What do I do with my balsam seedlings, now in a planter?

Question

I guess I should have planted them in the soil by now, but the weather is so hot.

Answer 1

You may want to wait for cooler weather, depending upon how tall the seedlings have grown. Here's an article that may help:
https://www.gardeningknowhow.com/ornamental/flowers/balsam/balsam-plant-information.htm