By Dzehner
United States 
My barrel cactus is only about 6 inches in diameter and I just transplanted it from a pot into the ground where I have planted other cactuses in a small area. The soil is mostly clay and I noticed it is getting brown spots. Is there anything that I can do to help return it to a healthier state?
23 Sep, 2013
Cacti won't grow very well in clay. They need an open porous soil.
You could dig plenty of compost and lots of grit into the soil, to make it more cactus-friendly.
23 Sep, 2013