sick tree treatment
First a little background. Texas A&M and theTexas Forest Service recommend a program of trenching
to separate the roots of sick trees from those of healthy trees, cutting down sick and nearby healthy
trees, and injecting a toxic chemical fungicide called Alamo directly into the root flares of the trees.
I don’t recommend this program because it does nothing to address the cause of the disease and it never
works to cure infested trees.
Trees succumb to insect pests and diseases because they are in stress and sick. Mother Nature then
sends in the clean up crews. Insects and pathogens are just doing their job - trying to take out the
unfit plants. Most plant sickness is environmental - too much water, not enough water, too much fertilizer,
wrong kind of fertilizer, toxic chemical pesticides, compaction of soil, grade changes, ill-adapted plant
varieties and/or over planting single plant species and creating monocultures, as was done with American
elms in the Northwest and the red oak/live oak communities in certain parts of Texas.
My plan is simple. Keep trees in a healthy condition so their immune systems can resist insect pests
and diseases. It has been noticed by many farmers and ranchers that oak wilt doesn’t bother some trees -
especially those that are mulched and those where the natural habitat under trees has been maintained.
The Sick Tree Treatment is not just good for oak wilt, but for any other tree disease as well. Here is how it works.
step 1: Remove Excess soil from above the root ball
A very high percentage of trees are too deep in their containers and also have been planted too low or have
had fill soil or eroded soil added on top of the root flares. Soil on top of the root flare reduces oxygen
availability and leads to circling and girdling roots. Soil, or even heavy mulch, on trunks keeps the bark
constantly moist which can rot or girdle trees. Excess soil and circling and girdling roots should be removed
before planting. Removing soil from the root flares of already planted trees should be done professionally
with a tool called the Air Spade. Homeowners can do the work by hand with a stiff broom or gentle water
and a shop vac if done very carefully. Vines and ground covers should also be kept off tree trunks.
Trees with Buried Root Flares.
Trees with Properly Exposed Root Flares
Step 2: Aerate the Root Zone Heavily
Don’t rip, till or plow the soil. That destroys all the feeder roots. Punch holes (with turning forks,
core aerators or agriculture devices such as the Air-Way) heavily throughout the root zone. Start between
the drip line and the trunk and go far out beyond the drip line, 6-8" deep holes are ideal, but any depth
is beneficial. An alternative is to spray the root zone with a living organism product or bio-stimulant
such as an aerated compost tea.
Step 3: Apply Organic Amendments
Apply greensand at about 40-80 lbs. / 1,000 sq. ft., lava sand at about 80-120 lbs. / 1,000 sq. ft.,
horticultural cornmeal at about 20-30 lbs. / 1,000 sq. ft. and dry molasses at about 10-20 lbs. / 1,000 sq. ft.
Cornmeal is a natural disease fighter and molasses is a carbohydrate source to feed the microbes in the soil.
Expanded shale applied at 1/2 " is also very helpful if the budget allows this step. Apply a 1" layer of compost
followed by a 3" layer of shredded native tree trimmings; however, do not pile mulch up on the root flare or the
trunk. Smaller amounts of these materials can be used where budget restrictions exist.
Step 4: Spray Trees and Soil
Spray the ground, trunks, limbs, twigs and foliage of trees with compost tea or the entire Garrett Juice mixture.
Do this monthly or more often if possible. For large-scale farms and ranches, a one-time spraying is beneficial
if the budget doesn’t allow ongoing sprays. Adding garlic oil tea or cornmeal juice to the spray is also beneficial
for disease control while the tree is in trouble. Cornmeal Juice is a natural fungal control that is made by soaking
horticultural or whole ground cornmeal in water at 1 cup per 5 gallons of water. Screen out the solids and spray
without further dilution. Cornmeal Juice can be mixed with compost tea, Garrett Juice or any other natural foliar
feeding spray. It can also be used as a soil drench for the control of soil borne diseases. Dry granulated garlic
can also be used on the soil in the root zone at about 1-2 lbs. per 1000 sq. ft. for additional disease control.
Adding PLANT WASH to the spray is also beneficial.
Step 5: Stop Using High Nitrogen Fertilizers and Toxic Chemical Pesticides
Toxic chemical pesticides kill beneficial nematodes, other helpful microbes and good insects, and also control
the pest insects poorly. Synthetic fertilizers are unbalanced, harsh, high in salt, often contaminated and
destructive to the chemistry, the structure and the life in the soil. They also feed plants poorly.