Much has been made of the fact that the potato plant can be encouraged to continuing growing longer and more productive root structure by gradually raising the soil level around the developing plant. Here at Extopian, we are going to share one more method to do so while, at the same time, finding new life for one of the biggest waste eyesores out there… the automobile tire. So gather your potato sprouts, recipes along; with those previously unsalvageable white walls and get ready to build your own high yield potato factory.

Why the Potato is Such a Useful Vegetable

The potato is one of the highest square-footage-used to nutrient-produced crops in the Western world. By nature, they are nutrient-producing and storing machines on scale that puts many other tubers to shame. During times of necessity, human beings can even survive in reasonable health on a diet of potatoes and milk alone.

In the potato’s native habit in the mountainous regions of western South America (NOT Ireland, grin) this plant formed the backbone of several civilizations.

The key to the potato’s usefulness and success lays in the environment it which it originated. It is well adapted to resist fluctuations in climate, storing large amounts of nutrients during lean times and possessing the ability to regenerate from predation and other damage from a single “eye” if need be.

Cultivating High Yield Potatoes

The potato plant stores a large portion of the nutrients below ground in its familiar tuber, instead of focusing primarily on fruits. Like all plants, it relies on sunlight for its fuel and will seek out sunlight in its growth patterns.

The layering method takes advantage of this trait by slowly increasing the level of the soil around the developing plant. This forces the plant to continue to grow upward to seek light while simultaneously encouraging the portions of the plant being covered with new soil to convert themselves to longer and larger, tuber-bearing root systems.

potato_plantThere are a couple popular methods used to create this effect. One employs large, heavy-ply trash bags, but I find this method wasteful as the bags are rarely reusable after harvest. 50-gallon barrels are sometimes used, but they limit sunlight in the early stages because of their depth. Building wood-frames up around the developing plant in stages is an excellent tactic, but it is also a lot of work.

While enjoying the gardening practices in my neighborhood, I noticed a few folks using old car tires as single-layer, above-ground planters for plants. It occurred to me that by planting a potato plant in this way, you could simply add additional tires and soil until you had quite a formidable planter depth. Four to five feet is sufficient without risking water-retention or stability issues.

Obviously, discarded tires are best for this process as roadsides and junkyards have no shortage of them. They don’t have to be in perfect shape, but should be similar in size to keep your stacks stable. Avoid tires that have been stored in areas with high levels of standing oil or gasoline. A quick olfactory inspection should reveal tires made unsuitable by these conditions. A piece of pipe or 2×4 driven into the ground perpendicularly can help stabilize the tire planter if you’re concerned about shifting or collapse.

The fact that your sections are not a single, solid unit will encourage good drainage and respiration. Holes can be drilled into lower tires to improve this or monitor soil at lower depths, if desired. Additionally, the dark color of tires encourages the absorption of sunlight, helping to protect your plants from cold snaps.

When harvest time comes, simply remove or knock away the tires one layer at a time. By the time you remove the 2nd or 3rd tire from the top, you should start to encounter potatoes. Stack your tires for reuse next season, and be diligent about not allowing water to collect in them, because in some climates standing water in empty tires serves as a breeding ground for mosquitoes and other pests.

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