02/08/2026
Back in March, following Floret releasing their potting mix trial results, I decided to do another potting mix trial with some readily available additives.
This included various combinations of potting mix, compost, Revital Worm, Hamish’s secret mix, Dave’s Turbo, and the ‘Florets Winner’ mix of blood, bone and kelp meal.
I potted up some spare amaranthus seedlings into each mix, then sifted each mix and direct sowed some cornflower seeds into each one.
To be honest, the results were not quite what I expected,and a little bit contradictory in some cases! But overall, the addition of compost improved the growth of the seedlings, and the further addition of blood, bone and kelp gave the best growth (as found by Floret, so no surprises there!)
This mix was not the winner for sown seeds though - mixes containing compost and either Hamishs secret mix or Dave’s turbo did better than the one containing the blood/bone/kelp additive.
I love doing these little experiments, so will try some more this spring. I think I’ll use statice plants as they show the effects of poor nutrition quickly.
Let me know which potting mix is your go-to for potting up seedlings, and I’ll consider giving the most popular types a trial. Potting mix is pretty expensive so we want to know we’re using the one that’s best for our plants!
I’ll also trial some different concentrations of the bone/blood/kelp combo to see what works best. The kelp meal I used was pretty expensive, but I think I’ve found a cheaper source through a chicken feed place!
Putting my horticulture degree to good use???!