Then shallowly hoe the soil every day or two to encourage the
surface inches to dry out and form a dust mulch. You water-wise
person--you're already dry gardening--now start fertigating.

How long available soil water will sustain a crop is determined by
how many plants are drawing on the reserve, how extensively their
root systems develop, and how many leaves are transpiring the
moisture. If there are no plants, most of the water will stay unused
in the barren soil through the entire growing season. If a crop
canopy is established midway through the growing season, the rate of
water loss will approximate that listed in the table in Chapter 1
"Estimated Irrigation Requirement." If by very close planting the
crop canopy is established as early as possible and maintained by
successive interplantings, as is recommended by most advocates of
raised-bed gardening, water losses will greatly exceed this rate.

Many vegetable species become mildly stressed when soil moisture has
dropped about half the way from capacity to the wilting point. On
very closely planted beds a crop can get in serious trouble without
irrigation in a matter of days. But if that same crop were planted
less densely, it might grow a few weeks without irrigation. And if
that crop were planted even farther apart so that no crop canopy
ever developed and a considerable amount of bare, dry earth were
showing, this apparent waste of growing space would result in an
even slower rate of soil moisture depletion. On deep, open soil the
crop might yield a respectable amount without needing any irrigation
at all.

West of the Cascades we expect a rainless summer; the surprise comes
that rare rainy year when the soil stays moist and we gather