I got my greenhouse the end of last year, so still very new

[Guest]

.. It is not heated. This is radish and turnips, planted 12/30 (zone 6). Are they super slow growing, or am I just being impatient?

[Larry]

No heat, no grow

[Clare]

It's too early. They are cool weather crops, but that just means don't sow them in the heat of summer. They will do better sown in March, and catch up with any earlier sowings.

[Merrill]

Look online for simple lists of minimum germination temps. I found one that says turnips need 85°! I start seeds indoors and take them out once the first set of true leaves is well developed.