For Opuntia it doesn't matter if you get a "perched" water level below the berm substrate because Opuntia roots are shallow. They would seldom penetrate more than a foot so the 18" recommended layer will take care of the root drainage problems. I've done this for many years and have ...

Being completely off the ground would make it not drain as well. Here's a site that explains why, the principle would apply your idea the same as it does to a a flower pot - http://gardening.stackexchange.com/questions/13774/what-is-a-perched-water-table" onclick="window.open(this.href);r...

The problem with most Opuntia in your area is keeping them well drained. I see no reason at all for a "table" type of construction to keep them off the ground; sounds lethal even to Opuntia. That's the reason why I wanted to make a raised grow bed. I figured that would be the best way to ...

I'm afraid I can't help with your opuntia questions, but I'm sure more knowledgeable people will be able to give better responses if they know where you live and your local climate I live in Northern Indiana. USDA Zone 5b. Both cactus can survive my area's winters and Eastern Prickly is actually na...

I have a Tulip Prickly Pear cutting that's rooted and has been growing indoors for a month now and I am planning on getting some Eastern Prickly Pear cuttings in a week or so. I have a plan for them in the spring and would like some advice. I want to build a raised grow bed for them, with legs like ...