Garden Goons

Gardeners love autumn on the Gulf Coast.  The air is dry and crisp, the bugs are minimal, and the shadows are lengthening.  Time to get out in your garden and peacefully commune with nature.  But are there plants snickering at you behind your back?  Laughing at your feeble attempts to control them?  These are the hoodlums of the garden, and you’d better take care of them before they start a turf war – with you.

Garden Conquistadors

Hundreds of species of weeds are anxious to take hold in your garden, awaiting a helpful bird or breeze to parachute them onto your property.  Many are classified as invasive-exotics, and if you have them in your landscape they should be removed.  Florida has a huge problem with these species running amok because everything seems to thrive here!  The Florida Exotic Pest Plant Council (FLEPPC) produces a list of repeat offenders; you can find this list at http://www.fleppc.org/list/05List.htm.   If you click on the plant name, you can even find images of that species.  Become familiar with these plants so you can spot them when they trespass in your yard.  Replace them with Florida natives as your most environmentally-friendly option.  But be aware that even some natives can out-muscle your other plantings.  Be particularly wary of some of the native vines like Virginia creeper (Parthenocissus quinquefolia), moonflower (Ipomoea alba), trumpet creeper (Campsis radicans), muscadine grape (Vitis rotundifolia), and pepper vine (Ampelopsis arborea).  Great plants for wildlife, but menacing to a landscape if ignored.  Two other natives to keep an eye on are the vining groundcover pink powderpuff (Mimosa strigillosa), and our very own State tree, the cabbage palm (Sabal palmetto).  Hardy cabbage palm seedlings seem to show up everywhere, and they are impervious to standard herbicides.

Trojan Horses

As cool weather coaxes you into your garden, you may get the urge to do some planting.  Planting is always a good thing: adding more green that will absorb solar radiation, slow runoff, and produce oxygen.  Can planting ever be a bad thing?  Yes, if you choose the wrong plant.  Silent invasion is not the only way troublesome plants can get established on your property.  Many arrive as pretty plants in pots, introduced willingly by eager gardeners who plant them only to later realize the monster they have released.  Plants listed in FLEPPC’s Category I are illegal to sell, so you shouldn’t see them available at nurseries.  But think about how these plants came to Florida – brought in by humans, most as ornamentals.  Consider the story of the noxious weed carrotwood (Cupaniopsis anacardioides).  This sturdy, handsome tree from Asia became very popular in the landscape after it was introduced into Sarasota, FL in the late 1960’s.  The lesson is this: today’s ornamentals can become tomorrow’s pests.  Botanical gardens that cultivate exotic plants such as Selby Gardens are very mindful of this potential, and scrutinize their collections closely for weedy tendencies.  Note plants that produce copious amounts of fruits or seeds.  Be concerned about species with a rambunctious habit.  If you can’t contain them, remove them!  Here are some punk plants to avoid when selecting plants for your landscape:

Produce many seeds

Overgrow other plants

Difficult to erradicate

cardboard palm (Zamia furfuracea)

clock vine (Thunbergia grandiflora)

arrowhead vine (Syngonium podophyllum)

coral creeper (Barleria repens)

coral vine (Antigonon leptopus)

asparagus fern (Asparagus densiflorus)

Indian rosewood (Dalbergia sissoo)

Egyptian papyrus (Cyperus papyrus)

Clerodendrum spp.

Jatropha spp.

Indian rubbervine (Cryptostegia madagascariensis)

creeping daisy (Wedelia trilobata)

orange jessamine (Murraya paniculata)

Japanese honeysuckle  (Lonicera japonica)

false shamrock (Oxalis regnellii)

orchid tree (Bauhinia variegata)

jasmine (Jasminum spp.)

Ganges primrose (Asystasia gangetica)

oyster plant (Rhoeo spathacea)

mahoe (Hibiscus tiliaceus)

pothos (Epipremnum aureum)

Philippine violet (Barleria cristata)

passion flower (Passiflora spp.)

running bamboo (Phyllostachys spp.)

Solanum spp.

Rangoon creeper (Quisqualis indica)

snake plant (Sansevieria trifasciata)

umbrella tree (Schefflera actinophylla)

wandering Jew (Tradescantia zebrina)

sword fern (Nephrolepis cordifolia)

wild petunia (Ruellia brittoniana)

wild taro (Colocasia esculenta)

 

Getting the Upper Hand

So how does one run off a rogue plant with a foothold?  It’s no easy task, which is why spotting them before they get big is preferable.  Usually removing them mechanically is the best approach – physically wrestle (cut and dig!) them out.  But in some cases this is simply not feasible, and can be a losing-man’s-game if the scoundrel is the type of plant that will laughingly re-sprout from the roots.  Up the ante with a targeted systemic herbicide application.  Look for products that have the chemical Triclopyr listed as an active ingredient.

Glyphosate (RoundUp) is another systemic that can work, but it was primarily formulated to kill grasses.  These chemicals can be applied to foliage or scored stems in a manner consistent with the product directions, and wear protective clothing.  Remember that these herbicides are non-specific, and drift will kill desirable plants too!  Don’t use gas or oil as it will pollute groundwater and render the soil barren for years to come. 

Now that you know what to look for and how to deal with them, hopefully you can keep those garden thugs on the lam.  And garden in peace again.  Was that a chortle you heard?