Hi, I am thrilled to see my seeds I sowed recently are quickly germinating and rapidly growing. However, they now seem to be getting spindly even though they've only started to grow for few days! I have had them in a propagator on my windowsill but perhaps it's too warm? How big do seedlings need to be before I can transplant them? Do I need to wait till they have made enough of a root system? They are not in really the tiny pots but in deep seed module trays or small pots.
The ones that seem to be growing faster than anything before are the zinnia and cosmos seeds. Last year it took at least 2 weeks to see them start to grow and slowly grew steadily, but this year they've both zoomed up in less than a week!! I do t want to loose them or end up with weak spindly plants. Should I be concerned or do something to slow them down? Should I put them out in the cold frame or is it too early?