I have a couple of questions regarding my golden barrel cacti. I have five outdoor plants in a cactus garden on the northwest side of our home. I’ve noticed that the two smaller barrel cacti (one is about the size of a melon, the other the size of a grapefruit) have developed yellowish ribs and the space between each of the ribs is a light green. Are they not receiving enough sunlight? Should I place the barrels in pots and move them to an area with more direct sun? They get about 5 hours of direct sunlight this time of year.
I also water my barrel cacti about once every 10-14 days – are they receiving too much water? If it’s any help, I live in Newark, CA (about an hour south of Berkeley) and have bought some cacti from Cactus Jungle. I appreciate your feedback. Attached are two photos taken during the summer of the cacti in question.
From the pictures, the cacti look fine. In general, 5 hours is enough sun. A little yellowing could be a sign of too much water; reduce the watering to every 3 to 4 weeks except when you are getting over 90F. You can stop watering them now for the winter unless we have a particularly dry winter.