Gardening Without Irrigation Part 4

Organic gardeners may fertigate with combinations of fish emulsion and seaweed at the same dilution used for foliar spraying, or with compost/manure tea. Determining the correct strength to make compost tea is a matter of trial and error. I usually rely on weak Rapid-Gro mixed at half the recommended dilution. The strength of the fertilizer you need depends on how much and deeply you placed nutrition in the subsoil.

Chapter 4

Water-Wise Gardening Year-Round

Early Spring: The Easiest Unwatered Garden

West of the Cascades, most crops started in February and March require no special handling when irrigation is scarce. These include peas, early lettuce, radishes, kohlrabi, early broccoli, and so forth. However, some of these vegetables are harvested as late as June, so to reduce their need for irrigation, s.p.a.ce them wider than usual. Spring vegetables also will exhaust most of the moisture from the soil before maturing, making succession planting impossible without first irrigating heavily. Early spring plantings are best allocated one of two places in the garden plan: either in that part of the garden that will be fully irrigated all summer or in a part of a big garden that can affordably remain bare during the summer and be used in October for receiving transplants of overwintering crops. The garden plan and discussion in Chapter 6 ill.u.s.trate these ideas in detail.

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, cuc.u.mber, 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.

Handmade Footprints

Sometimes I sow large bra.s.sicas and cucurbits in clumps above a fertilized, double-dug spot. First, in a s.p.a.ce about 18 inches square, I deeply dig in complete organic fertilizer. Then with my fist I punch down a depression in the center of the fluffed-up mound. Sometimes my fist goes in so easily that I have to replace a little more soil and punch it down some more. The purpose is not to make rammed earth or cement, but only to reestablish capillarity by having firm soil under a shallow, fist-sized depression. Then a pinch of seed is sprinkled atop this depression and covered with fine earth. Even if several hot sunny days follow I get good germination without watering. This same technique works excellently on hills of squash, melon and cuc.u.mber as well, though these large-seeded species must be planted quite a bit deeper.

Summer: How to Fluid Drill Seeds

Soaking seeds before sowing is another water-wise technique, especially useful later in the season. At bedtime, place the seeds in a half-pint mason jar, cover with a square of plastic window screen held on with a strong rubber band, soak the seeds overnight, and then drain them first thing in the morning. Gently rinse the seeds with cool water two or three times daily until the root tips begin to emerge. As soon as this sign appears, the seed must be sown, because the newly emerging roots become increasingly subject to breaking off as they develop and soon form tangled ma.s.ses.

Presprouted seeds may be gently blended into some crumbly, moist soil and this mixture gently sprinkled into a furrow and covered. If the sprouts are particularly delicate or, as with carrots, you want a very uniform stand, disperse the seeds in a starch gelatin and imitate what commercial vegetable growers call fluid drilling.

Heat one pint of water to the boiling point. Dissolve in 2 to 3 tablespoons of ordinary cornstarch. Place the mixture in the refrigerator to cool. Soon the liquid will become a soupy gel.

Gently mix this cool starch gel with the sprouting seeds, making sure the seeds are uniformly blended. Pour the mixture into a 1-quart plastic zipper bag and, scissors in hand, go out to the garden. After a furrow--with capillarity restored--has been prepared, cut a small hole in one lower corner of the plastic bag.

The hole size should be under 1/4 inch in diameter. Walk quickly down the row, dribbling a mixture of gel and seeds into the furrow.

Then cover. You may have to experiment a few times with cooled gel minus seeds until you divine the proper hole size, walking speed and amount of gel needed per length of furrow. Not only will presprouted seeds come up days sooner, and not only will the root be penetrating moist soil long before the shoot emerges, but the stand of seedlings will be very uniformly s.p.a.ced and easier to thin. After fluid drilling a few times you'll realize that one needs quite a bit less seed per length of row than you previously thought.

Establishing the Fall and Winter Garden

West of the Cascades, germinating fall and winter crops in the heat of summer is always difficult. Even when the entire garden is well watered, midsummer sowings require daily attention and frequent sprinkling; however, once they have germinated, keeping little seedlings growing in an irrigated garden usually requires no more water than the rest of the garden gets. But once hot weather comes, establishing small seeds in the dry garden seems next to impossible without regular watering. Should a lucky, perfectly timed, and unusually heavy summer rainfall sprout your seeds, they still would not grow well because the next few inches of soil would at best be only slightly moist.

A related problem many backyard gardeners have with establishing the winter and overwintered garden is finding enough s.p.a.ce for both the summer and winter crops. The nursery bed solves both these problems.

Instead of trying to irrigate the entire area that will eventually be occupied by a winter or overwintered crop at maturity, the seedlings are first grown in irrigated nurseries for transplanting in autumn after the rains come back. Were I desperately short of water I'd locate my nursery where it got only morning sun and sow a week or 10 days earlier to compensate for the slower growth.

Vegetables to Start in a Nursery Bed

Variety Sowing date Transplanting date

Fall/winter lettuce mid-August early October Leeks early April July Overwintered onions early-mid August December/January Spring cabbage mid-late August November/December Spring cauliflower mid-August October/November 1st Winter scallions mid-July mid-October

Seedlings in pots and trays are hard to keep moist and require daily tending. Fortunately, growing transplants in little pots is not necessary because in autumn, when they'll be set out, humidity is high, temperatures are cool, the sun is weak, and transpiration losses are minimal, so seedling transplants will tolerate considerable root loss. My nursery is sown in rows about 8 inches apart across a raised bed and thinned gradually to prevent crowding, because crowded seedlings are hard to dig out without damage. When the prediction of a few days of cloudy weather encourages transplanting, the seedlings are lifted with a large, sharp knife.

If the fall rains are late and/or the crowded seedlings are getting leggy, a relatively small amount of irrigation will moisten the planting areas. Another light watering at transplanting time will almost certainly establish the seedlings quite successfully. And, finding room for these crops ceases to be a problem because fall transplants can be set out as a succession crop following hot weather vegetables such as squash, melons, cuc.u.mbers, tomatoes, potatoes, and beans.

Vegetables that must be heavily irrigated (These crops are not suitable for dry gardens.)

Bulb Onions (for fall harvest) Celeriac Celery Chinese cabbage Lettuce (summer and fall) Radishes (summer and fall) Scallions (for summer harvest) Spinach (summer)

Chapter 5

How to Grow It with Less Irrigation: A-Z

First, a Word About Varieties

As recently as the 1930s, most American country folk still did not have running water. With water being hand-pumped and carried in buckets, and precious, their vegetable gardens had to be grown with a minimum of irrigation. In the otherwise well-watered East, one could routinely expect several consecutive weeks every summer without rain. In some drought years a hot, rainless month or longer could go by. So vegetable varieties were bred to grow through dry spells without loss, and traditional American vegetable gardens were designed to help them do so.

I began gardening in the early 1970s, just as the raised-bed method was being popularized. The latest books and magazine articles all agreed that raising vegetables in widely separated single rows was a foolish imitation of commercial farming, that commercial vegetables were arranged that way for ease of mechanical cultivation. Closely planted raised beds requiring hand cultivation were alleged to be far more productive and far more efficient users of irrigation because water wasn't evaporating from bare soil.

I think this is more likely to be the truth: Old-fashioned gardens used low plant densities to survive inevitable spells of rainlessness. Looked at this way, widely separated vegetables in widely separated rows may be considered the more efficient users of water because they consume soil moisture that nature freely puts there. Only after, and if, these reserves are significantly depleted does the gardener have to irrigate. The end result is surprisingly more abundant than a modern gardener educated on intensive, raised-bed propaganda would think.

Finding varieties still adapted to water-wise gardening is becoming difficult. Most American vegetables are now bred for irrigation-dependent California. Like raised-bed gardeners, vegetable farmers have discovered that they can make a bigger profit by growing smaller, quick-maturing plants in high-density s.p.a.cings.

Most modern vegetables have been bred to suit this method. Many new varieties can't forage and have become smaller, more determinate, and faster to mature. Actually, the larger, more sprawling heirloom varieties of the past were not a great deal less productive overall, but only a little later to begin yielding.

Fortunately, enough of the old sorts still exist that a selective and varietally aware home gardener can make do. Since I've become water-wiser, I'm interested in finding and conserving heirlooms that once supported large numbers of healthy Americans in relative self-sufficiency. My earlier book, being a guide to what pa.s.ses for ordinary vegetable gardening these days, a.s.sumed the availability of plenty of water. The varieties I recommended in [i]Growing Vegetables West of the Cascades[i] were largely modern ones, and the seed companies I praised most highly focused on top-quality commercial varieties. But, looking at gardening through the filter of limited irrigation, other, less modern varieties are often far better adapted and other seed companies sometimes more likely sources.

Seed Company Directory*

Abundant Life See Foundation: P.O. Box 772, Port Townsend, WA 98368 _(ABL)_

Johnny's Selected Seeds: Foss Hill Road, Albion, Maine 04910 _(JSS)_

Peace Seeds: 2345 SE Thompson Street, Corvallis, OR 97333 _(PEA)_

Ronninger's Seed Potatoes: P.O. Box 1838, Orting, WA 98360 _(RSP)_