Water: Keep the soil moist like a sponge, not saturated. You can also mist the seedlings to keep them moist.
Air: Give the seedlings good air flow. Even running a small fan near them will keep air circulating and mimic the outdoors. In our research, we found that this can help prevent them from getting leggy.
Temperature: Seedlings grow best in cooler temps, like 60s to low 70s. If it gets too warm the seedlings may get leggy.
Thinning: Remember when we told you to plant multiple seeds per cell to ensure germination? If more than one seed germinated per cell, you need to thin them out. Only one seed can grow in a cell so they don’t compete for nutrients. Once you see the second set of leaves on your seedlings, choose the healthiest seedling to keep and snip the rest. Cut them at soil level and discard. Yes, it can be tough to decide which one to let go of! But don’t try to transplant each one into separate cells; they are too delicate, and you may end up destroying all of them in the process.
Repotting: The seedlings may outgrow their containers before they are ready to be transplanted into the garden. You will know this when the roots are taking over and the foliage is taking over its neighbor. Repot in a container twice the size of the original.
Hardening off: This is an important step before transplanting the seedlings into your garden. This process helps acclimate your seedlings to outdoor life without shocking them. Place them outdoors for a few hours each day and then bring them back in. Here’s a great guide to ensure the process is gradual and doesn’t kill your seedlings.
Now get your seeds and start growing! This should be a fun and experimental process, not to mention a great activity for kids. Hopefully we all have seed starting success and a longer growing period—keep an eye out for new Thursdays With Mother episodes to get our latest seed starting tips and updates.
Tell us: Are you starting seeds indoors this year? How’s it going?