Seed Starting Mix vs Potting Soil: Which to Use
Seed starting mix is sterile and light for germination. Potting soil has nutrients for established plants.
The Differences
| Factor | Seed Starting Mix | Potting Soil |
|---|---|---|
| Nutrients | None | Has fertilizer |
| Texture | Fine, light | Coarser |
| Sterility | Sterile | Not sterile |
| Best for | Germination, seedlings | Established plants |
When to Use Each
Seed Starting Mix:
- Germinating seeds
- Seedlings under 3 weeks
- Root cuttings
Potting Soil:
- Transplanted seedlings
- Established plants
- Container gardens
The Transition
When seedlings have 2-3 sets of true leaves (3-4 weeks), transplant into potting soil.
Common Questions
Can I use potting soil for seeds? Yes, but dilute 50% with perlite.
Can I use seed starting mix for adults? Yes, but fertilize weekly.
What about “seed starting potting mix”? Read the label. If it has fertilizer, it’s potting soil.
Can I make my own? 1 part peat, 1 part perlite, 1 part vermiculite.
Is coconut coir a substitute? Yes. Sustainable and effective.
Can I reuse seed starting mix? No. Pathogens persist.