Seed Starting: A Few Things I've Learned

I am certainly no expert on seed starting, but over the last year and a half I have learned a lot! Yes, that is code for “killed lots of baby plants.” Last year my results were pretty dismal. I had maybe 6 Bells of Ireland that survived long enough for me to plant them outside, a handful of snapdragons, and really not much else. Oh, tomatoes. I did have some tomatoes that made it as well.

Snapdragon seedlings, last year. They germinated great, but only a few survived long enough to be planted out into the garden!

Snapdragon seedlings, last year. They germinated great, but only a few survived long enough to be planted out into the garden!

Nothing like setting the bar at ground level, eh?! Perhaps because of all that failure, I am thrilled with any progress that my plants make this year!

So, if you’re even more of a beginner than I am, let me share with you a few of the things I have learned that have helped my success rate go up. Some of it’s having the right equipment and some is giving them a chance to get used to changes.

  1. Use a heat mat. They’re fairly inexpensive, and most seedlings will germinate much faster on a heat mat. If you can’t afford even a small one, try the top of your refrigerator, or someplace equally warm.

  2. You also need humidity domes of some kind. Plastic wrap works if you’re using cell trays or pots. In any case, get something! Without it, the seed casings will tend to stick to your first set of leaves. If those casings don’t come off, your seedling will die sooner rather than later, because it prevents the first set of leaves from unfolding and photosynthesizing.

    This is not like baby chicks that have to peck their own way out of their shells to survive. In a humid environment, the seed casings slip right off of their own accord, usually. Without one, they don't. Simple as that.

    The bigger seeds you can usually split with a fingernail or tweezers and gently pull them off. The tiny ones, though, like snapdragons? Forget about it! If they don’t come off on their own, that little plant is finished before it has even begun.

  3. Last piece of equipment advice: get a grow light or two. Your baby plants need at least 14-16 hours bright light per day. They’re not going to get that with a windowsill. (Plus, windows tend to be cold, which also inhibits growth!) The plants will do best if you keep the lights just 1-2” above their little heads. Move the lights up as needed.

  4. Before you plant them outside, you’ve got to harden them off. This means gradually get them used to living conditions out in the Real World—you know, where there’s wind, bright direct sunshine, and weather. If you stick them directly out into the garden, the shock will kill them. It’s an abrupt and awful end to weeks of work. Trust me on this one!

    So, give them some time to get used to it all. A week to ten days is the usual. Start them off with just an hour or two of being outside in a sheltered, shady location. Gradually introduce them to stronger sunshine and longer hours.

    I’ll tell you what—it’s the transporting them in and out that kills me with this one! In and out and in and out. If they are COOL FLOWERS, don’t worry as much about cold night temps killing them off, but do go slower on introducing them to full sun. For your warm weather lovers, do the opposite: take them in at night if it’s going to be cold, and maybe go a touch faster at exposing them to the heat and full sun. Keep them well watered outside, too.


What tips do you have for me? I have killed my fair share of seedlings already this spring, so please know I feel your seed starting pain!

New York asters—in the actual flowerbed out front!! You can see they are still quite small, but they seem to be doing well out there so far! These little guys are supposed to grow up to 3 feet tall and bloom in the fall. I’ll keep you posted!

New York asters—in the actual flowerbed out front!! You can see they are still quite small, but they seem to be doing well out there so far! These little guys are supposed to grow up to 3 feet tall and bloom in the fall. I’ll keep you posted!

I am pretty proud of my successes so far, though! To date: sweet peas planted out into the garden—still alive, though they don’t seem to have grown much yet. Also, New York asters planted into my front flowerbeds just this past week. They actually do seem to have grown since getting in the ground—yeah! I’ve got pansies on the back deck looking pretty good, and snapdragons seedlings—still small, but still growing—that I’m hardening off to plant into the garden in the next week. Tomatoes and pepper seedlings are growing like crazy! Need to get them potted up and started hardening off, as well. Project for next week!

Have you had any success with seed starting this year?