In the above photo, potatoes were planted down the center of a bed. I let them sprout well before seeding the edges with peas. The peas were not planted very thickly so that they wouldn't shade out the potato plants as their vines grew. Here's another view.....
If I time it just right, the peas will be done harvesting just when the potatoes are ready to be dug up.
The way these two crops grow together is that the peas must be a vining type, in this case, Sugar Snaps. As the vines run up the trellis, the pea plants no longer rely upon the lower leaves, thus giving space below for the potato plants. By the time the vines are up the trellis, the potato plants are filling out and getting bushy. So neither crop is interfering with the other's space. I choose a potato variety that has small bushy plants.
The only tricky part is getting mulch around the potato plants. But the fencing has wide spacing, so I can apply mulch by the fistful. A bit slower than the usual dump method, but it works.
Another double planting opportunity is with the pineapple beds. Pineapples are slow growers, plus they have narrow leaves, making for plenty of space around them. It's a good spot for growing small crops, like radishes and short topped beets. It's simple to tuck in a few seeds here and there,