OK, one of our readers wanted us to dive deep into hydrophobic soils in the nursery setting this season. To get everyone on the same page, hydrophobia is a soil that tends to repel water instead of absorb it.
Perhaps the most obvious thing would be if a soil throws you a lot of troubles, it may be best to use a different brand. Severe hydrophobia is usually a sign of the soil’s composition. Sometimes it’s what’s in the soil, but it can also be the texture or even chemistry of the soil.
But, that’s a cop out. So let’s look at how water interacts with soil. It happens in one of three ways. Immediate absorption, transferred absorption and zero absorption, otherwise known as hydrophobia. Immediate absorption is ideal, of course.
Very dry soils tend to absorb water much less quickly than soils with some moisture in them. So, the speed at which you introduce water makes a huge difference. For soils prone to hydrophobia, slower and lesser initial applications of water will sort of “prime” the soil to absorb more water later. In addition, surface area matters. A spray pattern creates more contact surface area between water and soil, compared to something like a watering can.
A lot of you know our passion for subirrigation here. The technique heavily relies on transferred absorption. Essentially, water saturated soil placed in direct contact with dry soil will slowly transfer excess moisture into the dry soil. Bottom watering is a similar technique that gets to the same endpoint.
As a last ditch effort, amending the soil might also help. Ingredients like coco coir or peat moss are great at absorbing moisture. If you have a less than ideal soil, you can make it more ideal by adding ingredients that achieve the desired goal. This will encourage that transferred absorption to occur.
So, if you’re fighting difficult water-repelling soils, that’s a few of our thoughts!
