Many experts tell us to amend our soil before planting. That may work in many places, but the rule of thumb in desert gardening is if it ain't broke, don't fix it.
Watching a program the other day on one of those "garden channels," an expert was describing how to amend the soil.
Unfortunately, what works for most of the world doesn't work for deserts. Why? Because most soils are slightly to highly acidic, and it's relatively easy to alter the pH some to make the soil habitable to plants that thrive.
Not so in the desert. Desert soils are mostly highly alkaline, so using the "usual" types of soil amendments are completely useless.
In fact, many plants that thrive in desert environments are tough, hardy plants that are accustomed to doing well in poor soil.
Let's take trees and shrubs for instance. You purchase a flowering locust at your local nursery. You dig a hole for it. According to many, you would then take the backfill and amend it with good compost, high-grade topsoil, and other nutrients. That's a big no-no in desert gardens.
The best way to treat plants that are native to the desert is to dig a hole (at least twice the diameter of the root ball), take the tree out of its container and put it in the hole and backfill. You may want your hole to be a little deeper than the depth of the container, so you can have a well around the tree to water it and to contain mulch.
Then water regularly for several months (once a week is fine), then return to the recommended watering routine.
If you amend the soil, the tree's roots will take the path of least resistance, and go round and round in the hole, feeding off the amended soil and not developing roots past the hole.
The tree will then become root-bound and may die. It will certainly be more susceptible to drying out, disease, cold and heat.
