Seed Starting - Dense Planting Method
If you've read my seed starting guide, you know that I use the dense planting method. Here, I'll go into a little more depth on this advanced seed starting technique. If you are just beginning on your seed starting journey, start with the first part of my guide on equipment.
Dense Planting Method
If you are starting a lot of plants, either for yourself or to give away to others, you can try a dense planting method. I have also seen it referred to as the overseeding method. It entails planting several seeds of one variety in each cell of your seed starting tray, and then splitting them into their own pots that they will grow in until being planted out.
I have done up to 30 seeds per cell with success. You have to be a little quicker with uppotting though since their roots will quickly become crowded.
One thing to keep in mind is that the tray space you start out with will multiply greatly when you split them. So, you may start out with one tray of densely sown seeds, and end up with five, seven, or ten trays filled with the larger pots with one plant per container. It can quickly become overwhelming, especially if you don’t have enough grow lights or south facing windows to keep them in after up-potting them.
I believe I first learned of this method a decade+ ago by watching a Craig Lehoullier youtube video, where he demonstrated how he starts tomatoes. I start a lot of seeds for my annual plant sale, so this is what I do every year. It also works for varieties that don't mind being crowded, and can be split when transplanting, like onion, and as long as they are not too densely planted, I've been able to do this with basil as well.
Here is a video I made on planting onions with the dense planting method.
If you are prepared for all of the work to split them, and have the space for more plants than you expected, give it a try!
Just for fun... a conversation between my husband and me
Nicole: “Why do I always start so many plants?! Splitting them is so much woorkkkk! And I’ve run out of pots!”
Husband: “I don’t know… I try to tell you every year. Just cull the ones you don't need.”
Nicole: “*Gasp* No! Each plant has the potential to have dozens of pounds of produce, and someone else can use them!”
Husband: *...ok, have fun with that*
Later….
Nicole: *complaining that my back aches and I’ve been separating and up-potting seedlings and writing out tags for hours and hours*
Husband: *Refrains from saying I told you…*
My husband and I have some variation on this conversation every. single. year. I somehow get amnesia and forget just how much work it is. Oh, I’ll just plant a few extras...no big deal, right? The problem with planting 2-3 seeds because you want to get one plant, is that you usually get 100% germination. Multiply that by starting sometimes 30+ varieties of tomatoes, and 20+ varieties of peppers, and it snowballs. Not to mention I start extras to give away, sell, or trade. Every year since 2016 I have done plant sales (sometimes hundreds, sometimes just a few dozen). Don’t get me wrong, I LOVE starting and caring for seedlings. But there is always a day (or a week) that I am hard at work separating plants into larger pots and it feels like I’m never going to get through it all. Worth it though.