Soils that Shed Water

Question from Barbara:

I recently read in one of your updates that you too have (or had) hydrophobic soil – the kind that water runs right off of.  How do you solve this problem? If I actively mix water into the top layer of soil by stirring it, it turns into muddy slurry.  Thanks for any help you can offer!

Answer from Pat:

The fact that sandy soils in California can become hydrophobic was first noticed and studied in Golden Gate Park in San Francisco. This problem is caused by the sand particles becoming coated with plant waxes and lining up like a phalanx with all their flat sides together. It can be a terrible problem since irrigation water can just pour off and carry some sand with it.

Topping sandy soils with horse manure in fall and allowing the rains to wash the manure into the soil can be one of the best ways to overcome this problem. Mulching the ground aids water penetration. Amending the soil with organics also helps. Every time you replant a bed of annuals or vegetables, never neglect adding organics. Additionally, wetting agents containing Yucca schidigera can help. Water basins with deep and slow watering from the hose or flooding flat ground, over-head watering, or watering with “leaky-hose-type” soaker hoses and low-volume sprinklers work better for hydrophobic soils than conventional drip systems.