Set tomato plants in the ground on the outside, and within 2 inches of the base of the wire. A 3 foot wide cage will allow room for 4 plants to be evenly spaced around the outside edge. Mulch the plants with a 3 inch layer of leaves. Also, mulch a 2 foot wide band around the base of the cage. Keep plants watered until they are well established and the roots begin to grow into the material inside the cage.
Subsequent irrigation is done by applying water to the top, in the center of the pile.
This allows for complete watering and movement of the fertilizer without wetting the foliage and stems. Click on image to see larger view This system has several other advantages. The alternating layers of compost and leaves provide a highly organic medium and plenty of air for the roots. And, no separate staking is required. As plants grow, simply tie them to the wire.