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?
I’m no expert, mind you. This year I did a coir/vermiculite/perlite blend for starting tomatoes. They sprouted fine but stalled—no true leaves for a couple weeks. After adding some fertilizer tea they’re growing again. Still not sure if they’re worth keeping but I’ll give them a shot.
Next time, I’ll try the starting blend with some soil added in. They just don’t get enough nutrition from just the starting mix.
I just use liquid food when I water. All my sprouts seem happy.
I use the same ingredient pool, and the catch to it is that you need to be giving the seeds some dilute liquid feed starting right after seeds sprout, since they get very little from the substrate itself.
You’ve got the right idea already; just saying this as a +1 nudge.