Automatic garden (yes, you read correctly) pays off big

For two years I had promised myself a visit to this beautiful Bucks County region of Pennsylvania to see, among other things, the low-work, high-productivity garden of Derek Fell. It was worth the effort.

Alhough it was mid-September and the garden was past its best, the evidence of a plentiful harvest was still obvious.

Mr. Fell is a long-established horticultural consultant, writer, and photographer. Among other things he planned the White House kitchen garden in the days when President Ford was talking up back-yard food production in his bite-the-bullet talks to the nation. He's also the author of several books.

The point is, Mr. Fell's duties take him away from home a good deal and the time he can devote to his garden is a fraction of what he would like it to be. That's why he decided two years ago to automate his garden. It was either automate or cut his garden down to a sliver of its former size.

Most important, his new approach was both simple and inexpensive.

Those two readily available, and still relatively inexpensive, products - black plastic and drip irrigation hose - made it all possible. As Mr. Fell puts it: ''By making my garden automatic, I achieved greater success from less work. It allowed me to plant a bigger-than-normal garden and to grow and harvest vegetables, such as sweet corn and cantaloupes, that previously had been difficult for me to grow.

''Everything in the garden grew bigger and more flavorful than before.''

In short, gardener Fell got better-than-expected results from automation so that he would ''continue the practice even if I had all the time in the world to garden.'' The records he kept - retail prices at time of harvest - show a $695 return on an $85 investment during the 1980 season.

Here is how the automatic garden was made:

Fell chose a sunny site with good drainage and tilled over an area, 20 by 42 feet, adding lime to his somewhat acid soil (add sulfur if yours is an alkaline soil) and a sprinkling of granular 5-10-5 fertilizer. To this he added an inch of well-rotted compost and tilled it to further enrich the soil and improve it.

Then he worked this soil into two-foot-wide beds, some four inches high and flattened on the top. The beds were raised by taking soil from the one-foot- wide paths which separated each bed, adding it to the growing area.

Then he laid 300 feet of drip-irrigation hose (150 feet on each side of the hose connecting it to the faucet), running it down the center of each bed and winding it from bed to bed. Drip-irrigation hose is sold in 50- and 100-foot lengths so he simply joined a shorter and longer length together to make the two 150-foot-length hoses which he needed.

Finally, each bed was covered with black plastic sheeting, held in place by burying the edges under the soil in the paths. He then added a straw mulch to the paths to keep them from getting muddy in wet periods.

The plastic did several things for the Fell garden. It prevented all weeds from growing, for example, thus cutting down dramatically on the time that would otherwise be devoted to weeding. It also warmed the soil early in the spring to get more rapid growth from the plants early in the season (by the time the summer sun rose high, the plastic was shaded by the lush vegetation so that it never got too hot for the plants). The plastic also conserved vital moisture by preventing evaporation.

When it came time to plant, Fell simply cut holes in the plastic where the seeds or seedling were to go. These holes were cut on either side of the irrigation hose for compact plants, such as lettuce, strawberries, bush beans, and corn (the holes ranged from 6 inches to 18 inches apart depending on the spacing needs of the plant).

Larger plants - tomatoes, peppers, and summer squash - required one row of planting holes down the center of the bed and just to one side of the hose.

Black plastic was omitted from the bed growing root crops, such as carrots, beets, and radishes. When these germinated and had become established, a straw mulch was laid down between the young plants to discourage weeds.

After the initial effort of planting, work in the garden was minimal. Once a week Fell left the drip-irrigation hose on overnight so that the beds were thoroughly soaked; and during periods of very wet weather even this was omitted because much of the rain soaked into the beds from the paths and through the planting holes. Every two weeks he sprayed a dilute foliar fertilizer on the plants. To guard against slugs, which enjoy the ideal moist conditions of the beds, he sprinkled slug pellets. He has had no other insect problems of any consequence.

This is what Fell harvested from his garden beds that first year (each 2 feet wide by 20 feet long): Beds 1 and 2 - 112 ears of sweet corn; Bed 3 - 200 pounds of tomatoes; Bed 4 - 190 pounds of summer squash; Bed 5 - 20 pounds of snap beans and 38 heads of lettuce; Bed 7 - 24 heads of cabbage, 24 heads of Chinese cabbage; Bed 8 - 132 pounds of potatoes; Bed 9 - 38 heads of lettuce and 22 pounds of spinach; Bed 10 - 36 pints of strawberries; Bed 11 - 12 pounds of peppers and 24 pounds of eggplant; Bed 13 - 42 cantaloupes; and finally, Bed 14 - 36 pounds of snap peas and 20 pounds of snap beans. Total value, according to Mr. Fell's figuring: $695.26.

Against this, his out-of-pocket expenses were: Drip-irrigation hose ($40 amortized over 3 years), $13.33; shut-off Y valve ($2.95 amortized over 3 years) , 98 cents; black plastic (300 feet, 3 feet wide), $12; 10 pounds granular fertilizer $3.95; 1 pound foliar fertilizer, $4.25; 10 pounds granulated limestone, $5; rotiller rental ($20 amortized over 3 years), $6.67; seeds, $23. 87; quart sprayer ($15.74 amortized over 3 years), $5.25; tomato towers ($21 amortized over 3 years), $7; and chicken wire pea support ($10 amortized over 3 years), $3.33. Total cost $85.63.

Not a bad deal, by my way of figuring. That's a pretty good return on your money these days.