Gardening Without Irrigation Part 9

In 1991 we had about 2 surprising inches of rain late in June, so as a test I sowed rutabagas on July 1. They germinated without more irrigation, but going into the hot summer as small plants with limited root systems and no irrigation at all they became somewhat stunted. By October 1 the tops were still small and a little gnarly; big roots had not yet formed. Then the rains came and the rutabagas began growing rapidly. By November there was a pretty nice crop of medium-size good-eating roots.

I suspect that farther north, where evaporation is not so severe and midsummer rains are slightly more common, if a little irrigation were used to start rutabagas about July 1, a decent unwatered crop might be had most years. And I am certain that if sown at the normal time (July 15) and grown with minimal irrigation but well s.p.a.ced out, they'll produce acceptably.

_Varieties:_ Stokes Altasweet (STK, TSC) has the best flavor.

Sorrel

This weed-like, drought-tolerant salad green is little known and underappreciated. In summer the leaves get tough and strong flavored; if other greens are available, sorrel will probably be unpicked. That's ok. During fall, winter, and spring, sorrel's lemony taste and delicate, tender texture balance tougher savoy cabbage and kale and turn those crude vegetables into very acceptable salads. Serious salad-eating families might want the production of 5 to 10 row-feet.

_Sowing date:_ The first year you grow sorrel, sow mid-March to mid-April. The tiny seed must be placed shallowly, and it sprouts much more readily when the soil stays moist. Plant a single furrow centered in a row 4 feet wide.

_s.p.a.cing: _As the seedlings grow, thin gradually. When the leaves are about the size of ordinary spinach, individual plants should be about 6 inches apart.

_Irrigation:_ Not necessary in summer--you won't eat it anyway. If production lags in fall, winter, or spring, side-dress the sorrel patch with a little compost or organic fertilizer.

_Maintenance:_ Sorrel is perennial. If an unusually harsh winter freeze kills off the leaves it will probably come back from root crowns in early spring. You'll welcome it after losing the rest of your winter crops. In spring of the second and succeeding years sorrel will make seed. Seed making saps the plant's energy, and the seeds may naturalize into an unwanted weed around the garden. So, before any seed forms, cut all the leaves and seed stalks close to the ground; use the tr.i.m.m.i.n.gs as a convenient mulch along the row.

If you move the garden or want to relocate the patch, do not start sorrel again from seed. In any season dig up a few plants, divide the root ma.s.ses, trim off most of the leaves to reduce transplanting shock, and transplant 1 foot apart. Occasional unique plants may be more reluctant to make seed stalks than most others. Since seed stalks produce few edible leaves and the leaves on them are very harsh flavored, making seed is an undesirable trait. So I propagate only seed-shy plants by root cuttings.

Spinach

Spring spinach is remarkably more drought tolerant than it would appear from its delicate structure and the succulence of its leaves.

A bolt-resistant, long-day variety bred for summer harvest sown in late April may still yield pickable leaves in late June or even early July without any watering at all, if thinned to 12 inches apart in rows 3 feet apart.

Squash, Winter and Summer

_Sowing date:_ Having warm-enough soil is everything. At Elkton I first attempt squash about April 15. In the Willamette, May 1 is usual. Farther north, squash may not come up until June 1. Dry gardeners should not transplant squash; the taproot must not be broken.

_s.p.a.cing:_ The amount of room to give each plant depends on the potential of a specific variety's maximum root development. Most vining winter squash can completely occupy a 10-foot-diameter circle. Sprawly heirloom summer squash varieties can desiccate an 8-or 9-foot-diameter circle. Thin each hill to one plant, not two or more as is recommended in the average garden book. There must be no compet.i.tion for water.

_Irrigation:_ With winter storage types, an unirrigated vine may yield 15 pounds of squash after occupying a 10-foot-diameter circle for an entire growing season. However, starting about July 1, if you support that vine by supplying liquid fertilizer every two to three weeks you may harvest 60 pounds of squash from the same area. The first fertigation may only need 2 gallons. Then mid-July give 4; about August 1, 8; August 15, feed 15 gallons. After that date, solar intensity and temperatures decline, growth rate slows, and water use also decreases. On September 1 I'd add about 8 gallons and about 5 more on September 15 if it hadn't yet rained significantly.

Total water: 42 gallons. Total increase in yield: 45 pounds. I'd say that's a good return on water invested.

_Varieties:_ For winter squash, all the vining winter varieties in the C. maxima or C. pepo family seem acceptably adapted to dry gardening. These include b.u.t.tercup, Hubbard, Delicious, Sweet Meat, Delicata, Spaghetti, and Acorn. I wouldn't trust any of the newer compact bush winter varieties so popular on raised beds. Despite their reputation for drought tolerance C. mixta varieties (or cushaw squash) were believed to be strictly hot desert or humid-tropical varieties, unable to mature in our cool climate. However, Pepita (PEA) is a mixta that is early enough and seems entirely unbothered by a complete lack of irrigation. The enormous vine sets numerous good keepers with mild-tasting, light yellow flesh.

Obviously, the compact bush summer squash varieties so popular these days are not good candidates for withstanding long periods without irrigation. The old heirlooms like Black Zucchini (ABL) (not Black Beauty!) and warty Yellow Crookneck grow enormous, high-yielding plants whose extent nearly rivals that of the largest winter squash.

They also grow a dense leaf cover, making the fruit a little harder to find. These are the only American heirlooms still readily available. Black Zucchini has become very raggedy; anyone growing it should be prepared to plant several vines and accept that at least one-third of them will throw rather off-type fruit. It needs the work of a skilled plant breeder. Yellow Crookneck is still a fairly "clean" variety offering good uniformity. Both have more flavor and are less watery than the modern summer squash varieties. Yellow Crookneck is especially rich, probably due to its thick, oily skin; most gardeners who once grow the old Crookneck never again grow any other kind. Another useful drought-tolerant variety is Gem, sometimes called Rolet (TSC). It grows an extensive winter-squash-like vine yielding grapefruit-size, excellent eating summer squash.

Both Yellow Crookneck and Black Zucchini begin yielding several weeks later than the modern hybrids. However, as the summer goes on they will produce quite a bit more squash than new hybrid types. I now grow five or six fully irrigated early hybrid plants like Seneca Zucchini too. As soon as my picking bucket is being filled with later-to-yield Crooknecks, I pull out the Senecas and use the now empty irrigated s.p.a.ce for fall crops.

Tomato

There's no point in elaborate methods--trellising, pruning, or training--with dry-gardened tomato vines. Their root systems must be allowed to control all the s.p.a.ce they can without compet.i.tion, so allow the vines to sprawl as well. And pruning the leaf area of indeterminates is counterproductive: to grow hugely, the roots need food from a full complement of leaves.

_Sowing date:_ Set out transplants at the usual time. They might also be jump started under cloches two to three weeks before the last frost, to make better use of natural soil moisture.

_s.p.a.cing:_ Depends greatly on variety. The root system can occupy as much s.p.a.ce as the vines will cover and then some.

_Irrigation:_ Especially on determinate varieties, periodic fertigation will greatly increase yield and size of fruit. The old indeterminate sprawlers will produce through an entire summer without any supplemental moisture, but yield even more in response to irrigation.

_Variety:_ With or without irrigation or anywhere in between, when growing tomatoes west of the Cascades, nothing is more important than choosing the right variety. Not only does it have to be early and able to set and ripen fruit when nights are cool, but to grow through months without watering the plant must be highly indeterminate. This makes a built-in conflict: most of the sprawly, huge, old heirloom varieties are rather late to mature. But cherry tomatoes are always far earlier than big slicers.

If I had to choose only one variety it would be the old heirloom [Large] Red Cherry. A single plant is capable of covering a 9- to 10-foot-diameter circle if fertigated from mid-July through August.

The enormous yield of a single fertigated vine is overwhelming.

Red Cherry is a little acid and tart. Non-acid, indeterminate cherry types like Sweetie, Sweet 100, and Sweet Millions are also workable but not as aggressive as Red Cherry. I wouldn't depend on most bush cherry tomato varieties. But our earliest cherry variety of all, OSU's Gold Nugget, must grow a lot more root than top, for, with or without supplemental water, Gold Nugget sets heavily and ripens enormously until mid-August, when it peters out from overbearing (not from moisture stress). Gold Nugget quits just about when the later cherry or slicing tomatoes start ripening heavily.

Other well-adapted early determinates such as Oregon Spring and Santiam may disappoint you. Unless fertigated, they'll set and ripen some fruit but may become stunted in midsummer. However, a single indeterminate Fantastic Hybrid will cover a 6-to 7-foot-diameter circle, and grow and ripen tomatoes until frost with only a minimum of water. I think Stupice (ABL, TSC) and Early Cascade are also quite workable (and earlier than Fantastic in Washington).

Chapter 6

My Own Garden Plan

This chapter ill.u.s.trates and explains my own dry garden. Any garden plan is a product of compromises and preferences; mine is not intended to become yours. But, all modesty aside, this plan results from 20 continuous years of serious vegetable gardening and some small degree of regional wisdom.

My wife and I are what I dub "vegetablitarians." Not vegetarians, or lacto-ovo vegetarians because we're not ideologues and eat meat on rare, usually festive occasions in other peoples' houses. But over 80 percent of our calories are from vegetable, fruit, or cereal sources and the remaining percentage is from fats or dairy foods.

The purpose of my garden is to provide at least half the actual calories we eat year-round; most of the rest comes from home-baked bread made with freshly ground whole grains. I put at least one very large bowl of salad on the table every day, winter and summer. I keep us in potatoes nine months a year and produce a year's supply of onions or leeks. To break the dietary monotony of November to April, I grow as wide an a.s.sortment of winter vegetables as possible and put most produce departments to shame from June through September, when the summer vegies are "on."

The garden plan may seem unusually large, but in accordance with Solomon's First Law of Abundance, there's a great deal of intentional waste. My garden produces two to three times the amount of food needed during the year so moochers, poachers, guests, adult daughters accompanied by partners, husbands, and children, mistakes, poor yields, and failures of individual vegetables are inconsequential. Besides, gardening is fun.

My garden is laid out in 125-foot-long rows and one equally long raised bed. Each row grows only one or two types of vegetables. The central focus of my water-wise garden is its irrigation system. Two lines of low-angle sprinklers, only 4 feet apart, straddle an intensively irrigated raised bed running down the center of the garden. The sprinklers I use are Naans, a unique Israeli design that emits very little water and throws at a very low angle (available from TSC and some garden centers). Their maximum reach is about 18 feet; each sprinkler is about 12 feet from its neighbor. On the garden plan, the sprinklers are indicated by a circle surrounding an "X." Readers unfamiliar with sprinkler system design are advised to study the irrigation chapter in Growing Vegetables West of the Cascades.

On the far left side of the garden plan is a graphic representation of the uneven application of water put down by this sprinkler system. The 4-foot-wide raised bed gets lots of water, uniformly distributed. Farther away, the amount applied decreases rapidly.

About half as much irrigation lands only 6 feet from the edge of the raised bed as on the bed itself. Beyond that the amount tapers off to insignificance. During summer's heat the farthest 6 feet is barely moistened on top, but no water effectively penetrates the dry surface. Crops are positioned according to their need for or ability to benefit from supplementation. For convenient description I've numbered those rows.

The Raised Bed

Crops demanding the most water are grown on the raised bed. These include a succession of lettuce plantings designed to fill the summer salad bowl, summer spinach, spring kohlrabi, my celery patch, scallions, Chinese cabbages, radishes, and various nursery beds that start overwintered crops for transplanting later. Perhaps the bed seems too large just for salad greens. But one entire meal every day consists largely of fresh, raw, high-protein green leaves; during summer, looseleaf or semiheading lettuce is our salad item of choice. And our individual salad bowls are larger than most families of six might consider adequate to serve all of them together.

If water were severely rationed I could irrigate the raised bed with hose and nozzle and dry garden the rest, but as it is, rows 1, 2, 7, and 8 do get significant but lesser amounts from the sprinklers.

Most of the rows hold a single plant family needing similar fertilization and handling or, for convenience, that are sown at the same time.

Row 1

The row's center is about 3 feet from the edge of the raised bed. In March I sow my very first salad greens down half this row--mostly a.s.sorted leaf lettuce plus some spinach--and six closely s.p.a.ced early Seneca Hybrid zucchini plants. The greens are all cut by mid-June; by mid-July my better-quality Yellow Crookneck squash come on, so I pull the zucchini. Then I till that entire row, refertilize, and sow half to rutabagas. The nursery bed of leek seedlings has gotten large enough to transplant at this time, too.

These go into a trench dug into the other half of the row. The leeks and rutabagas could be reasonably productive located farther from the sprinklers, but no vegetables benefit more from abundant water or are more important to a self-sufficient kitchen. Rutabagas break the winter monotony of potatoes; leeks vitally improve winter salads, and leeky soups are a household staple from November through March.

Row 2: Semi-Drought Tolerant Bra.s.sicas