In South Louisiana, plump, juicy tomatoes are a summertime staple in much of the local fare. Though they are a common addition to gardens in that region, tomatoes can be difficult to grown there--the scorching sun and soaring humidity make for less-than-ideal conditions. It's important to keep tomatoes in this area well-watered because the heat can cause irregular flower development and low fruit production.
Choose tomato cultivars that are recommended for South Louisiana. Determinate types include Olympic, Mountain Delight and Celebrity. Indeterminate types include Pink Girl, Monte Carlo and Better Boy. Tomatoes that are designed to have heat-set genetic makeup, such as Solar Set and Sunchaser, also do well in the area. If you aren't sure what type of seedlings to purchase, ask the experts at your local garden center.
Prepare the soil before planting. Use a shovel or hand tiller to loosen the top 8 to 10 inches of soil in the garden bed. Sprinkle a 1- to 2-inch layer of compost over the bed and mix it in to the aerated soil. This will give the plants the nutrient boost they need to combat the heat.
Plant deep. Dig holes for the seedlings that are about 6 inches deep. The extra soil will keep the roots cool and protect them from the sun. The roots will also be able to draw more moisture from the dirt if they're planted a bit deeper. Space the holes 18 to 24 inches apart.
Place the seedlings in their holes, then add about a cup of water-soluble fertilizer (prepared according to the instructions on the packaging) to each hole before filling it in with soil.
Cover the garden bed with a several-inches-thick layer of light-colored mulch. The mulch will lock in the moisture and also repel the worst of the sun's rays.
Water the tomato plants daily, first thing in the morning. The plants will need about 2 quarts of water each before the first harvest and 2 to 4 quarts of water after that. Watering the plants in the early morning allows them to absorb as much moisture as possible before the hottest part of the day.
Sprinkle about 1 tbsp. of general-purpose granular fertilizer around the base of each plant when the first green tomatoes have reached about a quarter of their mature size. Repeat this treatment every four weeks to keep the tomatoes healthy and well-fed.