Preparing the soil
Tomato plants grow best in well drained, moderately acidic to neutral soil (pH 6.0 to 6.8 is optimum) with a good level of soil organic matter.
Soil with pH below 5.5 requires application of agricultural lime to increase the pH to a level more favorable for plant growth. Soil in high-rainfall areas often
requires lime to increase the calcium supply. For tomato, adequate available soil calcium is needed to prevent blossom end rot, which is a large black spot that forms on the bottom of tomato fruits in calcium-deficient soils, or when drought stress limits calcium translocation
within the plant.
Low levels of available soil phosphorus limit plant growth in many of Hawaii’s soils. Both lime and phosphate fertilizer must be mixed thoroughly into the surface 6–8 inches of the soil before planting.
Fertilizer application to the bearing crop
When the plants begin to flower, apply the second dose of general fertilizer, in the case of determinate types, or begin the smaller biweekly applications to indeterminate types. Divide the amount of fertilizer being applied according to the number of plants in a 100 sq ft garden area, and apply it 6–8 inches from the base of each plant. Some gardeners spread the fertilizer on the soil surface, but others believe it is best to use a trowel to incorporate it 2–4 inches into the soil in one or two spots, using care to minimize damage to the plant root system. Irrigate after the application. Water-soluble fertilizers containing micronutrients may also be used for postplanting applications.