Most people keep tomato seedlings inside until they are several inches tall at least. After that, the cotyledons are gone, and the seedlings are less fragile. But cotyledons are irrelevant once the main leaves start emerging. Cucurbits, with large seeds, tend to have big strong cotyledons. If the temperature outside is significantly lower than inside, the growth will be slower. Call it "stunted" if you like. It's normal.

Agree. Older seedlings with at least a couple sets of true leaves will usually recover from sun scorch and don't need their cotyledons any longer. Younger seedlings normally will not recover from sunburn or will be very slow to recover and develop (aka stunted).

Dave

Ok. Thank you. I guess the best I can do is just keep the soil moist and hope for best. They are just small roma tomato plants. They did start to slow down once I started putting them outside for a time. Im leaving them in the house now until I see they are doing much better. Then maybe trying taking them outside of increasing intervals of 30 minutes?

I would leave them outside but use something to give them shade. I think it'll be more stressful for them to yo-yo between inside and outside again.

One thing I like to do for small numbers of plants is use old window screens for shade. My process is:
- Day 1 put plants in completely shaded location
- Day 2 shade with 2 stacked window screens
- Day 4 shade with 1 window screen
- Day 5-6 remove window screen.

You could also do the same with some kind of shadecloth, or I've even used old curtain sheers I had lying around.

I include some flexibility for cloudy days.

That's not so bad. As long as the growing tip doesn't get so damaged that it dies, they should be OK and recover quite quickly. Tomatoes are kind of amazing at recovering from physical trauma, which makes up a bit for how disease prone they are. The basil might die, but basil is delicate when young.

Yea I was happy to see that new growth had formed this morning on the tomatos when I went to check on them this morning. The basil are still at a standstill, and I think might die like you say. Which is sortve unfortunate since I was hoping they could be companions plants with my tomatoes. Any tips about when I could/should fertilize?

I would wait to fertilize until new leaves get a little larger and more established. Sometimes, fertilization--or any change in growing conditions--when a plant is stressed by something else causes problems.

Start new basil, just in case. Even if the ones there survive, you'll be glad you succession planted when those plants get ready to bolt. I try to succession plant basil two or three weeks apart all season. I also find basil flowers beautiful, and the beneficials love them, so I like to have plants for eating co-existing with plants for the pollinators and such.

The basil may not be dead. It's normal for basil to seemingly do nothing for a while with only little tiny nubs of the first true leaves showing for seemingly forever. It's slow to start. But it's also more likely that the damage will kill them vs. the other more robust seedlings.

Ok. Thank you for the help. As mentioned this is my very first Garden and theres so much information out there its difficult to sort out what I should or shouldnt do. I was under the assumption planting basil about 18 inches from my tomato plant would help repel certain insects and things like this. I am pregnant expecting a baby at the end of the summer and handling or spraying any type of pesticides is not on my to do list at all. So I was trying to find natural ways to do this to help. If anything if problems develop then I guess Ill have someone else do the spraying lol. Thanks you all have been very helpful!

So true, Dan. Basil wants a lot of sun. I actually plant cilantro with my tomatoes because the shade may keep it from bolting so quickly, and when it does bolt, parasitoid wasps and hoverflies love the flowers.. If I had the space, I wouldn't co-plant at all, but my garden space is very limited.

Bettie, companion planting to REPEL pests never works. The myths persist because they're so attractive conceptually, but in reality, I've yet to find it makes any difference. Some myths, like planting marigolds next to your tomatoes, can actively backfire, since marigolds can attract mites, which are probably one of the worst kinds of infestations you can have on tomatoes and one that's hard to conquer without using more toxic options.

What DOES work is planting a lot of flowers throughout your garden to ATTRACT beneficial predators. Not necessarily companion planting right next to your edibles--that's not necessary--but nearby and throughout. Predators like lacewings, ladybugs, hoverflies, parasitoid wasps, etc. feed on pollen and nectar in their adult stages. As most are smaller insects, they especially like tiny, open flowers like Alyssum, flowering herbs, etc. These attract predators and encourage them to stick around and lay eggs, and their voracious larvae help significantly with pest control.

Thanks so much! I spread some wildflower seeds around my shed earlier. I wanna attract humming birds, mainly just because I like them haha. Would those work at all? Im probably going to plant some more flowers with my little girls (If i can convince them to stop picking them)

In my experience Scarlet Runner Beans attract hummingbirds.

I always liked to plant an occasional marigold among the vegetables because I found them attractive.

Yes, hummingbirds like long, tubular flowers, especially if they're red.