I was so impressed with this test, here are the results.
I transplanted some small tropical milkweed seedlings on March 14th. I was testing using Miracle Gro versus Pro Mix BX and also testing putting Osmocote in the soil versus putting it on top of the soil. Here’s what the plants looked like on March 14th.
Below are what the plants look like on April 20th.
The plants on the left are the Pro Mix + 1/4 tsp Osmocote. It doesn’t seem to make much difference if the Osmocote is in the soil or on top of the soil – in the soil may be slightly better.
Pro Mix BX is hard to find, but I did find some at a local Home Depot.