Having just given away a skosh of tomato seedlings, I’ma write up some tomato knowledge for posterity.
Tomatoes need all the sunshine you can give them. They also love water, but hate to be soggy. Seedlings, in small pots, might need to be watered twice a day, but not so much they are sodden.
The small hairs on the tomato stem all have the ability to become roots, so plant your seedlings deep (do not cover leaves) for a nice strong root system.
Large pots, planting beds, straight into the ground…they love it all. Tomatoes are basically weeds with benefits.
As they grow, you’ll see small leaves sprout from the “elbows” of branches.
These are called “suckers,” and are basically nutrient hogs. Pinch them off and the plant will be less wild and should produce more/better fruit.
Tomatoes are classified “indeterminate” or “determinate.” Determinate means they will reach a certain height and stay there. Indeterminate means they will grow forever and take over your existence and future. Just plan accordingly when you are deciding where to put them, and don’t be afraid to prune!
Support is essential. I’m a fan of tomato cages, available at any garden center, but you can use stakes, stakes with twine, old ladders, tall people…whatever is handy and stable.
Airflow between plants is essential…both in reducing the spread of disease and pests, and allowing them to just plain dry out between rains. Always water at the base of the plant, avoid wetting the leaves so as not to invite fungus/mold.
As they grow, tomatoes want to be FED. I’m a fan of the generic Miracle Grow type stuff, as it contains a decent balance between the stuff to make leaves/stems (nitrogen) and the stuff to make fruit (phosphorus). Tomatoes ADORE calcium (and need it especially during fruiting), so save up all your eggshells, wash them, crush them, and sprinkle around the base of the plants. I also highly recommend a Blossom End Rot spray for spraying the actual fruit.
Hornworms are the big enemy. The Five Spotted Hawk Moth lays eggs in the soil under tomatoes (and peppers, and and and), which hatch into this bastard…
And this bastard will strip your tomato plants to the stems overnight. Mulch under the plants will help a bit, but your best bet is just vigilance. Check the plants every day. If you see chewing, find the chewer and squash his ass. If you’re not into squishing 5″ long freaks of nature, you can also use Bacillus thuringiensis, a natural bacteria that literally makes a meal of caterpillars. (Seriously, they turn into brown bags of goo then explode.) Sadly it affects ALL caterpillars so the hunt-and-squish method is generally better. NOTE: Apparently shining a blacklight on them in the dark will make them glow, making the shitbirds easier to see. (Blacklight flashlights are cheap, who knew??) Another video example.
Here’s a good guide on all the other things that can affect tomatoes. Whiteflies and leaf miners are the only other things I really see here in Florida.
It is possible to keep the plants going during the rainy season. Just be sure to harvest anything that’s ripe or near-ripe before a big rain, as the plant will take up all that water and split the fruit, as well as make it near-tasteless.