The End of Peat Pellets - Part II March 01 2016 1 Comment

seed-starting traysWell, it was a crazy summer/fall and I was swamped between working full-time and attending school full-time. I unfortunately was not able to do much in the garden. I was also not able to get around to providing a follow-up to my previous blog on starting seeds using 4” pots instead of peat pellets, and I do apologize for anyone that was waiting for the update! With school out of the way now, let me fill you in with some insights that I gained.

As stated in my previous blog, my wife and I decided to plant our vegetable garden seeds in 4” pots rather than peat pellets. We did this in hopes that we could save time by planting seeds into pots large enough that we would never have to repot them before transplanting them into the garden. It definitely saved us time from having to repot them, but the seedlings did not grow as vigorously as the previous year’s when we used the peat pellets. For comparison, in 2014 our pepper plants were already flowering indoors within 5 weeks of planting the seeds. In 2015, the pepper plants were only about 3 inches tall and nowhere near flowering by the time 6 weeks had passed.

Now, I do have to admit I didn’t conduct the experiment fairly because I also placed the seedlings outside much earlier in 2015. I began leaving the seedlings outside day and night on May 1st in hopes that the full sunlight would help them grow faster and stronger. If temperatures cooled and approached the mid-40’s I would bring them back indoors for the night. I’m afraid this may have been the detrimental part of the experiment especially since basil, tomatoes and peppers all love the heat.

After speaking about my experience with the owner of a local plant nursery, he said he has always heard that it is better to plant into a small container and then repot into a larger container. If a lot of room is provided in the container, the plants will focus their energy on root growth instead of growth above the ground. His suggestion is to always start seeds is small containers, such as seed-starting trays, and then repot them into larger pots as they become root-bound in the small containers. This definitely makes sense with how he explained it. But the growth rate was so drastic between the peat pellet method in 2014 and the 4” pot method in 2015 that I’m still sticking with my assumption that the temperature difference also played a large role in the grand scheme of things.

This year I am going to do another trial on container size, but I will still eliminate peat pellets. I’m not fond of the netting that you have to remove from the pellet in order to repot the seedling. This time I will plant some seeds in 4” pots, and other seeds in a seed-starting tray. Once the seedlings become root-bound in the tray, I will repot them into 4” pots. I will also keep all seedlings indoors and under lights until a week or so before I plant them in the ground. The last week will be spent hardening them off so that they will make a smoother transition to being outdoors 24/7.

I’ll post another update once seeds have been planted and everything is growing!
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.​