By seed starting mix I mean any seed starting medium, e.g. rock wool, peat moss, coco coir, etc.
In January, YouTube creator Soil and Margaritas / Garden Life published a video of her latest experiment around potting mixes (that’s right, potting mixes) for starting seeds indoors.
Her rationale for starting her seeds in potting mix is when she uses seed starting mix, she eventually transplants them to potting mix anyway. She acknowledges that not all potting mix is suitable for starting seeds - for example, one of the specific products she tested was very chunky, which significantly hindered those seeds’ germination and growth. That said, she claims that some potting mixes are “fluffy” enough to work well enough for starting seeds.
She tests Chinese noodle beans, sunflowers, and zinnias w/ six products:
- Vermont Compost Company Feed the Soil Fort Vee All Purpose Compost Based Potting Mix (the one she used in 2025)
- Miracle Gro Potting Mix
- Promix Premium Moisture Potting Mix
- Fox Farm Ocean Forest Potting Soil
- Black Gold Natural & Organic Potting Mix Plus Fertilizer
- Espoma Organic Potting Mix
Not accounting for price, personally I’d rank the performance as follows:
- Vermont Compost Company Feed the Soil Fort Vee All Purpose Compost Based Potting Mix (the one she used in 2025)
- Miracle Gro Potting Mix
- Fox Farm Ocean Forest Potting Soil
- Promix Premium Moisture Potting Mix
- Black Gold Natural & Organic Potting Mix Plus Fertilizer
- Espoma Organic Potting Mix (performed the worst, although she acknowledges in her video that this particular product is very chunky and this company has a seed starting mix on the market)
What do people of c/gardening use for starting their seeds? What are your thoughts on this test?
Sorry you about made me spit out my coffee.
Beans, zinnas and sunflowers are some of the less picky species for substrate. Both sunflowers and beens have large seeds and enough stored energy to supply the plant to the second true leaf. Zinnia’s have extremely durable and high germinating seeds. For testing seedling mixes they are a poor choice. Mainly because they will do well in most things.
There is no “correct” seedling mix for everything. Every species has its own optimal growth medium based upon its unique needs.
What works well for tomatoes is too fine for squash. What works for cantaloupes holds too much water for watermelons. Then there is the whole slow germinating flower seeds. That’s a mess of different preferences.
I see your point. In the case of the YT video I linked in the OP, the tester considered variety of crops as a factor, but perhaps you’re right that those particular crops do not represent a diverse enough set of “pickiness” among seeds. Toward the end of her video, she does acknowledge that what makes sense for her may not make sense for all of her viewers growing different crops in different climates, and she encourages her viewers to run their own tests. Thanks for chiming in on that.