You can grow a better vegetable garden, increasing the potential for stronger, more robust vegetables, by following a few steps before the first plant is set into the soil. You need organic matter, disease resistant vegetable plants, and mulch.
Before You Plant
Rake 4 to 6 inches of organic matter, like compost or leaf mold, onto the area of your garden. Use the rototiller to work the organic matter into the soil or use a shovel to turn the organic matter over. The organic matter will add nutrients to the soil.
Purchase disease resistant plants. They may cost a little more, but not having to deal with disease will make the slight added expense worth it. Rotate the location of what you plant. If your rows of green beans were on the backside of the garden last year, plant the beans on the front side this year.
After You Plant
Mulch around the plants. Mulch helps retain soil moisture and it can block weed growth. Plastic mulch, the black type specifically designed for gardens, is a good choice for around tomatoes and vining plants. Use leaves (like leaf mold) or newspaper around other vegetables.
Water as needed. Providing an exact watering schedule is difficult since the air temperature, type of soil, and what you have plant all calculate into the frequency of watering. Roughly speaking, water every five days if there is no significant rainfall (where it rains for at least an hour). Water deeply, down to at least 2 inches. During stretches of high heat and sun, the vegetables may need more frequent watering.
Test the soil moisture by pushing your index finger into the soil. If the soil is dry more than 2 inches down, then water the garden. If in doubt as to whether the soil is moist 2 inches down, use a plant moisture gauge. Use a permanent marker to highlight 2 inches up on the sensor of the moisture gauge. Insert the gauge into the ground up to that mark and read the results on the gauge.
Make a diagram of your garden, recording what you planted and when. A garden journal works well for this purpose. By tracking what and when you plant, and the results at harvest time, you will learn what works best for your soil, water and sun conditions.