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 masses.
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 spaced 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.

Handmade Footprints

Sometimes I sow large brassicas and cucurbits in clumps above a
fertilized, double-dug spot. First, in a space 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 cucumber as well, though these
large-seeded species must be planted quite a bit deeper.

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.

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, space 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 illustrate these
ideas in detail.

Increasing Soil Fertility Saves Water

Does crop growth equal water use? Most people would say this statement seems likely to be true.

Actually, faster-growing crops use much less soil moisture than slower-growing ones. As early as 1882 it was determined that less water is required to produce a pound of plant material when soil is fertilized than when it is not fertilized. One experiment required 1,100 pounds of water to grow 1 pound of dry matter on infertile soil, but only 575 pounds of water to produce a pound of dry matter on rich land. Perhaps the single most important thing a water-wise gardener can do is to increase the fertility of the soil, especially the subsoil.

"Poor plant nutrition increases the water cost of every pound of drymatter produced."

Using foliar fertilizers requires a little caution and forethought. Spinach, beet, and chard leaves seem particularly sensitive to foliars (and even to organic insecticides) and may be damaged by even half-strength applications. And the cabbage family coats its leaf surfaces with a waxy, moisture-retentive sealant that makes sprays bead up and run off rather than stick and be absorbed. Mixing foliar feed solutions with a little spreader/sticker, Safer's Soap, or, if bugs are also a problem, with a liquid organic insecticide like Red Arrow (a pyrethrum-rotenone mix), eliminates surface tension and allows the fertilizer to have an effect on brassicas.

Sadly, in terms of nutrient balance, the poorest foliar sprays are organic. That's because it is nearly impossible to get significant quantities of phosphorus or calcium into solution using any combination of fish emulsion and seaweed or liquid kelp. The most useful possible organic foliar is 1/2 to 1 tablespoon each of fish emulsion and liquid seaweed concentrate per gallon of water.

Foliar spraying and fertigation are two occasions when I am comfortable supplementing my organic fertilizers with water-soluble chemical fertilizers. The best and most expensive brand is Rapid-Gro. Less costly concoctions such as Peters 20-20-20 or the other "Grows," don't provide as complete trace mineral support or use as many sources of nutrition. One thing fertilizer makers find expensive to accomplish is concocting a mixture of soluble nutrients that also contains calcium, a vital plant food. If you dissolve calcium nitrate into a solution containing other soluble plant nutrients, many of them will precipitate out because few calcium compounds are soluble. Even Rapid-Gro doesn't attempt to supply calcium. Recently I've discovered better-quality hydroponic nutrient solutions that do use chemicals that provide soluble calcium. These also make excellent foliar sprays. Brands of hydroponic nutrient solutions seem to appear and vanish rapidly. I've had great luck with Dyna-Gro 7-9-5. All these chemicals are mixed at about 1 tablespoon per gallon.

Vegetables That:
Like foliars
Asparagus
Carrots
Melons
Squash
Beans
Cauliflower
Peas
Tomatoes
Broccoli
Brussels sprouts
Cucumbers
Cabbage
Eggplant
Radishes
Kale
Rutabagas
Potatoes

Don't like foliars
Beets
Leeks
Onions
Spinach
Chard
Lettuce
Peppers

Like fertigation
Brussels sprouts
Kale
Savoy cabbage
Cucumbers
Melons
Squash
Eggplant
Peppers
Tomatoes

Fertigation every two to four weeks is the best technique for maximizing yield while minimizing water use. I usually make my first fertigation late in June and continue periodically through early September. I use six or seven plastic 5-gallon "drip system" buckets, set one by each plant, and fill them all with a hose each time I work in the garden. Doing 12 or 14 plants each time I'm in the garden, it takes no special effort to rotate through the mall more or less every three weeks.

To make a drip bucket, drill a 3/16-inch hole through the side of a 4-to-6-gallon plastic bucket about 1/4-inch up from the bottom, or in the bottom at the edge. The empty bucket is placed so that the fertilized water drains out close to the stem of a plant. It is then filled with liquid fertilizer solution. It takes 5 to 10 minutes for 5 gallons to pass through a small opening, and because of the slow flow rate, water penetrates deeply into the subsoil without wetting much of the surface. Each fertigation makes the plant grow very rapidly for two to three weeks, more I suspect as a result of improved nutrition than from added moisture.

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.

Fertilizing, Fertigating and Foliar Spraying

In our heavily leached region almost no soil is naturally rich, while fertilizers, manures, and potent composts mainly improve the topsoil. But the water-wise gardener must get nutrition down deep, where the soil stays damp through the summer.

If plants with enough remaining elbow room stop growing in summer and begin to appear gnarly, it is just as likely due to lack of nutrition as lack of water. Several things can be done to limit or prevent midsummer stunting. First, before sowing or transplanting large species like tomato, squash or big brassicas, dig out a small pit about 12 inches deep and below that blend in a handful or two of organic fertilizer. Then fill the hole back in. This double-digging process places concentrated fertility mixed 18 to 24 inches below the seeds or seedlings.

Foliar feeding is another water-wise technique that keeps plants growing through the summer. Soluble nutrients sprayed on plant leaves are rapidly taken into the vascular system. Unfortunately, dilute nutrient solutions that won't burn leaves only provoke a strong growth response for 3 to 5 days. Optimally, foliar nutrition must be applied weekly or even more frequently. To efficiently spray a garden larger than a few hundred square feet, I suggest buying an industrial-grade, 3-gallon backpack sprayer with a side-handle pump. The store that sells it (probably a farm supply store) will also support you with a complete assortment of inexpensive nozzles that can vary the rate of emission and the spray pattern. High-quality equipment like this outlasts many, many cheaper and smaller sprayers designed for the consumer market, and replacement parts are also available. Keep in mind that consumer merchandise is designed to be consumed; stuff made for farming is built to last.

Windbreaks

Plants transpire more moisture when the sun shines, when temperatures are high, and when the wind blows; it is just like drying laundry. Windbreaks also help the garden grow in winter by increasing temperature.

Mulching

Gardening under a permanent thick mulch of crude organic matter is recommended by Ruth Stout and her disciples as a surefire way to drought-proof gardens while eliminating virtually any need for tillage, weeding, and fertilizing. I have attempted the method in both Southern California and western Oregon--with disastrous results in both locations. What follows in this section is addressed to gardeners who have already read glowing reports about mulching.

Permanent mulching with vegetation actually does not reduce summertime moisture loss any better than mulching with dry soil, sometimes called "dust mulching." True, while the surface layer stays moist, water will steadily be wicked up by capillarity and be evaporated from the soil's surface. If frequent light sprinkling keeps the surface perpetually moist, subsoil moisture loss can occur all summer, so unmulched soil could eventually become desiccated many feet deep. However, capillary movement only happens when soil is damp. Once even a thin layer of soil has become quite dry it almost completely prevents any further movement. West of theCascades, this happens all by itself in late spring. One hot, sunny day follows another, and soon the earth's surface seems parched.

Unfortunately, by the time a dusty layer forms, quite a bit of soil water may have risen from the depths and been lost. The gardener can significantly reduce spring moisture loss by frequently hoeing weeds until the top inch or two of earth is dry and powdery. This effort will probably be necessary in any case, because weeds will germinate prolifically until the surface layer is sufficiently desiccated. On the off chance it should rain hard during summer, it is very wise to again hoe a few times to rapidly restore the dust mulch. If hand cultivation seems very hard work, I suggest you learn to sharpen your hoe.

A mulch of dry hay, grass clippings, leaves, and the like will also retard rapid surface evaporation. Gardeners think mulching prevents moisture loss better than bare earth because under mulch the soil stays damp right to the surface. However, dig down 4 to 6 inches under a dust mulch and the earth is just as damp as under hay. And, soil moisture studies have proved that overall moisture loss using vegetation mulch slightly exceeds loss under a dust mulch.

West of the Cascades, the question of which method is superior is a bit complex, with pros and cons on both sides. Without a long winter freeze to set populations back, permanent thick mulch quickly breeds so many slugs, earwhigs, and sowbugs that it cannot be maintained for more than one year before vegetable gardening becomes very difficult. Laying down a fairly thin mulch in June after the soil has warmed up well, raking up what remains of the mulch early the next spring, and composting it prevents destructive insect population levels from developing while simultaneously reducing surface compaction by winter rains and beneficially enhancing the survival and multiplication of earthworms. But a thin mulch also enhances the summer germination of weed seeds without being thick enough to suppress their emergence. And any mulch, even a thin one, makes hoeing virtually impossible, while hand weeding through mulch is tedious.

Mulch has some unqualified pluses in hotter climates. Most of the organic matter in soil and consequently most of the available nitrogen is found in the surface few inches. Levels of other mineral nutrients are usually two or three times as high in the topsoil as well. However, if the surface few inches of soil becomes completely desiccated, no root activity will occur there and the plants are forced to feed deeper, in soil far less fertile. Keeping the topsoil damp does greatly improve the growth of some shallow-feeding species such as lettuce and radishes. But with our climate's cool nights, most vegetables need the soil as warm as possible, and the cooling effect of mulch can be as much a hindrance as a help. I've tried mulching quite a few species while dry gardening and found little or no improvement in plant growth with most of them. Probably, the enhancement of nutrition compensates for the harm from lowering soil temperature. Fertigation is better all around.

Keeping the Subsoil Open with Green Manuring

When roots decay, fresh organic matter and large, long-lasting passageways can be left deep in the soil, allowing easier air movement and facilitating entry of other roots. But no cover crop that I am aware of will effectively penetrate firm plowpan or other resistant physical obstacles. Such a barrier forces all plants to root almost exclusively in the topsoil. However, once the subsoil has been mechanically fractured the first time, and if recompaction is avoided by shunning heavy tractors and other machinery, green manure crops can maintain the openness of the subsoil.

To accomplish this, correct green manure species selection is essential. Lawn grasses tend to be shallow rooting, while most regionally adapted pasture grasses can reach down about 3 feet at best. However, orchard grass (called coltsfoot in English farming books) will grow down 4 or more feet while leaving a massive amount of decaying organic matter in the subsoil after the sod is tilled in. Sweet clover, a biennial legume that sprouts one spring then winters over to bloom the next summer, may go down 8 feet. Red clover, a perennial species, may thickly invade the top 5 feet. Other useful subsoil busters include densely sown Umbelliferae such as carrots, parsley, and parsnip. The chicory family also makes very large and penetrating taproots.

Though seed for wild chicory is hard to obtain, cheap varieties of endive (a semicivilized relative) are easily available. And several pounds of your own excellent parsley or parsnip seed can be easily produced by letting about 10 row feet of over wintering roots form seed. Orchard grass and red clover can be had quite in expensively at many farm supply stores. Sweet clover is not currently grown by our region's farmers and so can only be found by mail from Johnny's Selected Seeds. Poppy seed used for cooking will often sprout. Sown densely in October, it forms a thick carpet of frilly spring greens underlaid with countless massive taproots that decompose very rapidly if the plants are tilled in in April before flower stalks begin to appear. Beware if using poppies as a green manure crop: be sure to till them in early to avoid trouble with the DEA or other authorities.

For country gardeners, the best rotations include several years of perennial grass-legume-herb mixtures to maintain the openness of the subsoil followed by a few years of vegetables and then back. I plan my own garden this way. In October, after a few inches of rain has softened the earth, I spread 50 pounds of agricultural lime per 1,000 square feet and break the thick pasture sod covering next year's garden plot by shallow rotary tilling. Early the next spring I broadcast a concoction I call "complete organic fertilizer", till again after the soil dries down a bit, and then use a spading fork to open the subsoil before making a seedbed. The first time around, I had to break the century-old plowpan--forking compacted earth a foot deep is a lot of work. In subsequent rotations it is much much easier.

For a couple of years, vegetables will grow vigorously on this new ground supported only with a complete organic fertilizer. But vegetable gardening makes humus levels decline rapidly. So every few years I start a new garden on another plot and replant the old garden to green manures. I never remove vegetation during the long rebuilding under green manures, but merely mow it once or twice a year and allow the organic matter content of the soil to redevelop. If there ever were a place where chemical fertilizers might be appropriate around a garden, it would be to affordably enhance the growth of biomass during green manuring.

Were I a serious city vegetable gardener, I'd consider growing vegetables in the front yard for a few years and then switching to the back yard. Having lots of space, as I do now, I keep three or four garden plots available, one in vegetables and the others restoring their organic matter content under grass.

Using Humus to Increase Soil Moisture

Maintaining topsoil humus content in the 4 to 5 percent range is vital to plant health, vital to growing more nutritious food, and essential to bringing the soil into that state of easy workability and cooperation known as good tilth. Humus is a spongy substance capable of holding several times more available moisture than clay. There are also new synthetic, long-lasting soil amendments that hold and release even more moisture than humus. Garden books frequently recommend tilling in extraordinarily large amounts of organic matter to increase a soil's water-holding capacity in the top few inches.

Humus can improve many aspects of soil but will not reduce a garden's overall need for irrigation, because it is simply not practical to maintain sufficient humus deeply enough. Rotary tilling only blends amendments into the top 6 or 7 inches of soil. Rigorous double digging by actually trenching out 12 inches and then spading up the next foot theoretically allows one to mix in significant amounts of organic matter to nearly 24 inches. But plants can use water from far deeper than that. Let's realistically consider how much soil moisture reserves might be increased by double digging and incorporating large quantities of organic matter.

A healthy topsoil organic matter level in our climate is about 4 percent. This rapidly declines to less than 0.5 percent in the subsoil. Suppose inches-thick layers of compost were spread and, by double digging, the organic matter content of a very sandy soil were amended to 10 percent down to 2 feet. If that soil contained little clay, its water-holding ability in the top 2 feet could be doubled. Referring to the chart "Available Moisture" earlier, we see that sandy soil can release up to 1 inch of water per foot. By dint of massive amendment we might add 1 inch of available moisture per foot of soil to the reserve. That's 2 extra inches of water, enough to increase the time an ordinary garden can last between heavy irrigations by a week or 10 days.

If the soil in question were a silty clay, it would naturally make 21/2 inches available per foot. A massive humus amendment would increase that to 3 1/2 inches in the top foot or two, relatively not as much benefit as in sandy soil. And I seriously doubt that many gardeners would be willing to thoroughly double dig to an honest 24 inches.

Trying to maintain organic matter levels above 10 percent is an almost self-defeating process. The higher the humus level gets, the more rapidly organic matter tends to decay. Finding or making enough well-finished compost to cover the garden several inches deep (what it takes to lift humus levels to 10 percent) is enough of a job. Double digging just as much more into the second foot is even more effort. But having to repeat that chore every year or two becomes downright discouraging. No, either your soil naturally holds enough moisture to permit dry gardening, or it doesn't.