Engineer tweaks self-watering container garden system

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When the EarthBox came onto the market several years ago, it was aninstant success with home gardeners who loved the promise of easy,small-space container gardening.

Hundreds of thousands of EarthBoxes - originally marketed as "thegarden of the future" - have been sold, and the contraptioncontinues to be wildly popular.

After all, what's not to like? The EarthBox promises no digging inthe dirt, no weeding and no fertilizing, and the bottom-up,self-watering system forgives many sins.

But it wasn't long before tinkerers and tweakers began fiddlingwith the EarthBox concept, using everything from washtubs to bigbuckets to replicate its good features and improve on its perceivedshortcomings.

Plans for home-built EarthBox-like gizmos are all over theInternet, and ideas are regularly swapped on gardenrelated forumsonline. And there are several knock-offs available in retail storesand on the Web.

Campbell, Calif., gardener Ray Newstead was fascinated by theclosed-system, water-saving aspects of the EarthBox but decided itwas too small to contain the large beefsteak-type tomatoes he hasgrown for years in the ground and in raised beds.

He also was not impressed with the caging system sold as anaccessory to the EarthBox, which he says isn't sturdy enough tosupport heavily producing tomato vines without danger of fallingover from being top-heavy or being blown over in high winds.

So Newstead - by day, an electrical engineer and executive in SanJose with semiconductor company SMSC - went to work.

He started by looking at some of the designs posted on the Web.

But then his innovation DNA kicked in, and pretty soon - through aprocess of trial and error that he has shared freely with theonline community - he came up with an ingenious design for thegrowing box and its caging system that uses off-the-shelfcomponents, but incorporates a proprietary accessory of theEarthBox setup he purchases from that company. He calls his versionthe EarthTainer, and he has applied for a patent.

Newstead's back yard now sports 26 of these big boxes. Two dozen ofthem hold two tomato plants each; in the other two, he's growingcorn.
"My biggest question about the EarthBox was: How can I super-sizeit?" Newstead says.

At Wal-Mart and other big-box retailers, he prowled the housewaresaisles and came upon some taupe-colored 31-gallon RubbermaidRoughneck lidded storage containers. At 16 1 /2 inches tall, theyare 5 1 /2 inches taller than the EarthBox (and longer by 3 inchesand wider by 6).

When tricked out as an EarthTainer, the Roughnecks hold about 10gallons of water in a 6-inch self-watering reservoir. The EarthBoxhas a 2-inch water reservoir.

"It's like a boat anchor," says Newstead, noting that a "fullyloaded" EarthTainer - filled with potting mix, plants and water -weighs about 150 pounds. "Just try to pull that over."

Each EarthTainer is made from two Roughnecks. One is cut down,drilled like Swiss cheese with many holes and inserted inside theother to create an "aeration bench" that holds the potting mix andplants over the water reservoir.

In between these two layers is a "wicking basket" made from anordinary 6-inch-tall pond filtration basket. The wicking basketsits on the floor of the bottom Rubbermaid container; its top helpssupport the shelf to create an air gap between the potting mix andthe water reservoir. A piece of plastic pipe serves as a fillertube for the reservoir.

Plants in the EarthTainer, like in the EarthBox, are supplied withwater through bottom-up capillary action.

The wicking basket, which is packed with potting mix, delivers thewater up to the bulk of the potting mix, where the plants grow.

"The plant takes up just as much water as it needs as long as youkeep the reservoir full," Newstead says. "You can't over- orunder-water. It's a closed-loop system."

The sturdy caging system he devised starts with heavy-duty 54-inchtomato cages made by Glamos Manufacturing and available atWal-Mart.

The cages, which have a diameter of 18 inches, are attached, two toan EarthTainer, using washers, wire rope clips and toggle bolts.The caging system integrates a black plastic moisture barrier,through which the tomato seedlings are planted. The lid of theRubbermaid container - the center removed - snaps on to hold themoisture barrier and stabilize the cages.

He also offers plans to build a cage extension for those really bigindeterminate tomatoes.

And what do the folks who came up with the EarthBox think aboutknock-offs like Newstead's?

It was inevitable, says Frank DiPaolo, general manager of EarthBox,based in Scranton, Penn.: "When we introduced the EarthBox, we knewwe had a revolutionary product and if it hadn't been successful,there wouldn't be competitive products today.

"In the marketplace, imitation really is the sincerest form offlattery."

Newstead estimates that his EarthTainer-grown tomatoes will consume75 percent less water than those cultivated in the ground or inraised beds.

Those savings will be particularly important this year, when thestate is facing a drought.

"This closed-loop design concentrates 100 percent of the water inthe reservoir to the plants," he says.

"I travel a lot for business, and when I grew my tomatoes in araised bed with a soaker hose, even with a timer I would inevitablyover-water and come back to weeds galore."

Plus, says Newstead, some tomato varieties are bigger drinkers thanothers.

"I was constantly fiddling with (the watering system)," he says."My Ed's Millennium was wanting a lot of water, while Carmelo, notso much. One-sizefits-all was not working."