Mint & Lemon Balm seedlings growing very slowly?

[Sweets777]

I started lemon balm and a few mint varieties from seed indoors exactly one month ago, seedlings were mostly germinated and sprouting from the ground within 10-14 days. At this point, one month from planting seed, I was hoping to have already up-potted and in the process of hardening off but I'm still waiting given their small size and slow growth.

Almost all seedlings have their first set of leaves, but few have more than that. I'd like to pot-up into standard indoor potting soil to provide the needed nutrients (currently in peat moss) but I want to make sure it's not too early where handling these small seedlings would cause damage/stunt growth.

Have a look a the pictures and let me know your thoughts - do these seem to be slow growing given that they're at one month, and would it be too early to pot up given that most have a single set of true leaves?

Seed starting setup:

- red/blue LED grow lights, 14-16 hrs/day
- watering when surface appears dry; every 2-3 days
- peat moss seed starting medium
- fan circulating air in the room
- first ~2 weeks (heating mat at 70f, humidity dome)

 

[Chuck]

Your plants are not leggy so that means there is enough light. You are watering frequently and the seedlings look ok. So, that leaves nutrition. Peat moss has little if any nutrional value. I would feed them 1/2 strength organic liquid fertilizer every 3rd watering. Mints like a soil with very little if any acid, so don't repot into peat moss.

 

[Sweets777]

The fertilizer is a good call, as the sprouts with true leaves probably need some supplemental nutrition. I fertilized them a while back and they're looking good!