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Duckweed with Ducks on the Pond! |
Azola |
Hydrilla |
Alligator Weed in a clump |
Unfortunately, the lake and its basin have a very prominant presence of both aquatic and terrestial (land-based) exotic invasive plants. Exotic means they are not indigenous to our area and invasive means thay take over the landscape. These invasive plants are very difficult to eradicate and efforts by property owners will most likely require an ongoing and continual effort.
The most prominent aquatic invasive plants in the lake are Duckweed, Azola, Hydrilla and Alligator Weed.
Generally spread by wading birds and fed by storm water run-off (pumping high nitrogen content
into the lake from fertilizers), these aquatic plants thrive in shallow water bodies, cover
the surface of non-moving water bodies and create a massive root structure below the surface.
Thus, covered waters severely restrict lakefront access and cause great difficulties for
boaters, skiers and fisherman.
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Duckweed with Ducks on the Pond! |
Azola |
Hydrilla |
Alligator Weed in a clump |
As bad as these aquatic invasives are and their effect on the lake, a far worsening condition
is continuing to develop on the landscape within the basin. Terresterial exoctic invasive
plants are throughout the lake basin, infesting yards and wooded tracts of property. These
plants were generally introduced in landscapes before we understoond their potential dominance.
Generally spread by wildlife eating the berries, these species choak out existing native
vegetation, such as beautyberry and yaupon and completely take over the landscape.
The most prevalent of these exoctics within the Lake Jackson basin are Coral Ardesia, Nandina,
Japanese Climbing Fern, Camphor and Chinese Privet. These plants are illustrated below:
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Coral Ardesia |
Nandina |
Japanese Climbing Fern |
Camphor Tree |
Chinese Privet |
Other terresterial exoctic invasives in the basin that are radidly rooting out native plants are Wild Taro, Chinese Tallow (with wonderful Fall colors, which are exceptional!), Air Pototo, and Kudzu, again, presented below:
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Wild Taro |
Colorful Tallow Tree |
Air Potato |
Kudzu Vine |
In 2007 through 2010, Leon County established a project titled Invasive Exotic Plant Removal
for the Lake Overstreet Tributary to Fords Arm
. This project sought property access from
owners, then dispatched crews to destroy the exoctic invasive plants. This was accomplished by
both sparying and cutting the unwanted species. After leaving time for the invasives to die,
the county then sent in crews to re-plant native specise in the areas where the invasives had
been destroyed. While this project made a significant impact on the invasives along certain
shorelines, the nature of these plants is that property owners need to continue to inspect and
destroy invasives as they re-infect their property. Aquatic invasives continue to plague the
lake.The picture at the right is of a pond on the south shore of Fords Arm, infested with
Azola, Duckweed and Alligator weed.
Exotic invasive plants in Leon County yards is an ever increasing problem. One of the causes
is most home owners do not know what plants are invasive and which are not. Another reason
is some of these plants were used by professional landscapers before their invasive nature was
understood. A third reason is these plants love our soils and climate and reproduce at an
alarming rate. Exotic invasive plants, most of which were brought over to America from parts
of Asia for ornamental purposes, were planted before we understood how they can take over
property, to the exclusion of any native species or non-invasive ornamental. Over the past
several years, in our Florida Friendly Landscape evaluations of Leon County yards, we have
observed some type of exotic invasive in over 60% of the yards we visit.
What are these invaders? Well, let’s start with those prohibited for sale in Florida. These
include Chinese Tallow Tree, Kudzu, Air Potato, Japanese Climbing Fern, Bush Morning Glory
and Cogon Grass. Another group are plants not recommended in Florida Friendly Landscapes by
the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS). These
include Nandina, Coral Ardisia, Campher Trees, Wild Taro, Chinese Privot, Mimosa, Japanese
Honeysuckle, Wysteria and Silverthorn. There is a Leon County ordinance banning the sale of
Nandina domestica (Heavenly Bamboo) and Ardisia crenata (Coral Ardisia). This does little
good, as there are so many invasive plants in the county, they reproduce almost at will.
When dealing with invasive exotics on your property, there are three ways (presented in their
order of effectiveness) to attempt an eradication of these plants:
1) Dig them out – very labor intensive, but highly effective. Using a shovel, carefully
spade around about 8-12” from the plant trunk or stem, then carefully and around the stem, pry
up until the root ball can be lifted free. Remove all excess soil from the root ball.
Dispose of the invasive in a plastic garbage bag, or hang in a tree crotch or in the sun to
dry out and die. If the plant has berries (such as Nandina and Ardesia), take great care to
gather all berries and dispose in a garbage bag. These invasive berries have a very high
germination rate (up to 95%) and can survive in shaded, leafy environments.
2) Cut-and-Paint - The second way is to cut the plant off as close to the ground as is
possible and use a paint brush to immediately (within 30 seconds!) paint the stub with a full
concentration of a Triclopyr-based brush killer. The products we have actually tested with
positive results are: Ortho Max Poison Ivy and Brush Killer, Ferti-Loom Brush Killer and Bayer
Advanced Brush Killer Plus. These three products have the necessary concentration of Triclopyr
(8+%) and have proven effective in Leon county usage. Here is our cut and paint
recommendation for eradication of these invasive species: Have the Triclopyr product (one
of the above) in an open can with a paint brush. Cut the invasive plant as low as you can
reach and then immediately (must be done quickly – we recommend within 30 seconds, but
certainly within 1 minute) paint the Triclopyr product on the stub, very thickly. It takes
about 3 weeks for the product to kill the plant and its root system. Note – this method is
not practical for Japanese Climbing Fern (JCF), as the very small stem and vine makes painting
effectively almost impossible.Place about ˝ inch of full strength Triclopyr-based brush killer
in a flat-sided can then locate the stem emergence from the roots. Cut this stem bundle about
6” from the ground, then Immediately stick the stem bundle coming from the roots into the can
of brush killer. Hold for one minute. After one week, the JCF will show signs of distress and
die in about 3 weeks...
3) Spray Brush Killer - Use a Triclopyr-based brush killer product as a spray on the
foliage and stem structure, which will kill the plant in several weeks. Just follow the
directions for mixing in water on the product package. Care must be taken to have the spray
only fall on the invasive plant. It is recommended that a pump-up type sprayer with a nozzle
that can be adjusted for a fine and direct spray be utilized.
We know one or more of these brush killer products are available at local Tallahassee
nurseries as well as some of the big box stores.
Do not get discouraged, as it likely will take multiple attempts of each method to completely
rid your yard of these invasives. We recommend an initial eradication effort by one of the
methods outlined above, then, follow up with careful inspections during several years after
the initial effort. When any reoccurrence of the invasive is noticed, repeat your selected
eradication method.
Most of these plants are spread by wildlife (Raccoons, Cedar Wax-Wings and Mocking Birds
really like the Nandina and Ardesia berries) or through wind-borne spores. Even if you
successfully eradicate your yard, re-introduction will likely occur from wildlife droppings
or if a neighbor has these plants. Thus, do not be surprised to see invasives re-appear
after you are fairly certain you have removed them. These plants are very resilient and can
even come back from small roots left in the ground or seeds/spores still in the soil. We
recommend an annual inspection (preferable in the dead of winter) to check for intruders.
Only a constant and diligent effort can keep your property invasive free.
For more on invasive plants,click on University of Florida
Center for Aquatic and Invasive Plants.