Q.My euonymus plants are dying. These are all
plants that have been in the ground 8-10 years. Now, they are getting a white
spot on their leaves and shortly afterwards the plants die. The plants in my
backyard did this last year, and now plants in the front have the same
symptoms. Some people said they needed more water. That didn’t do anything for
the white spot. I tried cutting off the spotted leaves. That might help, but I
am not sure. Is there anything I can spray or dust the plants with to stop the
fungus?
plants that have been in the ground 8-10 years. Now, they are getting a white
spot on their leaves and shortly afterwards the plants die. The plants in my
backyard did this last year, and now plants in the front have the same
symptoms. Some people said they needed more water. That didn’t do anything for
the white spot. I tried cutting off the spotted leaves. That might help, but I
am not sure. Is there anything I can spray or dust the plants with to stop the
fungus?
 |
| Powdery mildew and leaf death. Powdery mildew is deeper inside the canopy were it is shady. |
A. I am not sure what you mean by a white spot, whether this
white spot can be rubbed off or whether it is permanent. These plants do get
powdery mildew which looks like leaves have been dusted with white flour in
some locations.This disease occurs on plants in shady locations.
white spot can be rubbed off or whether it is permanent. These plants do get
powdery mildew which looks like leaves have been dusted with white flour in
some locations.This disease occurs on plants in shady locations.
If it is powdery mildew it usually
means they are not getting enough sun or the canopy of the plant is not open
enough for air movement. Powdery mildew, unlike other fungal diseases, requires
very little humidity to become a problem. It is spread by splashing water from
overhead irrigation hitting the leaves and splashing on others carrying the
disease to these leaves and so it spreads.
means they are not getting enough sun or the canopy of the plant is not open
enough for air movement. Powdery mildew, unlike other fungal diseases, requires
very little humidity to become a problem. It is spread by splashing water from
overhead irrigation hitting the leaves and splashing on others carrying the
disease to these leaves and so it spreads.
You can buy a dust or spray to
control powdery mildew but that just circumvents the problem and it will come
back. The long term way to control it is to get more sun on the plants (move or
prune them to open the canopy up), improve their health with fertilizers and
appropriate watering. If the plant is under watered the canopy will be very
open and I doubt you would have powdery mildew unless it is in shade or partial
shade.
control powdery mildew but that just circumvents the problem and it will come
back. The long term way to control it is to get more sun on the plants (move or
prune them to open the canopy up), improve their health with fertilizers and
appropriate watering. If the plant is under watered the canopy will be very
open and I doubt you would have powdery mildew unless it is in shade or partial
shade.
A white spot can also mean
scorching of the leaves due to direct intense sunlight. This type of damage
cannot be rubbed off with your fingers. It is permanent damage to the leaf. If
this is the case then the plant may be in the wrong spot (intense sunlight or
lots of reflected heat and/or light from windows and a west or southwest
exposure and planted in rock.
scorching of the leaves due to direct intense sunlight. This type of damage
cannot be rubbed off with your fingers. It is permanent damage to the leaf. If
this is the case then the plant may be in the wrong spot (intense sunlight or
lots of reflected heat and/or light from windows and a west or southwest
exposure and planted in rock.
If this is the case then you need to move it
away from this intense location into one that is more cooling with less intense
sunlight. This is not a desert plant and cannot handle this kind of exposure.
It does not like rock mulch very much so put it in organic mulch on the soil
surface.
away from this intense location into one that is more cooling with less intense
sunlight. This is not a desert plant and cannot handle this kind of exposure.
It does not like rock mulch very much so put it in organic mulch on the soil
surface.
If it has only one drip emitter,
put two or three depending on its size. If you are watering every day then
water deeply every other day or every third day now. Make sure you fertilize
this plant in the spring with a good tree shrub fertilizer.
put two or three depending on its size. If you are watering every day then
water deeply every other day or every third day now. Make sure you fertilize
this plant in the spring with a good tree shrub fertilizer.
If you want to move this plant, you
can move it to a new location in October, moving as much of the soil with it as
possible, and mulch it. Predig the hole and move it and plant it in less than
30 seconds once the roots are exposed.
can move it to a new location in October, moving as much of the soil with it as
possible, and mulch it. Predig the hole and move it and plant it in less than
30 seconds once the roots are exposed.
Euonymus does much better with a wood surface mulch.Neem oil is a pretty good organic control for powdery mildew.