Growing cosmo seedlings inside
I’m growing cosmo flowers inside my house while the frost is still ongoing. I have them all in 3 inch pots, one seedling per pot. How long should they stay in these pots before all going into a bigger pot? Also, which size pot fits these flowers best and how many seedlings can fit into it? I don’t want to add too many flowers because I’ve heard they get tangled in each others roots. Thank you in advance!
When you start to see roots sticking out the sides of the peat pots, it is time to pot them up. Cosmos don't like a lot of handling so it is ideal if they can be hardened off and put in the garden at this time. Do not fertilize cosmos as this results in excessive green growth and fewer flowers. Spacing depends on which cosmos you have as some are bigger than others. They need lots of sun and will grow sideways to get it if needed. If your seed packet says to plant 18" apart in the ground, don't go more than 2 in a 12" diameter container. https://www.gardeningknowhow.com/ornamental/flowers/cosmos/growing-cosmos-in-pots.htm