A great way to re-purpose an old stock tank is by turning it into a container garden. New stock tanks make interesting garden containers as well, available in several shapes, depths and sizes for added architectural appeal. Stock tanks are large, durable, rust-resistant and readily transformed into raised, compact and easily accessible garden beds. The metallic look also offers a nice visual contrast to your flowers, vegetables, herbs and garden decor.
Puncture several drainage holes into the bottom of your stock tank using a hammer and metal stake or an electric drill with at least a ¾" drill bit. For smaller tanks, 50 gallon capacity or less, three to four holes should be sufficient. Larger stock tanks will require more, the number depending upon its size. Cover any large holes with wire mesh or screen to prevent rodents from burrowing their way in.
Line the tank with plastic sheeting to prevent zinc from leaching into the soil. Large amounts of zinc in your soil can inhibit plant growth. After lining, make sure to puncture drainage holes into the plastic as well.
Fill tank with soil or compost of your choice. One of the great aspects of container gardening is the control you have over your soil, eliminating the need for fighting tree roots and poor quality soil. Your soil should offer good drainage while keeping the roots moist enough for adequate growth. If you choose, you can make your own potting soil by combining equal parts peat moss, package potting soil and sand.
Plant your flowers, vegetables, herbs or decorative plants, choosing varieties or combinations that are appropriate to the size of your tank. You want your plants to fill the tank will without looking or actually being overcrowded. Popular plant options include tomatoes, eggplant, herbs or various annuals combined with ornamental grasses.