scale on bay plant

Asked February 25, 2015, 8:40 AM EST

I have a 4 year old bay plant on which I discovered scale last Fall.
Now that the warm weather is around the corner, I need to begin some control
and eradication measures. Since is is a culinary plant I want to avoid using a systemic insecticide. I can use soap of course but not so effective with scale.
What do you suggest and when is the right timing?

Washington County Oregon disease issues scale horticulture

4 Responses

I’m guessing that your bay tree is indoors, correct? If so, you need to know that bay tree is hardy in our region and will survive when planted in the garden. If you want to keep it in a container, you can also keep it outdoors but you will need to protect it whenever 32F or below is predicted. (Potted plants are more than likely to be damaged by cold than the same kind planted in the ground.) (See https://www.rhs.org.uk/advice/profile?PID=251 and http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/grecian.html) Depending upon the vigor of your bay tree, you might want to consider obtaining a healthy replacement and maintain it outdoors.

If you are determined to attempt to clear the scale, be aware that insecticidal soap can be effective if you apply it when the crawlers (new hatchlings) are present. Unfortunately, that can occur any time of year on an indoor plant. To help time the insecticidal soap spray, encircle a scale-infested branch with two bands of double sticky tape, one band above the scale, one below. Check the tape now and then to determine when the newly hatched scale are on the move, and then spray the tree thoroughly. (Do so outdoors, in the shade.) Good luck.





Hello Jean,

Thank you for your response and advice.
I should have mentioned that the bay plant is outside in my garden and is about 3 feet tall. I recently pruned it in an attempt to reduce the amount of coverage needed in the spraying process. How big are the crawlers and are they easy to see?
shall I plan on spraying every week to 10 days?
Thanks,
Paulette

tha


Paulette,

Scale on an outdoor bay tree suggests that the tree is stressed. The causes can include the where it’s planted in the garden as well as day-to-day care. An image of the tree and its surroundings might be helpful in revealing its general health.

Visit this site to determine if what you see on your plant is soft brown scale. The large oval insect (towards the right) is the adult at just 2.5 to 4 mm long. The smallest, light-colored oval insects are crawlers. http://content.ces.ncsu.edu/brown-soft-scale-insect-coccus-hesperidum/ If your scale is different, please send an image.

You should plant to spray the plant is when you see crawlers. Determine when that it by using 2 bands of double-sided sticky tape, one placed above some of the scale, the other below.

I look forward to receiving your images; one of the tree, the other of the scale



Uh oh. I see several typos in the next to last paragraph. It should read as follows:

You should plan to spray the plant when you see crawlers. Determine when that is by using 2 bands of double-sided sticky tape, one placed above some of the scale, the other below. Generally that’s during June and again in August.


Good luck.