When to pick out seedlings from communal tray


Dear Toronto Master Gardeners,
I have started several flower species indoors under grow lights. The tiny Heliotrope ‘Marine Lemoine strain’ seeds were sown in a flat tray. I searched online but cannot find any info for when to pick them out and transplant into individual pots. They were started March 11, ~3 ½ weeks ago. They are very slow growing and I’m unsure when to transplant. I’d very much appreciate your input.
Thank you,
Patricia D


Thanks for visiting our Toronto Master Gardeners ‘ASK a Master Gardener’ page! Congratulations with your seed-growing experiment.

Seedlings can be pricked out (or transplanted into single pots) when they show their first set of true leaves. In practical terms, this means the second set of leaves visible – the first set being the cotyledons or embryonic leaves in the seed. The “true leaves” get their name because they begin to look like the mature leaves of a plant.

Holding onto a leaf or cotyledon, and never the delicate stem, you can gently pry the roots from the growing medium using a small spoon, using this to move the seedling into the prepared pot.

You’ll find more detailed information on seed starting on our printable Master Gardener growing guide:


Other reliable sources of information are linked below – with the first link showing an example of the difference between true leaves and cotyledons:



Good luck with your seedlings and enjoy your fragrant heliotrope.