Roots, Shoots, Fruits & Flowers: Mystery Tree, Bamboo Control & Insecticide Damage

Small flower of mystery tree.
Photo: Jacalyn Duncan.

Mystery Tree

Jackie, a Master Gardener, shared this email with photos, “I have a tree in my yard that I would like to find out what it is. It must be an exotic because I cannot find it in any of my books. Its leaf is compound and alternate. I have also included a picture of the flower. Please help ID.”

When a reader sends in images of a plant to identify, normally the process of identification is quick. Either AHA knows or an AgCenter horticulturist will assist with ID. However, Jackie sent in her email about a month ago, and so far, she has stumped AHA. One horticulture agent incorrectly identified this tree as a boxelder. However, boxelder has opposite branches, and this tree has alternate branching. If a reader of RSFF can help find the name of this non-native tree, please contact AHA. Contact information is at the bottom of this column.

Compound leaf of the mystery tree. Photo: Jacalyn Duncan.

51_fig_3_bamboojpgA stand of bamboo. Photo: Dr. Joe Willis, LSU AgCenter.

Bamboo Invasion

Julie is fighting an invasion of bamboo, “I am writing for some help. My neighbor has bamboo along a fence line, and we are desperately trying to get it out of our flower bed. We were going to try to till up the ground to get Rhizomes and put black landscape paper down with lots of mulch. Do you think this will be successful?

Also, so you have any other tips on how to keep it out of our yard.”

AHA replied, “Your approach may be successful in the short term.

If you tilled and chopped up the rhizomes, you may have enabled bamboo baby boom. The new sprouts may eventually penetrate landscape blanket.

Let us explore some ideas to help you with longer term control. A root barrier along the fence line would provide long term protection from infestation from your neighbor's property line. Root barriers are available online from various vendors. A 24-inch-deep barrier will likely prevent new infestations.

For the current infestation of bamboo, I suggest using a product like Grass B Gon (GBG). This product selectively kills grasses, and bamboo is a grass. You will probably need multiple applications to eradicate bamboo from your yard. The key to success over bamboo is perseverance. Also, GBG is safe for broad leaf plants like flowers and vegetables.”

Also, repeated mowing of the tender bamboo sprouts will eventually control this weed for the same reason that repeated herbicide spraying will. The bamboo will run out of energy and quit. Ms. Julie can succeed if she persists and outlasts the bamboo.


Butterbean leaves with pesticide damage.
Photo: Peggy Kessler.

Pesticide Damage

Peggy saw something about her butterbeans and conveyed her concern, “Can you tell me what is attacking my butterbean leaves and what I need to do to cure it? Will it spread to other veggies?”

AHA suspected pesticide damage and asked Peggy about her pesticide use, and she shared, “Several weeks ago I sent a picture of a caterpillar to you. I ended up spraying the plant he was on with [Sevin insecticidal spray]. This plant is in the same garden area as the butterbeans.”

Even insecticides can cause damage to plants under certain situations. The University of Maryland Extension describes the conditions when plants may be harmed by pesticides, “Pesticide burn, or phytotoxicity, is caused by misuse or misapplication of chemicals on plants. Symptoms included leaf spots, blotches, scorch or tip burn. Symptoms are sometimes confused with disease, insect or mite damage or problems caused by environmental conditions.

Pesticide burn may also occur when pesticides are sprayed on stressed plants. Stressors, such as drought, disease, insect injury and frost damage, predispose plants to chemical damage. Even non-toxic sprays, such as insecticidal soaps and horticultural oils can result in pesticide burn when sprayed on injured or sensitive plants- especially when the weather is hot, humid, and overcast (poor drying conditions).

Phytotoxicity frequently occurs when pesticides are sprayed under adverse weather conditions. High temperatures and humidity, in general, will increase the possibility of injury from pesticides (insecticides and fungicides; especially soaps, oils and sulfur compounds). Cool damp weather may increase the chance of injury by copper fungicides. Phytotoxicity may also result when incompatible chemicals are applied at the same time. Damage may also occur due to wind drift onto nontarget or sensitive plants. Spray applications should be applied during calm, dry and cool conditions. Most pesticides are best applied below 85 F.

If pesticide use is warranted, be sure to apply chemicals according to label directions. Always check label directions for cautions regarding sensitive plants and combining pesticides. The plant you wish to spray should be listed on the label of the pesticide. When insects or diseases seriously damage vegetable plants, sometimes it is best to cut off the damaged parts or re-plant and learn how to prevent the problem next time.”

If you want to contact Roots, Shoots, Fruits and Flowers, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent (AHA), 337-463-7006 or Also, you can be on the “green thumbs” email list by emailing your request to the address above.

“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”

5/1/2020 3:23:19 PM
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