Dry Soil: Where Roots Won't Go

Contrary to popular belief, roots do NOT grow into dry soil. Simple as that. DryING soil - Yes. Even dryISH soil (provided it becomes progressively wetter, not drier). But DRY soil - emphatically NO. And not just dry soil - roots don't like air pockets either.

Not a very good photo. It's a pot of old coriander roots. I only noticed when I viewed it against a light background that there is an air pocket in the bottom. Look what happened to root growth as soon as they hit it - they stopped growing and presumably changed direction in search of richer pastures. This is what plants do. They send their roots out in all directions in search of ideal conditions. When they find it, they branch out prolifically; if they don't find it, they search elsewhere.

Considering the vast numbers of roots on any mature plant, I find this feat absolutely mind boggling - just the fact that the plant is in complete control of them all, as well as countless other operations conducted simultaneously. Incredible.

WATERING FOR ROOT GROWTH
In my opinion, there's no doubt about it: Constant wetting and drying of a soil is the way to more roots. But when I say 'wetting', I mean REALLY wetting, involving a good soaking - one which will sink deep into the soil or compost. Because, once drained, soil dries from the surface downwards, this induces the roots to follow the water level down.

MANY GROWERS WATER TOO EARLY
This process of drying happens naturally at this time of year (a little earlier this year in the U.K.). As soon as the surface dries, it is tempting to reach for the hose or watering can. Don't. Because, if you do, the roots will stop following the natural water table and become dependent upon the water supplied by you. And once this process occurs and the water table sinks even lower, the link is seldom re-established.

So. Don't start watering your plants until they are on the verge of wilting. You will be surprised at how long they can last out. If you can do this, it will pay dividends.