By Alex Robles
So the seeds you set out to germinate finally crack and now you have to put them in some soil. Do you believe the marketing and buy a sprouting soil mix or do you make your own, but which recipe should you follow? Well you’re in luck because today I’m going back to church so I can keep preaching about my love for worm castings and let me tell you that love runs deep. Since I grow in dirt, in containers there are very few things I lean on more than a great bag of castings to help me keep my garden healthy during all stages of growth. In the past I’ve rambled on about the different ways I use it, from top dressing to making tea. But today I’m going to go over how I use it to make a sprouting soil mix.
How It Happened
After I soak the seeds in a cup of water for a couple (two) of days, they usually start showing signs of a tap root (plumule). This is when I’ll move them into some kind of spouting cup filled with sprouting soil mix and wait. As long as I keep the soil moist (not too dry or too saturated because both conditions will kill a seedling), the lights on and the temps between 70F-85F. I should have great looking seedlings sprout up in a few days.
The first pair of leaves that will be pushed out are called cotyledons and will have rounded ends. Those two little leaves kick start the photosynthesis process so the plant can start making energy. A few days later the next pair of leaves will have the serrated edge look that is characteristic to cannabis plants. The seedling stage lasts about three weeks, I judge it this way. Once the seedlings has three sets of cannabis leaves it’s no longer a seedling.
I wait about a week too ten days before I plant the whole sprouting cup into a Solo cup with the same soil mix. I don’t want to start them off in too big of a pot because that’s an easy way to overwater/underwater a young seedling.
Sprouting Soil Recipe
I use an equal amount of worm castings and soil to make my sprouting mix. I stay away from soils that have time release fertilizer pellets( Miracle-Gro) because they’ll be too hot (loaded with too many nutrients) and will burn the seedling before it gets started. I use an organic soil mix called “Recipe 420” believe it or not. I also don’t use straight worm castings because it’s so fine it compact which makes watering and air circulation in the root zone difficult.
4 day old seedlings (The Cool One)
Growers Note: The worm castings that I link to below aren’t the best ones I’ve ever used. But they are pretty good and one of the better ones that seem to always be available on Amazon. I figure we all don’t have a quality nursery or grow store nearby, but almost all of us can get to Amazon.
That’s it, that’s all I’ve got today so go forth and sprout some seeds.
Grow, Learn, Teach