Later in Spring: Sprouting Seeds Without Watering

For the first years that I experimented with dry gardening I went
overboard and attempted to grow food as though I had no running
water at all. The greatest difficulty caused by this self-imposed
handicap was sowing small-seeded species after the season warmed up.
Sprouting what we in the seed business call "big seed"--corn, beans,
peas, squash, cucumber, and melon--is relatively easy without
irrigation because these crops are planted deeply, where soil
moisture still resides long after the surface has dried out. And
even if it is so late in the season that the surface has become very
dry, a wide, shallow ditch made with a shovel will expose moist soil
several inches down. A furrow can be cut in the bottom of that damp
"valley" and big seeds germinated with little or no watering.
Tillage breaks capillary connections until the fluffy soil
resettles. This interruption is useful for preventing moisture loss
in summer, but the same phenomenon makes the surface dry out in a
flash. In recently tilled earth, successfully sprouting small seeds
in warm weather is dicey without frequent watering.
With a bit of forethought, the water-wise gardener can easily
reestablish capillarity below sprouting seeds so that moisture held
deeper in the soil rises to replace that lost from surface layers,
reducing or eliminating the need for watering. The principle here
can be easily demonstrated. In fact, there probably isn't any
gardener who has not seen the phenomenon at work without realizing
it. Every gardener has tilled the soil, gone out the next morning,
and noticed that his or her compacted footprints were moist while
the rest of the earth was dry and fluffy. Foot pressure restored
capillarity, and during the night, fresh moisture replaced what had
evaporated.
This simple technique helps start everything except carrots and
parsnips (which must have completely loose soil to develop
correctly). All the gardener must do is intentionally compress the
soil below the seeds and then cover the seeds with a mulch of loose,
dry soil. Sprouting seeds then rest atop damp soil exactly they lie
on a damp blotter in a germination laboratory's covered petri dish.
This dampness will not disappear before the sprouting seedling has
propelled a root several inches farther down and is putting a leaf
into the sunlight.
I've used several techniques to reestablish capillarity after
tilling. There's a wise old plastic push planter in my garage that
first compacts the tilled earth with its front wheel, cuts a furrow,
drops the seed, and then with its drag chain pulls loose soil over
the furrow. I've also pulled one wheel of a garden cart or pushed a
lightly loaded wheelbarrow down the row to press down a wheel track,
sprinkled seed on that compacted furrow, and then pulled loose soil
over it.