Diseased cacti, help!

[alejarcila]

Hi all. First of all, thank you for taking the time to read this post.

Now, I'm not an expert on cacti, but we bought a few for our outdoor front yard. They are showing signs of disease but I have no idea what they are and how to save them!!! I attach a few pics. One of the cacti has some kind of brown crust that can be removed with a hard object. The others show brown areas around the place where they grow. It'll be clearer in the pics for you to understand. I'd appreciate any help please. Thank you!

[PaulF]

My first thought is not disease but overwatering. But then, what do I know not being an expert. Ours at home look similar and overwatering is what my wife says is her problem.

[imafan26]

The spots on the leaves are scale. It is easier to see them when you zoom on the picture. There are both adults and juveniles. the juveniles can be taken care of with horticultural oil. Adult scale is harder to deal with. I usually take them off by hand.
This cactus is in a pot. If the pot is anchored well, you can use a blast of water from a hose sprayer set on jet. If the pot is not stable, lie it on the ground sideways and clean the sides of the cactus one at a time. Cactus that are tall can break if they drop suddenly. You can put some stakes like rebar around the pot so it won't fall over instead. Make sure the pot is dry when you do this so the cactus won't get over watered.

Cacti are not as tough as bark so 50/50 alcohol/water with a few drops of soap. Scrub the remaining scale off with a soft brush, cotton swab or sponge. You may have to use your fingernail to get some of them off. You will have to repeat the procedure because it is really hard to get the ones near the base of the plant or small ones in the pits of the surface.

[alejarcila]

The spots on the leaves are scale. It is easier to see them when you zoom on the picture. There are both adults and juveniles. the juveniles can be taken care of with horticultural oil. Adult scale is harder to deal with. I usually take them off by hand.
This cactus is in a pot. If the pot is anchored well, you can use a blast of water from a hose sprayer set on jet. If the pot is not stable, lie it on the ground sideways and clean the sides of the cactus one at a time. Cactus that are tall can break if they drop suddenly. You can put some stakes like rebar around the pot so it won't fall over instead. Make sure the pot is dry when you do this so the cactus won't get over watered.

Cacti are not as tough as bark so 50/50 alcohol/water with a few drops of soap. Scrub the remaining scale off with a soft brush, cotton swab or sponge. You may have to use your fingernail to get some of them off. You will have to repeat the procedure because it is really hard to get the ones near the base of the plant or small ones in the pits of the surface.

Hi imafan26. Thanks for your great advise. I'll perform some of those tips on the one cactus that's got that specific infection. What about the other case where the section of the root or partition is brown? I'm afraid that looks quite difficult to repair?

[imafan26]

I have no idea what is causing the scarring. There are a lot of things that can cause scarring. From feeding damage to physical damage.