Crop Rotation

• Plant your baby tomato plant in a section where no tomatoes were grown in the past season to prevent any viruses that may still be in the soil from affecting your new plant. Rotate the crops in the square-foot garden to prevent disease and to use a part of the garden where the soil will not be depleted in nutrients from the last year's crop.
  
  

Sunlight

• Tomatoes need direct sunlight for at least seven hours a day, if not more. Situate your planting within the grid so that the plant is facing the south; it will get sunlight from the east in the morning and from the west in the evening for the maximum light exposure. Make sure there are no trees or shrubs in the area that might block the sunlight or you will grow bushy plants with little fruit.
  
  

Support

• Situate your tomato plants where the support structure will not block the sunlight from a large area of your garden, usually the north side and in a block on the outside edge of the square-foot garden structure. Give plenty of space around the trellis or cage -- at least 4 feet on all sides so that you have room to walk around it as well as space for the plant to grow.
  
  

Morning Sun

• The summer sun tends to be stronger in the afternoon. If you have to choose between morning or afternoon sun, plant your tomato plant on the east side of the garden in a section on the outside so it will receive morning sun and avoid afternoon sun scorch.