pjkfarm

Not quite the forum, though they like some things bananas like or better say hate the same things - WET FEET. We grow in Virginia - hot/cold/humid. Have over 100 different cacti/yucca/agave. 6" is too low - 1 foot minimum. DRAINAGE is all that really matters - we have them growing in clay (wild), compost piles (prunings and throw aways). ONLY important thing is drainage. As water will wick up even putting a piece of plastic under your bed could work if the area your raised bed is on is very flat or otherwise soggy. If the area is well drained, not such an issue. but for sure try more than six inches :-) BTW, do not fertilise after june or so, and we never fertilise cacti unless in pots and then very little.