For highest productivity Tomatoes need a steady supply of available water and nutrients. If you give them all they need, they will respond by flowering earlier and fruiting more profusely.

Water Needs

Moderate

These deep-rooted plants are quite drought tolerant and don't really need a lot of water once they are established. In fact, keeping them dry encourages strong root growth. However you will get more and larger fruit if you keep the soil evenly moist once they start flowering and bearing fruit.

Drip irrigation works well with tomatoes, as it keeps the soil evenly moist but the plants stay dry.

Uneven watering may cause Blossom End Rot or cracking.

Fertilizer Needs

Heavy

High nitrogen. Moderate phosphorus. High potassium. Tomatoes are quite heavy feeders. They have deep roots that may go down 5', but most of their feeder roots are in the top 2'.

Watering, regularly

Water, 1 gallon(s), regularly, 1 time a week

Water well after transplanting and keep the plants moist until they are well established.

Protecting, while danger of early frost

Row cover(s), 1 layer(s), while danger of early frost, 1 time

Put a cover over plants while danger of frost is present

This is important, as an early frost in fall will usually kill unprotected tomato plants. If you can help your plants make it through these first frosts there may not be another one for several weeks, during which time you can get a lot more ripe fruit. Almost anything can help them to survive a mild frost, old bed sheets, straw mulch, plastic sheet, or cardboard.

Protecting, while danger of late frost

Row cover(s), 1 layer(s), while danger of late frost, 1 time

If a late frost threatens after you've put out your transplants you can protect them with row cover. Almost anything can help them to survive a mild frost, old bed sheets, straw mulch, plastic sheet, cardboard.

Side Dressing, after planting

Mulch, 2 inch(es), after planting, 1 time

A mulch (2" of straw) is useful to keep down weeds, conserve moisture and keep the fruit clean. It can also reduce disease problems by keeping soil off of the foliage.

Don’t put down an organic mulch until the soil is warm (when plants start to flower), as it could insulate the soil and keep it cool.

Watering, during fruit production

Water, 1 gallon(s), during fruit production, 2 times a week

 Their most critical need for water is when the fruit is sizing up. Make sure the soil is kept moist at this time.

Side Dressing, during fruit production

Compost tea, 1 cup(s) per plant, during fruit production, every 3 weeks

If your soil isn't very fertile, you should give them a cup of diluted compost tea (or liquid kelp as directed) every 3 weeks when the plants start producing fruit. This is not necessary if your soil is very fertile.

Support

At planting

If you want to go for the easiest kind of support, with the most efficiency and the least effort, use a wire cage.

Indeterminate varieties should be staked, caged or trellised. Set the support at the time of planting. The plants can be trained, trimmed and tied in place on a regular basis.

You can let your plants grow without support, they can just sprawl on the ground. However when plants are supported the loss of fruit to disease, rotting, and pests is much less and one can grow more plants in a given area. As a result the harvest can be significantly larger.