Q. I applied Bonide Tree and Shrub insect control for
borers and miners about six weeks ago. Now my plants are growing weird and
possibly dying. Once I saw this problem, I sprayed for diseases and then today
for insects. What is going on?
borers and miners about six weeks ago. Now my plants are growing weird and
possibly dying. Once I saw this problem, I sprayed for diseases and then today
for insects. What is going on?
Picture not available
A. The damage to the plant was probably weed killer (herbicide) damage
judging from the distorted leaves and dieback. There is not much to do at this
point except spray the foliage with water, irrigate, and make sure the plants
were fertilized in the spring, so they are in their best health to recover as
quickly as possible. Then wait and see what happens. There is no magic cure at
this point except being patient for three or four weeks.
judging from the distorted leaves and dieback. There is not much to do at this
point except spray the foliage with water, irrigate, and make sure the plants
were fertilized in the spring, so they are in their best health to recover as
quickly as possible. Then wait and see what happens. There is no magic cure at
this point except being patient for three or four weeks.
Let’s
cover some reasons why this might happen so it might be prevented in the
future. The damage could have originated from you or your neighbors. This type
of damage is a common occurrence during the spring and the fall months because
these are the most effective times to apply weed killers.
cover some reasons why this might happen so it might be prevented in the
future. The damage could have originated from you or your neighbors. This type
of damage is a common occurrence during the spring and the fall months because
these are the most effective times to apply weed killers.
Sprayer Not Rinsed
First,
never use a sprayer or spray bottle that contained weed killers to spray
insects or diseases. You should have two separate sprayers or bottles; one clearly
marked and used for “Weed Killers”. Weed killers are extremely difficult to
clean from a sprayer or spray bottle once it’s been used for that purpose. If
there is some weed killer residue that remains after washing, then voilà,
you just damaged plants that you sprayed for controlling insects and diseases!
never use a sprayer or spray bottle that contained weed killers to spray
insects or diseases. You should have two separate sprayers or bottles; one clearly
marked and used for “Weed Killers”. Weed killers are extremely difficult to
clean from a sprayer or spray bottle once it’s been used for that purpose. If
there is some weed killer residue that remains after washing, then voilà,
you just damaged plants that you sprayed for controlling insects and diseases!
Spray Drift
Secondly,
you or your neighbors should never spray weed killers when there is wind. If
you must use a weed killer, look at the tallest trees in the neighborhood and
see if their leaves are moving. If they are, do not spray weed killers. The
best time to spray weed killers is early in the morning before the wind has
kicked up and it starts to get warm.
you or your neighbors should never spray weed killers when there is wind. If
you must use a weed killer, look at the tallest trees in the neighborhood and
see if their leaves are moving. If they are, do not spray weed killers. The
best time to spray weed killers is early in the morning before the wind has
kicked up and it starts to get warm.
Heat
The
word “warm” takes me to the third rule; never spray a warm surface or when air
temperatures are warm or hot. Landscape rock mulch heats up quickly as soon as
the sun comes up. On a warm day, these surfaces reach 150°F or more by 9 AM on
a sunny spring day. When weed killers are sprayed on hot surfaces, they
volatilize and move to the neighbor’s yard with the gentlest air movement and
can cause plant damage.