The EarthBox Company claims that their plant-growing system, which goes by the same name, is simple to use and produces at least double the produce yield that a regular garden plot produces. This enclosed cultivator has certainly won many fans, but it does come with a few challenges.
How the EarthBox Works
The EarthBox is a model of simplicity. There are four basic pieces: a plastic container, a screen, a pipe and a thin plastic liner. The screen lines the bottom of the tub, creating a space for a reservoir of water below the soil. The pipe, set upright in one corner, allows the user to refill the reservoir. After loading the system with potting soil and fertilizer, plants go through holes in the liner at the top, which slows moisture evaporation.
Once the box is loaded, the gardener waters from the top thoroughly once, to start the capillary action of the soil and draw the water from the bottom, which the gardener occasionally refreshes from the pipe. An overflow outlet ensures that the roots don't drown. The system also comes with optional casters so it can be moved more easily.
The roots of plants in the EarthBox enjoy almost total protection from weeds, burrowing nuisances like moles and gophers, soil-borne pests like cutworms and slugs, and fungi that cause wilts. Moved far enough away from the regular plot, many insects won't find the foliage, either. The system also requires much less water. The reservoir holds a reserve that won't leak away from the root zone like regular ground. The cover prevents almost all evaporation.
Container gardening, which includes the EarthBox, is also perfect for areas where sun and soil do not meet, like an apartment balcony or a property with lots of trees. And plants can easily move indoors if there's an unexpected late frost.
The EarthBox has black and white sides to absorb or reflect sunlight, depending on the heat of your climate, but the rest of the box itself is dark green, so the roots could still be vulnerable to overheating in some areas.
The system is also very picky about the type of soil it can use, which must promote the capillary action necessary to draw the water up to the roots. This means only fine, light potting soil works. It would be almost impossible to use your own compost. The company insists that if you purchase potting soil, you'll be able to use it in the system up to five times before needing to replace it--but it will need to be recharged with some fertilizer.
Don't let the system dry out, either: If the soil loses moisture, the water supply to the roots shuts down, even if you refill the reservoir. Then you have to water from the top again, a tricky proposition if plants have grown so much that the cover can't be removed easily.
Potting soil isn't the only expense. The unit itself retails for about $50 (as of 2009). Since the concept is so simple, some garage tinkerers have figured out how to make their own, cheaper homemade units. Still, even the cheapest materials cost more than a humble backyard vegetable patch.
Vegetable Patch Advantages
A regular backyard plot still has much to offer. There are plenty of organic means to eradicating pests in a vegetable garden bed, or at least bringing them down to acceptable levels. Row covers can handle most late frosts. Gardening in the ground is sheer sustainability; the spent plants from the plot become the compost that will fertilize the soil for the next round. Mulch, like leaves, can slow water evaporation, and humus rich in leaf mold can retain more water for roots. When you're working a plot, you're cooperating with the whole ecosystem, you're getting food for less than a tenth of the regular cost, and you generally have more room for growing things.
Vegetable Patch Disadvantages
A vegetable patch is much more labor-intensive. Weeding, composting, pest-control measures and soil preparation generally don't exist for users of the EarthBox. You'll be watering more, too.
Ultimately, the vegetable patch vs. EarthBox debate really comes down to labor vs. expense. But it really doesn't have to be an either/or proposition. The EarthBox may be ideal for plants that are especially vulnerable to infestation, like tomato strains that lack fusarium wilt resistance. The vegetable bed is fine for hardier crops. Many gardeners use both systems.