Removing Invasive Plants
Are any of these invaders still cluttering your yard?
For many gardeners, their yard is their sanctuary. It's a place of peace and quiet in a busy world. Unfortunately, there may be trouble in paradise. Invasive plants are more than a threat to our ecosystem and economy. They're a threat to the tranquility of our landscapes.
In the world of horticulture, many invasive species begin as landscape favorites. That fabulous filler shrub may fill your garden, inch by inch and then row by row. Suddenly it's in your neighbor's yard, too! Worse still, over time they crowd out native species. This deprives native wildlife, like birds, bees, and butterflies, of food and shelter.
In the last 100 years over 50,000 plant and animal species have been brought to and established in the United States. About one in seven becomes invasive. Countless ornamentals listed as invasive are still in production, found wherever garden supplies are sold. They're attractive, and they don't come with warning labels or caution signs. So what's a gardener to do?
Take these three steps to remove problem species and restore tranquility to your garden: research, remove, and replace.
Step 1: Research
Before you pull out, share, or purchase a plant, always do your research. The University of Florida IFAS Assessment of Non-Native Plants in Florida's Natural Areas is an excellent resource for checking a plant's invasive status. The assessment includes pictures to help you identify the plant in question. The information is specific to North, Central, and South Florida.
But what about the anonymous plants in your garden? Sometimes even plant ID experts have trouble identifying a species. Other times it's been there so long you've forgotten a plant's name.
In these cases your best option is to contact your local Extension office for help identifying the plant.
Step 2: Remove
Once you've identified a problem species, it's time to remove it. With invasive species, this is often a challenge; they are, by nature, hard to remove. Generally, mechanical control methods (like pulling out the plant) should be tried before chemical control is attempted. Be sure to bag all plant debris and dispose of them in the regular, landfill trash. This keeps cuttings and seeds from establishing elsewhere.
Many tough ground-cover species can be difficult to remove by hand. In these cases, save your strength and let the sun kill them instead. In the hotter months of the year, cover the area with clear plastic. Then just bury the edges to keep it secure, and wait. This process, called soil solarization, is simple and inexpensive. After six weeks the plants underneath should be well and truly dead. Prolonged periods of cloudy weather may mean extending the treatment period, however.
In extreme cases, a targeted application of herbicides may be necessary. Stumps of trees, for example, should always be treated with an appropriate herbicide to prevent regrowth.
Before applying a pesticide of any kind, it is important to educate yourself. Irreversible damage to your landscape is possible. Some herbicides are also toxic to humans. Reading and following all label instructions is required by law. Consult the Florida Homeowner Herbicide Guide for more information.
Do I really need to remove them?
One popular argument against removing problem species is that they are "well-maintained." Unfortunately, even when taking the utmost caution, an invasive in your yard can still spread. Some seeds may scatter in the wind. Birds can eat berries and then drop the seeds as they fly. The clippings might make it into storm drains and germinate hundreds of miles away. Invasive species cannot be managed perfectly, and all it takes is one escaped individual.
Please choose to remove invasive species. Your pet plant may be the next killer kudzu, monster hydrilla, or Brazilian pepper-tree. Early interventions are key when it comes to invasive ornamentals. While they're contained in your landscape there is hope, and it's in your hands.
Step 3: Replace
Once an invasive is removed, it's time to fill the hole. One fantastic resource for choosing replacement plants is the article series Alternatives to Invasive Plants Commonly Found in Florida Landscapes. These articles are region specific for North, Central, and South Florida. Each suggests dozens of replacements that deliver similar aesthetics to common invasive plants. Gardeners can choose from native species, non-invasive non-natives, and even sterile (non-fruiting) varieties. Many alternatives were bred right here at the University of Florida.
Lantana, for example, is a very popular landscape plant. Unfortunately, it is also listed as invasive in North, Central, and South Florida. The article linked above offers native replacement options, like beach sunflower, pineland lantana, and tropical sage. Also listed are a number of non-native but landscape-safe substitutes: African bush daisy, blue daze, rose, and autumn or scarlet sage.
But for gardeners reluctant to lose their lantana, there is a third option: a sterile variety. Recently the University of Florida has released three sterile varieties of lantana: 'Bloomify™ Red', 'Bloomify™ Rose', and 'Luscious® Royale Red Zone™'. More are in production and coming soon.
Below is a list of some common invasive ornamentals still occasionally shared or found for sale. To learn more about these, and alternatives to the other plants on the list above, consult the article series on Alternatives to Invasive Plants linked at the bottom of this page.
Commonly Found Invasives
- Australian umbrella tree, octopus tree, Queensland umbrella tree (Schefflera actinophylla)
- Beach naupaka, half-flower, scaevola (Scaevola taccada var. sericea)
- Camphor tree (Cinnamomum camphora)
- Chinese privet (Ligustrum sinense)
- Chinese tallow tree, popcorn tree (Triadica sebifera, syn. Sapium sebiferum)
- Chinese wisteria (Wisteria sinensis)
- Christmas senna, Christmas cassia, climbing cassia (Senna pendula var. glabrata)
- Coral ardisia (Ardisia crenata)
- Elephant ear, wild taro (Colocasia esculenta)
- Gold coast jasmine (Jasminum dichotomum)
- Jambolan, Java plum (Syzygium cumini)
- Japanese bishopwood (Bischofia javanica)
- Japanese honeysuckle (Lonicera japonica)
- Lantana, shrub verbena (Lantana camara)
- Melaleuca, paper bark, punk tree (Melaleuca quinquenervia)
- Mexican petunia (Ruellia simplex)
- Mimosa, Silk tree (Albizia julibrissin)
- Mountain ebony, orchid tree (Bauhinia variegata)
- Nandina, heavenly bamboo (Nandina domestica)
- Sea hibiscus, mahoe (Talipariti tiliaceum)
- Strawberry guava (Psidium cattleianum)
- Surinam cherry (Eugenia uniflora)
- Wedelia (Sphagneticola trilobata)
For help identifying landscape species and safely removing invasive species, contact your local extension office.
Also on Gardening Solutions
- Alternatives to Invasive Plants Commonly Found in South Florida Landscapes
- Alternatives to Invasive Plants Commonly Found in Central Florida Landscapes
- Alternatives to Invasive Plants Commonly Found in North Florida Landscapes
- Help Protect Florida's Natural Areas from Non-native Invasive Plants
- The UF/IFAS Assessment of Nonnative Plants in Florida's Natural Areas: History, Purpose, and Use