PREPARE THE CANVAS
Incorporate finely ground dolomitic limestone and an extremely generous helping of compost or well-rotted manure (containing little or no straw) into the top 8 to 12 inches of soil. The amount of limestone should be determined by a soil pH test conducted by the Cornell Cooperative Extension offices in East Meadow (516-228-0426 ext. 7) or Riverhead (631-581-4223) or with a testing kit, available at most garden centers. This can be done in fall for the following growing season or in spring, as soon as the soil is soft enough to till.
One application of a slow-release organic fertilizer at planting time and another when fruit first sets should keep tomatoes well-nourished throughout the growing season. Look for a product with a nutritional analysis of 5-10-5 and apply 4 to 5 pounds per 100 square feet of garden space. Ten, the middle number, indicates the percentage of phosphorus in the product, which is what aids fruit production. If you feel it's necessary, a third application can be made in late July or early August.
KILL THEM SUCKERS
Remove all the suckers, which are the small stems that grow between the branch crotches, as they appear. This will force the plant into a stockier, bushy shape and maximize photosynthesis so that more energy is directed to fruit production.
SURVIVAL OF THE FITTEST
Around the beginning of July, remove all but the largest fruit in each grouping of tomatoes at the top of the plant. Remove all tomatoes from the bottom of the plant. This should leave you with just three or four tomatoes per plant.
NIP THEM IN THE BUD, LITERALLY
Remove all the remaining flowers from the plant, as well as all future blossoms, to allow the plant to concentrate its energy on growing the remaining tomatoes instead of producing more.
Because tomato plants require consistent irrigation throughout the entire season, do not allow the soil to dry out between waterings. Give them 1 to 1 1/2 inches of water per week by weaving a soaker hose around the plants, directed at the roots, to keep the soil consistently moist but never soggy.