Water-Wise Gardening Science

Plants Are Water





Like all other carbon-based life forms on earth, plants conduct
their chemical processes in a water solution. Every substance that
plants transport is dissolved in water. When insoluble starches and
oils are required for plant energy, enzymes change them back into
water-soluble sugars for movement to other locations. Even cellulose
and lignin, insoluble structural materials that plants cannot
convert back into soluble materials, are made from molecules that
once were in solution.

Water is so essential that when a plant can no longer absorb as much
water as it is losing, it wilts in self-defense. The drooping leaves
transpire (evaporate) less moisture because the sun glances off
them. Some weeds can wilt temporarily and resume vigorous growth as
soon as their water balance is restored. But most vegetable species
aren't as tough-moisture stressed vegetables may survive, but once
stressed, the quality of their yield usually drops markedly.

Yet in deep, open soil west of the Cascades, most vegetable species
may be grown quite successfully with very little or no supplementary
irrigation and without mulching, because they're capable of being
supplied entirely by water already stored in the soil.