Early to mid-April; depends on the soil temps.
For tomatoes and peppers, you can leave a couple rot on the plant and let them germinate in the spring.

Thank you! I'll do some experimenting next year in April with my extra seeds. I'll also leave some cherry tomatoes and little peppers in the ground to rot and see what happens there.

We planted eggplant seeds March 1 this past year, they did fine but grew pretty slowly until April. No frost after planting.

Thanks alligatorob! I do have some extra seeds that I'll start planting on March 1st. This will be a great learning experiment for me. :)

Tomatoes are usually started from seed around Christmas in and outdoors depending on the weather; in pots. Transplants are set out later with DIY wire cages later used as supports. The cages can be covered with plastic if or when we have cooler weather or hard winds. Peppers are usually started about Feb also in pots for earlier starts. Never had any problems with eggplant they love hot weather and long days.

Here in South Alabama, we need to plant indoors by January at least so we can have decent-sized plants in the ground as soon as average last frost date (late Feb or early March) ... or even earlier, with protection. They need the cool weather to grow and produce before the hot, humid nights kick in. HOWEVER, we have fall tomatoes that volunteered from the summer 'maters, and some bush cherry volunteers in the greenhouse for winter.

I don't direct seed them, but occasionally one comes up from a tomato or pepper that I tossed. The tomato is usually Texas Wild, and this year the pepper is Pequin, which is very hot. When they volunteer, they are usually too late to produce anything and die in the summer heat. I had a Texas Wild volunteer this fall, but we've already had a couple of nights of freezes, and it was only a few inches tall and froze along with the tomatoes I planted a couple of months ago.

I'm starting on eggplant, for the first time. I have qty. 8 that have sprouted and are about 2" high. I've read that they don't like cooler weather, and apparently prefer 70s-80s. Do you know how they handle 90+ degree temps?

I found they love heat and long days.

I have baby tomotes plants coming up everywhere, even in the grass. They are about 6 inches tall, they reseed themselves every year. I do not know when they do this, but it must have been at least a month ago. Since we did not have a freeze, all my tomotes are still producing, especially the cherry tomatoes. Does anyone know if I need to trim them back, they are getting leggy and covering the ground. Barbra