Hi there - over the past three months my cacti have started to lose their green get red at the tops and tips. I water them lightly every two weeks, and they are at a window facing northwest - they get full afternoon sun.
Are they sunburned? Underwatered/overwatered? In need of fertilizer? Or is this normal?
If anyone has any advice, I would appreciate it!
Several things can cause red/pink/purple foliage, with genetics being one of them. IOW, there's a possibility it could be the plant's normal habit. Cool temps, a P deficiency, or anything that slows growth w/o impeding the photosynthetic process can cause a build-up of the red pigment, anthocyanin.
It's not sunburn, which usually causes a silver or gray appearance before the foliage turns brown, or black - then brown.
Al
Even though you only water every 2 weeks, do the plants get left with water sitting in the bottom of the pots saucers etc, there appears to be a lot of dead either roots or plant material left on top of the pot / soil but, its hard to see from the pic.
Remove this and it will allow air to flow around the soil and the plant, If I were you I would re-pot the plant before the growing season really takes off and use shop bought compost specially for cacti, don't use a pot thats too large as you are better potting bigger again next year at the same time of year.
Hope this helps you out, WeeNel.
