Monday, June 8, 2020

Tree Cattle and Lichens

Horticulture Hotline 06/08/2020
By Bill Lamson-Scribner

What a different year – and the Horticulture Hotline has suffered! For over 30 years I wrote this column every Monday morning without fail. I believe at least twice this spring Monday has come and gone without me writing the Horticulture Hotline. I was talking to a friend last week about grub damage, and in my mind, I was picturing that it was April and they should be near the surface feeding – causing damage. He reminded me that it was June. I quickly corrected myself and said the grubs have been emerging as beetles. These beetles (June beetles, Japanese beetles) have been shredding many of your ornamental plants (roses, crepe myrtles…). I completely lost the month of May! Maybe selling masks (starving my brain of oxygen), hand sanitizer (taking a sip to be sure alcohol content is remaining high or dermal exposure) and gloves has affected me!

Tree cattle or bark lice (louse) are out in big numbers. They do not eat leaves. If you try to scare them away with a branch, they scattered, usually just by running to the other side of the tree, and then they regrouped on the tree.  Tree cattle look scary, but they are good guys.  The tree cattle clean the tree by eating dead organic matter and lichens (algae and moss combination) out of the bark crevices of the tree.  Even though crepe myrtles have smooth bark, there are plenty of places for the tree cattle to find food.  They are the house cleaners of the trees! Maples are another favorite tree of the tree cattle.

Tree cattle produce that stocking like webbing that looks like something out of a horror movie in the late summer and fall.  The webbing is tight against the bark of the tree just like a stocking.  It is found on limbs as well as trunks of trees.  The tree cattle use this webbing as protection from predators and weather. 

Tree cattle do not harm a tree. They do not eat leaves, just dead organic matter.  If they are really bugging you, you could spray them with a blast of water.  I would let them clean the bark of the tree, so you do not have excessive organic debris buildup.

If you have a lot of lichens, you may want to check the general health of the tree. Lichens produce their own food like plants. If you have a healthy thick canopy of foliage from the tree, lichens will not grow because they cannot get the sunlight they need to survive. A soil test and the appropriate fertilizer should help with this situation unless the tree has other cultural issues (compacted soils, wet soils, dry soil, planted incorrectly or in the wrong place …).  

Mosquitoes, fleas, Palmetto bugs (big roaches), flies, stinging insects are out!

Always read, understand and follow product label. The product label is a Federal Law.

Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA (The Big Talker). Saturday's show is replayed Sunday from 11:00 - Noon.