Invasive Plants May Be Creeping Closer

What are invasive plants?

Wikipedia's definition applies to non-indigenous species, or "non-native" plants that adversely affect the habitats and bioregions they invade economically, environmentally, and/or ecologically. They disrupt by dominating a region, wilderness areas, particular habitats, and/or wildland-urban interface land from loss of natural controls (i.e. predators or herbivores). This includes non-native invasive plant species labeled as exotic pest plants and invasive exotics, in restoration parlance, growing in native plant communities.

The kudzu vine is one we have commonly heard of taking over areas of the southern states. So far the St. Louis region has not had this as a problem but we do have many invasive plants growing all around us.

One of these is the Japanese honeysuckle shrub. Japanese honeysuckle invades a variety of habitats including forest floors, canopies, roadsides, wetlands, and disturbed areas. Japanese honeysuckle can girdle small saplings by twining around them, and it can form dense mats in the canopies of trees, shading everything below.

A native of eastern Asia, it was first introduced into North America in 1806 in Long island, NY. Japanese honeysuckle has been planted widely throughout the United States as an ornamental, for erosion control, and for wildlife habitat. It has beautiful and sweetly fragrant flowers every spring then becomes covered with bright red or black berries in fall which the birds love to eat.

If you look into wooded areas, there are shrubs growing up to seven feet tall just now leafing out. Drive down Dauphine toward Highway 40 and look right up into the hill side. All of these shrubs are honeysuckle. They take over everywhere. Not just in wooded areas but in yards, gardens, and cracks in cement.

These should be removed and this is one reason. There are perennials, such as Trilliams, Anemonies, Celandine and Bleeding Heart just to name a few, that grow only in very early springtime when sunlight shines onto the woodland floor. When the leaves on the overhead canppy fill in and shade, these perennials have finished their blooming and fruiting and are ready to die back to go dormant until next spring. Honeysuckle leafs out earlier than most natives and blocks the sunlight to the forest floor and thus keeps these perennials from ever seeing sunlight to promote growth. They may not necessarily die but remain dormant in the soil until sunlight breaks through once again.

This is where we come in. One pretty reliable method of removing honeysuckle is to work in teams of two people. One person cuts the shrub approximately four inches above ground.  The second person follows close behind, using a bucket with a chemical that contains the active ingredient glyphosate (like Round Up) with a bright color dye added.  Use a paint brush to paint each newly-cut stump with the chemical, being careful not to splash it on any other plant.

Any time is a good time to remove honeysickle but probably the best time is in late fall. This shrub holds onto its leaves later than other shrubs so it is easy to locate. Fall is when sugars and nutrients that have been produced all summer are now moving down into the roots for winter storage. Because of this downward movement the chemical will be pulled into the root area fairly quickly and begin to kill the roots. This is an on-going eradication because birds that eat the berries from another location will drop the seeds everywhere.

Another plant becomeing invasive is the ornamental pear tree. No doubt this past week you have noticed many white flowering trees growing in roadside ditches and at the edges of woodlands. It was thought that the cultivars of pear, such as "Bradford" were sterile and would not reproduce, but we are finding that with the addition of newer cultivars like "Aritstrocrat" and "Cleveland Select," the trees are cross pollinating to where the seeds are no longer sterile.

What do do? Eradicate existing trees in the ditches with the same method as for honeysuckle. Be sleective when buying pear trees. Ask if they are sterile and don't plant as many. We've learned in the past few years that these trees are not very strong in high wind storms and break easily. I always recommend planting a variety of trees for both aesthetics and functionality. Often what affects one type of tree may not affect another. If there is a disturbance, like a disease, that affects only pines, but not spruces it will affect all the pines and devastate your landscape. So just like your financial portfolio, diversify your landscape.

If you have a beautifully landscaped yard or have unique garden ornaments that you are proud of and would like to see featured on Lake Saint Louis Patch, contact me at Bahrmasel@msn.com