Plants grow to about 2" and stop...

[Echobelly]

I live on the Gulf Coast of Florida. Tried my first grow last summer. All 5 seeds sprouted, planted them in pots of Miracle gro seed starter mix outside in full sun. Each plant grew to about 2-3" in a few days and stopped. They leafed out, one even budded (I think), and then just stopped, didn't die, just stopped growing, like it was a super mini dwarf variety. I figured the middle of the summer wasn't the best time to grow here, too hot and humid. Planted 5 more sprouted seeds a month ago in an organic potting soil, perfect growing weather, same thing, 2-3" and stop. I tested the PH, it's between 6 and 7. I water when the soil is dry (sometimes daily, the clay pots dry out fast). The first crop was Indica, these are Sativa, which I understand will grow better in my climate. Any ideas what's wrong? It's a lot of work (and money) for a couple pipefulls (very happy with the quality of the pot, though).

 

[Bluey]

Full midday sun in summer is too much light & probably too much heat. Keep them in the shade or inside beside a window for starters.

If using soiless medium you have to give nutes of around 0.3 or 0.4 EC from the start. Keep humidity high, maybe 75%

 

[User420111]

Second this comment. When I start growing seedlings indoors the light manufacturer recommends keeping the LED's at 40% power. Little seedlings don't need a ton of bright light. Let them develop their roots first, giving them time to send that big tap root ten or twelve inches down into the soil. Then slowly start turning up the light as the plants grow their first few set of nodes. If outdoors use shade or tents.

 

[Echobelly]

Thanks! I'll move the pots to a shadier spot!