The Secret to Arizona Gardening: High Berms

Berms and deep watering.

I just raised up and strengthened my berms this week, to help the plants cope with the extra heat. Small berms are ok for the mild spring months, when just a light soaking will keep the soil moist. But for the 90+ degree days of late spring/early summer, a deeper soaking is necessary.

With only shallow watering, the plant roots only grow shallowly, because the water never really penetrates the soil more than an inch or so. With deep watering, the soil will get moist deep down, and the roots will follow. Those deep roots will keep your plants much healthier when the real hot days hit.

So in order to get those deep waterings, you have to let the water pile up and sit for awhile, and slowly set down in where you want it to go. I recommend berm edges at least 4 inches high all around your growing area. That way you can flood your growing area with 2-3 inches of water at a time, and the water stays right where you want it.

Just be careful to watch that the water doesn't rise above the berm edge. Once the water flows over the edge, it will quickly rip a huge hole in your berm wall and all the water will escape.