Warmer temps = faster growth, if you had a temp of say 80F, or 85F, then the plants grow much much faster, otherwise, you have to wait longer.

The plants in my place are now cooler, but warmer since I took them inside recently.
But growth slows own a fair amount at 10C drop, about 2X as slow.
I suppose you could use a seedling heat mat, they are 20$ or so.


Regards,
Tom Barr