Learn to Identify Invasive Plants

So many of the plants I grew up around or even some relatively newly introduced adapted species in the nursery trade that have characteristics that I like have unfortunately become troublesome invasive species. These include trees, shrubs and even grasses that have been introduced to the landscape trade or for livestock forage because they appeared to solve a problem, thrive across a variety of gardening zones or just looked pretty. Unfortunately many are now displacing not only native plants but endangering native fauna as well. I have previously written about some of these. Search this blog in the sidebar for “invasive” to find previous posts.

There are a lot of great online resources such as this list of central Texas invasives that will help you identify non-native invasives that may be in your area too. If you are in Texas, the Invaders of Texas program has on-demand online training and has a couple of in person workshops scheduled for later this year that should help you learn to identify invasives as well. For those of you in the DFW area, mark your calendars for a workshop in Arlington on September 27, 2014.

In addition to learning to recognize, avoid and help eliminate invasive species you can help stop the spread of invasives by using caution when adding new plants to your landscape or learning to manage some that you may have so they don’t leave your garden. There are many non-native hybrids available for purchase that have been developed that do not set seed and therefore can’t be distributed to other areas by the wildlife that visit your garden. I have a tree form wisteria that I maintain. I grew up around these lovely plants and am very fond of their spring blooms so I take the time needed to keep it pruned to tree form in a size that allows me to clip off all developing seed pods so it can’t spread.

Many invasive species identification resources such as the one above give alternative, similar native plant suggestions for you to plant if you are unable to find a sterile hybrid or won’t be able to otherwise keep a plant from potentially escaping your gardens. The local flora and fauna will appreciate your efforts to become informed gardeners.

Invasives and the Decline of the Texas Horned Toad

While habitat destruction ranks as the number one reason for loss of species and biodiversity, the invasion of exotic species (aka invasives) ranks number two. When aggressive invasives crowd out a native species it can often have a ripple effect on other native species.

One example of this that has happened while I have lived in Texas is the decline of the Texas horned lizard (aka horned toad). When I was in high school I was lucky enough to see some horned lizards in their native habitat. We also had a large harvester ant nest near the back of the pasture. At the time I didn't know about the link between that ant mound and the horned lizards. The ants didn't cause any trouble though so we left them alone.

Unfortunately, the invasive fire ants did cause trouble for the native harvester ants. They crowded them out and took over their territory. This spelled trouble for the horned lizard. Harvester ants are their main source of food. Isn't any ant as good to eat as another, you may ask? Unfortunately not, or at least not as easy to eat. The way fire ants swarm make them difficult for the horned lizard to make a meal of them without getting harmed. The horned lizard is now a protected species, due in large part, to the ripple effect of invasive fire ants crowding out the horned lizard's main food source, the harvester ant.

While it is unlikely that I will get a chance to spy a horned lizard in my area of Texas anymore, I did get excited that I might have actually seen one a few years ago. I caught a glimpse of a brown, spiky lizard. However as I was trying to remember exactly what a horned lizard looked like from many years before, the lizard turned around and it had a very long tail. Then I knew it wasn't a horned lizard. I did a bit of research and found out that the mystery lizard was a Texas spiny lizard. They are slimmer, not as spiky and have a longer tail than the horned lizard. While I miss seeing those iconic "horny toads", my property seems to have become a haven for the spiny lizard. That is a good thing for me since their diet consists of a wide range of insects.

But I digress, back to the plight of the TX horned lizard and other native plants and animals that suffer at the spread of invasives. You can help by educating yourself about invasives so you don't help them spread and by participating in citizen scientist projects like the Lady Bird Johnson Wildflower Center's Sentinel Pest Network and Invaders of Texas Program that the center partners with.