I Tested 5 Seed Starting Mixes. Here’s the Ranking.
I tested 5 seed starting mixes with the same seeds. Here’s the germination rate, growth speed, and cost of each.
The Test
10 radish seeds per mix. Same pot size. Same water. Same light. 14 days.
The Results
| Mix | Germination | Height (day 14) | Cost |
|---|---|---|---|
| Brand A (peat-based) | 9/10 | 3.2 in | $8 |
| Brand B (coir-based) | 8/10 | 2.8 in | $10 |
| Brand C (organic) | 9/10 | 3.0 in | $12 |
| DIY (peat+perlite+vermiculite) | 10/10 | 3.5 in | $4 |
| Generic potting soil | 6/10 | 2.1 in | $5 |
The Winner
DIY mix. Best germination, best growth, lowest cost.
Recipe: 1 part peat moss, 1 part perlite, 1 part vermiculite.
What I Learned
- Potting soil is too heavy for seed starting.
- DIY mix is easy and cheap.
- Brand doesn’t matter much — ingredients do.