1. Sunlight. Tomatoes require a minimum of 8 hours of continuous sunlight each day.
2. Temperature. Tomatoes need 3 to 4 months of warm, clear, fairly dry weather to produce best. Tomatoes need consistent night temperatures between 55°F and 75°F to set fruit. (A few varieties will set fruit at lower or higher temperatures.) Fruit will not color properly when night temperatures stay above 85°F, and plants will quit growing when temperatures go above 95°F.
3. Continuous and even watering. Keep the soil evenly moist–not too wet and not too dry. Too much water will drown the plant; too little water will stop fruit production. Test soil moisture by sticking your finger into the soil–if it comes out dry, it's time to water; if it comes out wet, hold off. During periods of drought deep water tomatoes once a week. A constant, even supply of water can prevent blossom end rot, but too much water will cause it.
4. Continuous feeding. Prepare the tomato-growing bed with well-rotted garden compost and a trowelful of aged manure added to the soil where each plant will grow. Add a trowelful of bone meal into the bottom of each hole–the extra phosphorus will speed ripening. Too much nitrogen will give you abundant foliage but delay ripening. Add nitrogen when the top leaves turn yellow and the stem become deep purple.
5. Loose, well-drained soil. But almost any garden soil will grow tomatoes. Sandy loam is best for early tomatoes. Heavy clay loam is ideal for late tomatoes. Amend the soil with aged compost before planting. Tomatoes prefer a soil with a pH between 6.0 and 7.0, just below neutral in acidity.
6. Protect leaves and roots. Protect the tomato plant from extremes of temperature–cold and hot, strong winds, weeds, pests and diseases. Set 8 to 10 week old tomato seedlings in the garden two weeks after the last frost in spring. If transplanted sooner, tomatoes must be protected from cold temperatures with hot caps or plastic tunnels. Place tomatoes in the garden where they will be protected from drying winds. Protect plants from cutworms with a paper collar set in the soil at transplanting. Examine plants often to be rid of tomato hornworms and other pest early. Avoid fungal and bacterial diseases by watering at the base of plants and rotating tomatoes to new beds each year. Where summer temperatures exceed 95°F, shade cloth protection will protect leaves and fruit.