I used a 5 gallon bucket and made the mix using "parts" measured with an old drink pitcher.
I mixed up:
3 parts peat
2 parts sand
2 parts compost
1 parts soil
1/2 cup gypsum
1/2 cup all purpose organic fertilizer (I used eco scraps "rose food")
Using a 5 gallon bucket was great for mixing, but not so great for creating the blocks. It would be better in a flat - wide container like a kitty litter box.
But - in all, it was easy to mix up and make the blocks - as long as you are okay with "less than perfect." If you are a perfectionist, it will take you longer to make them perfect and it might be a frustrating endeavor.
As of this writing, I have transferred one set of blocks to the garden - the sunflowers - and they transplanted like a breeze! There was no fighting the soil out of the container, no breaking apart, no mess. I just dug a hole, put the block inside, and covered it up. It was so nice and easy.
I imagine this will provide a lot of extra care for the hard to transplant seedlings like squash and melons.
However....all was not a rosy day in the sun. The blocks dried out like crazy. I had to put greenhouse covers over my containers. Since I only had 2, one of my containers dried out considerably and was delayed in germinating by over 2 weeks.
Germination was great for some plants and spotty for others. I always have trouble germinating melons, squash, and ground cherries. There was no change in the blocks. They took the same long time as usual. I also had some damping off - as I normally do in my smaller seedlings (like basil.) You must spritz the top in the beginning and that was tough on those seedlings. Once they grow roots (and they will!) you can water from the bottom and everything works so much better.
Some of my blocks that took forever to germinate started to break apart. I tried to put them back together but they were not solid as before - of course, these were melon blocks which are already a difficult crop for me.
Hardening off was really easy - I just take the whole tray out and leave them outside. I used to carry individual pots. Also, there is no garbage to throw out! No tags, no pots, no nothing. I will reuse the jiffy pots (I got these in the recycle rack for free at Lowes) and never have any plant packaging waste.
I used the 2" blocks for every seedling - even little bitty basils and ground cherries. They worked great. Maybe smaller blocks would have been better for the small plants, but the big ones do work.
I will definitely do it again next year - but will be prepared with covers for all the plants until they germinate.
This article may contain ads or affiliate links.