Brown Spots On Cactus - Knowledgebase Question

Name: Susan Ballard
Nashville, TN
Avatar for flgator28
Question by flgator28
November 21, 1999
I have a cactus that has brown spots all over it. It looks like rust. It does not penetrate into the cactus and is just on the surface. It also seems to be draining the color out of the cactus. Can you tell what it is and how I can cure it. Thanks!

Answer from NGA
November 21, 1999
There are a few common cactus pests that fit the description you've given, so you'll need to put on your detective cap, take a magnifying glass, and get up close to your cactus. If the affected areas are bronzed and mottled, the likely problem is spider mite damage. If the patches are corky, it could be due to physical injury, insect damage or sudden chilling. Brown soft patches indicate a rot disease, and hard brown spots can be scale insects.

Based upon your observance that the color is draining out, I'd suspect scale insects. These common pests attach themselves to stems (or in this case pads) and suck the juices out of the tissues. The result is a pale-looking area where the scales are feeding. Try dislodging the spots. If they pop off, they're probably scales. If the spots won't peel off, and affect the tissues below the skin of the cactus, they may indicate disease.

After you've done a little detective work, let us know the results (via this Q & A platform) and we'll provide some treatment options.

Lakeville MN 55044
Avatar for MarionHawksford
A comment from MarionHawksford
September 26, 2017
I was able to scrape off the brown spots. What do I do next. Is. This rot on my plant?

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:

( No account? Join now! )

Today's site banner is by Murky and is called "Million Bells and Lobelia"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.