ISLAND GARDENING 101

INVASIVE SPECIES AWARENESS - 2025

BRAZILIAN PEPPER

If you are a long time resident or visitor to Sanibel, most likely you know about Brazilian pepper. If you are unfamiliar with this infamous plant, here’s what you need to know. Brazilian pepper (Schinus terebinthifolius) is considered a Category I invasive plant by the Florida Exotic Pest Plant Council and is one of the most aggressive, invasive exotic plants in Florida, infesting over 700,000 acres. It’s dense canopy shades out other native species, and it invades the aquatic and terrestrial habitats of the wildlife that depend on the land and water for their survival.

In the 90’s, a City-appointed committee studied habitat issues in conjunction with the development of the Sanibel comprehensive surface water management system. The conclusion was that Sanibel’s wetland habitat had decreased significantly since the 50’s due to fire suppression, Brazilian pepper and other hardwood invasion, and a decreased wet season water table. Thus, in 1996, Sanibel City Council adopted The Brazilian Pepper Eradication Program with a goal to rid the entire island of this invasive exotic plant. Over the years, the Eradication Program, combined with new policies and systems to manage surface water as well as the prescribed burn program, has resulted in the near elimination of this invasive pest. However, it is an ongoing battle. If you are driving around Fort Myers in the winter, and you see beautiful red berries, it is probably Brazilian pepper. As you can imagine, those bright red berries are very attractive to birds and mammals who act as perfect dispersal agents. Thus, Brazilian pepper will continue to be an occasional nuisance. Be vigilant and prevent its spread.

Since plant identification can be challenging, here’s what you should look for: Brazilian pepper is a shrub or small tree which can grow up to 40 feet. There are male and female plants, but only the female bears fruit. The leaves are alternately arranged with 1-2 inch long, elliptic, and finely toothed leaflets. The serrated leaves are reminiscent of the wild rose leaves up north. The mid-rib of the leaf is reddish, and flower clusters which are white and 2-3 inches long, appear from September through November. The fruit is clustered and initially green, becoming bright red when ripe (usually by December). This timeframe distinguishes this non-native plant from native vegetation which generally blooms and bears fruit in the spring through fall. If you crush a leaf of the Brazilian pepper, it smells peppery or like turpentine, but be careful since it is a relative of the poison ivy family, and therefore, its sap can cause an allergic reaction.

In order to successfully control Brazilian pepper, all Brazilian pepper tree stumps MUST be treated with an appropriate herbicide. In most cases, a product containing the active ingredient triclopyr is the best choice for controlling Brazilian pepper; however, the methods of application may vary depending on the maturity of the pepper being treated. Mature trees should be cut as close to the ground as possible. Within 5 minutes, herbicide should be applied to the cambium (living tissue just inside the bark). Small seedlings or re-sprouts may be hand pulled or treated with foliar treatment. Brazilian pepper can be removed from developed property without a permit; however, a vegetation permit is required to remove pepper from a vacant parcel. 

Brazilian pepper made its way to Florida from South America in the mid-1800s and is native to Argentina, Paraguay and Brazil. It was brought here as an ornamental plant, and its brilliant green foliage and bright red berries are often used in Christmas decorations. The introduction of Brazilian pepper to south Florida serves as another cautionary tale of why non-native plant and animal species can be so detrimental to the environment. In 1996, along with the Brazilian Pepper Eradication Program, City Council enacted legislation regulating seven other invasive exotic plant species – air potato, earleaf acacia, exotic inkberry, java plum, lead tree, mother-in-law’s tongue, and Melaleuca. These eight are the worst of the invasive exotics on Sanibel, and may not be intentionally planted or transplanted on Sanibel. When applying for any City Development Permits, conditions of the permit require removal of these eight plants in perpetuity.  

To view pictures of Sanibel’s “worst of the worst” or to view the City’s “The Alien Invasion” brochure, visit the City’s website at: https://www.mysanibel.com/content/download/10568/file/The Alien Invasion 2011.pdf

Contact the City’s Natural Resources Department at (239) 472-3700.

AIR POTATO

One of Florida’s most troublesome invaders is the “air potato”, (Dioscorea bulbifera), a member of the family of the true yams. Air potato, like most yams, is a vine which cannot support its own weight. In order to capture sunlight, the air potato ascends by twining and climbing other plants. Air potato forms dense canopies that can shade out vegetation and cause the collapse of native plants. It can grow up to 70 feet in one season, starting from the previous season’s tubers. These tubers, also referred to as bulbils, closely resemble potatoes, and grow attached to stems. appearing in mid-summer and falling to the ground in late fall when the vines die back. The potatoes lie dormant until the following spring when they sprout and begin the cycle again.

Found in Asia, Africa, and the United States, air potatoes thrive all over Florida which, of course, includes Sanibel Island. Sanibel has included Air Potato on its list of regulated invasive, exotic plants. These plants must be removed when a property is developed, and the property must be maintained free of these invasive exotics in perpetuity.

Unfortunately, air potatoes are extremely difficult to eradicate. Herbicides, such as “Brush-B-Gone”, do temporarily halt the growth of the vine, but they require repeated applications and careful protection of desirable neighboring plants. Hand picking the potatoes and digging up the roots may slow down next year’s vines and crop tubers, but a few missed tubers can mean failure. Do not dispose of potatoes or vines in vegetative waste.

The best hope for stopping this creeping vine, which can quickly suffocate trees and bushes, appears to be a tiny red and black beetle (Liloceris cheni or Lili Beetle) with a voracious appetite for air potato leaves. Since releasing several hundred thousand beetles, Florida has seen a significant reduction in these vines. Beetles are available to residents and municipalities, free, from the Florida Department of Agriculture:

Florida Dept. of Agriculture website:

http://bcrcl.ifas.ufl.edu/airpotatofiles/airpotatoforms.shtml

To view pictures of Sanibel’s “worst of the worst” or to view the City’s “The Alien Invasion” brochure, visit the City’s website at:

https://www.mysanibel.com/content/download/10568/file/The Alien Invasion 2011.pdf

Contact the City’s Natural Resources Department at (239) 472-3700.

NON-NATIVE INKBERRY

The non-native inkberry could cause an invasion in your yard! It is a weedy, fleshy variety, forming dense mounds of shiny green leaves. The white half-flower is followed by a white berry. If planted along the beach, the fruits and seeds may float, which can cause the coastal spread of this salt tolerant species. 

The non-native inkberry can spread extensively, displacing native plants. They are required to be removed from properties to be developed and may not be grown or propagated on Sanibel.  When removing non-native inkberry, small plants may be hand pulled while plants that are cut should treated with the appropriate herbicide to prevent re-growth.

What about planting Native Inkberry?

Planting the low maintenance native inkberry is definitely preferred to using the exotic inkberry! Our native inkberry, Scaevola plumieri, is an erect to trailing, herbaceous evergreen shrub which can grow to four feet in height. These plants often form dense clumps, and the alternate, glossy green, thick leaves cluster near the branch tips.

Native inkberry prefers a dry, sandy habitat and is an ideal plant for the beach zone as it is salt and drought tolerant. The trailing succulent stems help to trap sand and acting as a beach stabilizer. Although, this plant is most often found near the beach, it will grow in a variety of soils. Inkberry tolerates full sun, flowers most of the year, and its dense growth provides excellent shelter for birds and mammals. The small, fan-like, whitish colored flowers with a yellow throat, grow in clusters among the terminal leaves, followed by glossy black fruits eaten by birds.  

To view pictures of Sanibel’s “worst of the worst” or to view the City’s “The Alien Invasion” brochure, visit the City’s website at: https://www.mysanibel.com/content/download/10568/file/The Alien Invasion 2011.pdf

Contact the City’s Natural Resources Department at (239) 472-3700.

Bob Walsh sent these helpful hints in dealing with those pesky Marsh Rabbits. R.S. Walsh is always available to advise you on landscape plants.

Recognize this guy? He’s a Southeastern Lubber Grasshopper and chances are, he’s in your garden. Lubbers are a highly-populated pest living on the islands. They consume vegetation and dine on lilies (particularly Crinum lilies) and bromeliads. They also produce thousands of offspring each year which, in turn, feed on all sorts of delicate plantings. Lubber eggs are laid on the ground near the plants they prefer. When they hatch, the nymphs attack the plant leaves, eating them all the way to the roots. Our Crinum lily was shredded by these lubbers year after year.

While I was on a tour of the beautiful gardens at Sanibel Moorings, Anita Force Marshall, the resort’s former manager of horticulture, addressed the problem. Anita shared her recipe for ridding a garden of these prehistoric-looking grasshoppers.

Save your old coffee grounds in a plastic grocery bag in the refrigerator. When you have accumulated a good amount (about 10 - 15 cups), pour them into a 5-gallon bucket of hot water. Stir the mixture, let the coffee grounds steep and the liquid cool. When lukewarm, pour the entire contents of the bucket (including grounds) all over the plant or plants that being invaded by the lubbers. It is important to soak the ground under and around the plant. In a matter of days, the lubbers will be gone. You might want to follow up with another similar treatment about six weeks later. Lubbers for some reason hate coffee and will avoid a coffee-treated plant.

Our Crinum lily is now flourishing and putting out up to 10 purple and white blooms at a time. We only have to use Anita’s coffee recipe once a year. Who knows? Maybe the caffeine affects the lubbers and gives them the jitters.

Carol Zell

IXORA - Fay Carney

Named after the East Indian deity, Ishwar, this exotic shrub is extremely popular in tropical landscapes. It meets two criteria for plant selection that most gardeners appreciate - minimal maintenance and year-round color. It is also very difficult to kill; it will keep popping up even after you thought you uprooted it!

     There are 562 species of Ixora and five colors -- pink, orange, yellow, red and white. There is even a beautiful variety that is a combination of orange and yellow called Sunset. The leaves are dark green and glossy. The standard Ixora shrub will grow to 10-15 feet tall and 4-6 feet wide, but there are dwarf varieties that only grow to 2-4 feet high. Ixoras flower year-round and can be used as a hedge, a border, or a featured specimen.

     This plant loves the sun, but will tolerate some shade, although it will bloom less under shady conditions. It also loves to be watered frequently. Ixoras prefer acidic soil and will become cholorotic (yellow-leafed) in alkaline soils, although my personal experience is that they are not that fussy. It is recommended that it not be planted next to concrete structures because the run-off from the concrete will make the soil alkaline.

     Ixoras need to be fertilized at least twice a year and should be pruned to shape. Severe pruning is not recommended because Ixoras do not recover well from this condition. In the winter, black spots may appear on the leaves. This is not an indication of a fungus or an insect infestation, so avoid using fungicides or pesticides. This condition is caused by the inability of the plant to uptake phosphorus and potassium because the soil is too cold. There is nothing you can do about this problem; it will resolve itself in the spring when the soil warms up.

     Ixoras may also become the victim of sooty mold which is caused by being attacked by aphids or scale. An insecticidal soap spray will remedy this problem.

     In a nutshell, Ixoras are low-maintenance, high-pay-off plants that are great for snow-birds!