate, now that the summer rains have started, it sure feels tropical outside. To create high performing colorful containers in these conditions, it’s wise to pick plants that hail from tropical climes – one of my favorites is Crossandra (Crossandra infundibuliformis).
Native to tropical Sri Lanka and India, Crossandra is built for hot, humid conditions. An evergreen subshrub growing about 3’ tall in its native range, Crossandra sports glowing orange flower clusters held high on stems that rise above deep green, glossy foliage – a very striking combination. These showy orange flowers arrive once temperatures heat up in the early summer and continue emerging en masse until cool nights stop the show in fall. While deadheading spent flowers can enhance Crossandra’s free-flowering nature, I haven’t found it totally necessary to ensure consistent flowering. In addition to being beautiful, Crossandra’s flower clusters are also attractive to a wide variety of pollinators, including butterflies and dragonflies.
Crossandra growing in partial shade on a patio. Photo courtesy of Daniel Leonard.
Adding to Crossandra’s appeal, the species couldn’t be easier to grow if you give it the right conditions. Crossandra prefers to be sited in areas that receive ample sunlight but also get a reprieve from the hottest afternoon rays. This year, I grew one on a deck that receives sun from about 10 am – 2 pm and is then provided filtered shade from a large tree the rest of the afternoon; these conditions seem to be ideal. Crossandra performs best in moist, well-drained soil, making potting mix an excellent option. Daily watering in the summer combined with our (hopefully) frequent rainfall in July and August keeps it wilt-free. I also apply slow-release fertilizer at planting and then supplement with liquid fertilizer periodically throughout the summer. This, combined with regular irrigation, promotes healthy, vigorous growth, and allows the flower show to continue uninterrupted until cool weather finally draws the curtains.
Crossandra is a versatile plant in container gardens, shining in either the role of filler in larger containers or as a solo specimen plant in its own container. In mixed containers, play off of Crossandra’s orange flowers with partial sun foliage plants like Coleus, Elephant Ears, or Hawaiian Ti, or flowering annuals like Browallia ‘Endless Illumination’, Torenia (Wishbone Flower), Blue Daze, or Purple Heart Plant. While Crossandra does well in mixed containers, as a UF graduate, I prefer to stick it in my favorite blue pot for an orange and blue Gator themed solo container!
Regardless of how you choose to incorporate Crossandra into your garden’s design, it will reward you with summer-long orange flowers in a low-maintenance package. Simply place it in morning to early afternoon sun, give it ample water and adequate fertilizer, and enjoy this Florida Friendly Landscaping approved species. Plant one today!
Plant names in today’s industry are not as simple as the established binomial (genus and specific) and a common name. Many of the plants that you get for your landscape are varieties, cultivars, and hybrids. To make matters more complicated, there are trade names that are given to plants to aid in marketing. We see the Endless Summer® hydrangea or Purple Pixie® Loropetalum. Throw into the mix the work of plant taxonomists who are always reclassifying plants and we can all be truly confused about a plant’s name.
Even as names change, it is still fun to learn plant names. Just recently, I sent plant pictures to the UF Herbarium to help get a clarification on the plant I was calling Georgia savory, Clinopodium sp. This is one of my favorite plants because it makes a spreading groundcover that grows about 1.5 feet tall and has tubular flowers in spring and fall. Many pollinators visit the flowers. It also grows well in sandy, well drained soil and thrives on occasional water. I have a single plant in my backyard that only gets water from rain and has grown to five feet wide over several years. It is definitely a low maintenance beauty.
My results back from the UF Herbarium did not completely clear up this plant’s name. There are reports that it is a hybrid of Clinopodium georgianum × Clinopodium ashei ‘Desi Arnaz’. Other information suggests that it is an intergeneric hybrid between Clinopodium and Conradina named x Clinadina ‘Desi Arnaz’.
The lesson from all this confusion is to just do your best. Realize that all of us can be mistaken on a plant’s name and even those that study plants in depth don’t always agree on a name. In the world of plant names, change can happen.
Many of the Mexican petunia plants, Ruellia simplex, growing in the landscape along the Gulf Coast are covered in white patches. The leaves appear to be growing fur, actual hairs, much denser than the dust of powdery mildew fungus. Excessive development of leaf trichomes, or surface hairs is referred to as erinea. The “fuzz” is the plant’s response to the feeding of eriophyid mites, also called gall mites. These native tiny, microscopic mites feed on the Mexican petunia leaves and stems, causing the plant to produce the white velvety masses. The distorted tissue provides shelter so the mites can continue to feed without being impacted by the weather or contact pesticide applications. Hot, dry conditions favor mite population increases. We have had plenty of that. However, the native mites are not likely to kill the invasive Mexican petunia, so they are not acting as an effective biological control for the plant.
Mexican petunia damage from the eriophyid mite.
Control of this native eriophyid mite begins with heavy foliage removal. Cutting the plants back to just a few inches above the ground removes the infested portion of the plant. The pruned parts need to be placed in a tightly sealed plastic bag before being sent to the landfill. If the location allows burning on-site, that is an even better option. Remember that these mites can feed on many other plants if allowed to escape. They have caused galls in crape myrtle, loropetalum, and hollies, as well as, vectoring diseases like rose rosette.
Then comes the tough decision. If the Mexican petunia is not one of the new sterile cultivars should the new growth be protected as it grows back? If you didn’t plant them or don’t remember what they were called when you purchased them, there is still a way to determine whether they are the invasive Mexican petunia or not. Invasive Mexican petunia produces seed after flowering. Were there any seed pods on the pruned parts? If so, you may consider killing off the entire planting. Several applications of a total vegetation herbicide with surfactant will remove them, leaving you a spot for a new purple flower, maybe a porterweed (Stachytarpheta), verbena or blue salvia.
Blue porterweed can be a substitute for non sterile Ruellia. Photo by Beth Bolles UF IFAS Escambia Extension
If your plants are sterile (have no seed pods), an application of horticultural oil and/or a miticide like abamectin sprayed with each flush of new growth will produce a pretty bed of purple flowers in a short period of time.
The UF/IFAS Extension Northwest District Horticulture Team is excited to announce our third season of Gardening in the Panhandle LIVE! free webinars! Please plan to join us this Spring and Fall for all new episodes where we will tackle gardening issues relevant to the Florida Panhandle!
There are two ways to join the Gardening in the Panhandle LIVE! webinars:
Facebook Live – Follow us on Facebook and follow individual webinar Events.
Zoom Webinar – Pre-registration is required for Zoom. Users must have an authenticated account (free at Zoom Link). Be sure you have security settings up to date to prevent connection delays. Links to Zoom registration will be added to the topic one-two weeks before the webinar and a closed captioned recorded link to YouTube will be available approximately one week after the program. (Underlined words have active links!)
Although we do accept questions from the audience during the broadcast, we may not have time to read them on-air. If you have a great question you think other viewers need to hear, please pre-register through Zoom and submit early!
All webinars are on a Thursday at Noon CDT/ 1:00 p.m. EDT
Looking to add something to brighten your landscape this autumn? Firespike (Odontonema strictum) is a prolific fall bloomer with red tubular flowers that are very popular with hummingbirds and butterflies. Its glossy dark green leaves make an attractive large plant that will grow quite well in dense shade to partial sunlight.
In frost-free areas firespike grows as an evergreen semi-woody shrub, spreads by underground sprouts and enlarging to form a thicket. In zones 8 and 9 it usually dies back to the ground in winter and re-sprouts in spring, producing strikingly beautiful 9-12 inch panicles of crimson flowers beginning at the end of summer and lasting into the winter each year.
Firespike is native to open, semi-forested areas of Central America. It has escaped cultivation and become established in disturbed hammocks throughout peninsular Florida, but hasn’t presented an invasive problem. Here in the panhandle, firespike will remain a tender perennial for most locations. It can be grown on a wide range of moderately fertile, sandy soils and is quite drought tolerant. Firespike may be best utilized in the landscape in a mass planting. Plants can be spaced about 2 feet apart to fill in the area quickly. It is one of only a few flowering plants that give good, red color in a partially shaded site. The lovely flowers make firespike an excellent candidate for the cutting garden and is a “must-have” for southern butterfly and hummingbird gardens. Additional plants can be propagated from firespike by division or cuttings. However, white-tailed deer love firespike too, and will eat the leaves, so be prepared to fence it off from “Bambi”.
