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Build Your Own Trans-Potable Garden

By Peter TongeSpecial to The Christian Science Monitor / May 5, 1997



WEYMOUTH, MASS.

Two years ago drought gripped this corner of New England and water restrictions were in place everywhere, yet I grew bumper crops of tomatoes, peppers, and other vegetables without violating the law.

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The secret lay in the containers - barrels and tubs adapted so that they had reservoirs at the bottom.

On the hottest of days, moisture was never far from the probing roots of these plants. Even so the system used far less water than conventional gardening, because no water drained beyond the reach of the roots and I was able to keep the reservoirs filled using rain water collected during occasional showers.

Tubs make it possible to grow plants where there is no suitable soil. In my case, some of the sunniest areas are where tree roots make conventional gardening impossible. Once in place, these tub gardens virtually take care of themselves, apart from watering every few days.

Any container capable of holding water can be turned into a planter. I have used 32-gallon garbage barrels to wastepaper office bins. As an example, let's take a plastic bushel basket:

You will need some perforated drainage pipe, available from any lumber yard, some PVC tubing as a filler tube and a piece of cloth, preferably polyester because it won't rot. It also makes a very effective wick.

In most containers one layer of drainage pipe makes an adequate reservoir; in 32-gallon bins, place a second layer on top of the first to double the reservoir size.

Place a handful of compost in the bottom of each planting hole and resort to liquid fertilizing once the plants are growing strongly. Liquid fertilizer can also be poured directly into the reservoir. Dilute it to half strength and add a new batch once a week. Don't use an organic fertilizer in this fashion, such as fish emulsion. I once did and while the plants did well, I could smell the container from six feet away. Fish emulsion poured on top of the soil works just fine.

I will grow as many as three large indeterminate tomatoes in the 32-gallon barrels; two or one in the smaller bins. The medium-sized tubs hold two to three peppers and the same number of eggplants. Once a week I water each tub thoroughly from the top; otherwise I use the filler tube to top up the reservoir whenever needed.

Another Method of Fertilizing

ast year, I was sent a container system from EarthBox in St. Petersburg, Fla. To my amazement, it was a carbon copy of the tubs I adapted for my garden. It's 30 inches long-by-15 inches wide, holds 2.3 cubic feet of potting mix, and has a 2.2-gallon capacity reservoir. A screen over the reservoir allows air to the roots. But the way plants are fed in the EarthBox system differs from anything I had previously done with the tubs: Two cups of dry granular fertilizers are placed in a band across the soil surface and covered with plastic.

Normally such an amount of fertilizer in so small a space would burn plant roots. But the plastic covering prevents rain from dispersing the fertilizer through the planting medium, so plants send their roots all around the fertilizer band.

The effect is the same as an automated feeding system and the end results are impressive. I was so taken by the idea that all my container plants were fed this way last year.

1. Cut a piece of perforated drainage pipe so that it fits snugly from one side to the other across the bottom of the tub (don't be concerned if the fit isn't perfect).

2. Cut two smaller cross pieces so they fit between the sides of the tub and the piece of drainage pipe already installed. The drainage pipes will now form a cross at the bottom of the tub.

3. Drill a drainage hole in the side of the tub, about half an inch below the top of one of the drainage tubes. This acts as both a drainage and air-intake hole so that, even when full, air will be in the top half-inch of the pipe. With oxygen freely available at all times, there will never be a problem with root rot.

4. Cut a piece of PVC pipe an inch or so longer than the tub is deep. This will form the filler pipe so that water and liquid fertilizer can be poured directly into the reservoir from where it will wick up into the soil as needed.

5. Drill several holes in the bottom 5 inches of the PVC pipe and place it in one of the hollow sections between the drainage pipes.

6. Fill the rest of the hollow around this pipe with pebbles so that water poured down the pipe will freely enter the reservoir.

7. Cover the drainage pipes and the pebbles with a piece of polyester cloth to stop the growing mix from filtering into the reservoir.

8. Fill the tub with soil fortified with compost at a 4-1 ratio. The growing mixture, pressed down into the three hollows, acts, along with the cloth, as a wick to draw up the water to the plants.

9. Water the soil for settling. Top up if necessary and plant.

* For a brochure, phone 800 360-2299.