I am designing a permaculture vegetable garden and I have local prickly pear cactus that the Cherokee has cultivated here in Kentucky for a long time. It is very hardy and survived a -10 winter in a pot. So I want to incorporate it in but I wanted to find out some cool companion plants for it. Also this variety thrives even in heavy clay soil. Any thoughts?
Prickly pear doesn't cast a great deal of shade and for this reason I like to pair it with groundcovers that will intercept the remaining light. Here's a list of different plants I've used, with a quick explanation for each.
Purslane (Portulaca oleraceae) - A low growing annual vegetable, which also uses CAM photosynthesis similar to the prickly pear. I'll pair these two xerophytes together if the growing conditions are particularly arid.
Strawberry (Fragaria species) - A low growing fruiting groundcover, I'll use this pairing if the conditions are humid. The strawberries will use the extra water that the prickly doesn't need, and the berries will produce well with the extra light.
Tree onions (Allium x proliferum) - Begins producing in fairly cold weather while the prickly pear is dormant. Likewise, becomes dormant itself during the hot weather when the prickly is producing. Able to store moisture in its bulb, enabling it to survive in the dry conditions that the prickly will like.
Cilantro (Coriandrum sativum) - Low growing culinary herb. This pairing is just a matter of convenience, as I use the two together in cooking.
As far as the pricklies themselves, I use these species.
Erect prickly pear (Opuntia stricta) - An upright pear that is tolerant of cold and humidity. Produces a decent fruit, but the very tough skin and internal fibers of the pads make it inedible as a vegetable. Only the new pads are soft enough to be eaten. Tolerates drier conditions than O. humifusa, but grows slower as a consequence.
Eastern prickly pear (Opuntia humifusa) - A low growing/prostrate pear, very tolerant of cold and humidity. Fruits are decent tasting but contain many large rock hard seeds, rendering them impractical for fresh eating. Excels as a vegetable variety because it lacks the stronger internal fibers of upright pricklies. Pads remain soft enough to be eaten for quite some time, but eventually the skin will become too tough to chew.