The End of Peat Pellets - Part I April 28 2015 1 Comment

basil seedlingsFor the past few years, my fiancé and I have used peat pellets when starting all of our garden seeds in the Spring. Since we start all the seeds on a heating mat, this has allowed us to easily germinate a fairly large number of seeds (sometimes more than 100) on just a few mats. Once they have sprouted and grown a bit we then repot the seedlings into square 4” pots to give them more room to grow before planting them in the garden outside. Although it works well, there is one problem with this method: it takes too much time!

Recently, we came across this article by Gayla Trail, and it caused us to rethink how we will plant this Spring. In the section titled, "My Favourite Seed Starting Containers," Trail states that it’s best to just start your seeds in a container large enough to hold them from seed all the way until you’re ready to plant them in the ground or a larger pot outdoors. This could be a huge time-saver, since repotting from peat pellets not only consists of making a hole in the potting mix, planting the seedling, and topping off with potting mix, but it also means cutting off the mesh netting around each and every peat pellet. Additionally, this new method may reduce the risk of harming the young seedlings’ roots while transplanting them from pellet to pot. Some seedlings grow very fast in the peat pellets, and by the time you get around to repotting them, their roots have grown through the mesh netting and may get torn off when removing the netting.

Last year we repotted 106 seedlings from peat pellets into 4” pots, so this alternate method would have saved an enormous amount of time! We have considered starting seeds in larger pots on numerous occasions, but various sources online have always deterred us with their warnings of damping off, which will cause your seedlings to perish. Peat pellets tend to dry out fairly quickly, so the chances of the peat staying too moist is slim. But when you start seeds directly in a larger pot, it will stay moist longer because there is a lot more soil to stay moist and little to no root system in the pot to soak it up.

We decided the best way to determine whether this method would work for us was just to try it out. After planting all our seeds two weeks ago, everything has sprouted (yay!) except for the habanero and cayenne peppers (boo!). Peppers like these seem to need a lot of warmth in order to germinate successfully so it may be that the soil volume in a 4" pot is too much for a heating mat to warm to the necessary temperature. We will leave the habanero and cayenne pots alone for now to see if the germination is just delayed, but will also start new ones in peat pellets on a heating mat to see if that method is successful.

Stay tuned for a follow-up or two on how things are progressing!

Chris Welch
A software developer by day and gardening enthusiast by late afternoon, Chris Welch enjoys all aspects of the gardening world from research and planning to planting and harvesting. He also loves the challenge of growing orchids, plumeria, and various other tropical plants in the very non-tropical state of Iowa. His most recent undertaking is a backyard native Iowa prairie that he hopes will increase native insect and wildlife populations and positively influence the ecological balance of his garden.​