If you are starting your tomatoes from seeds, start them early enough that they will be about 8 inches tall with healthy, white roots for planting after the last frost. Recommended growing tips say to sow the seeds about 8 to 10 weeks before the last frost date. Repot as needed to keep them growing well. When planting them outside, make sure that you tie them loosely to stakes. Supporting their stems helps flower and fruit production, while also keeping tomatoes off the ground and away from many of the harmful pests.
Tomatoes are very susceptible to watering problems.
If you aren't regular with your watering, you can get various diseases and split tomatoes. While split tomatoes are usually perfectly safe to eat, they look unsightly. The cause of the splitting is when water is withheld and the fruit stops growing, and the outer skin begins to toughen up. When water is again available, the plant goes back into growth mode, and the skin must split in order to allow further growth. Tomatoes also want the water to go directly to the roots, so it is often advised to bury a bottomless coffee can next to the tomato and pour the water into the can rather than watering the plant itself.