Connecticut Garden Journal: Tips for choosing which soil mixes are best for your plants
It's getting to be indoor seed starting seed time. It's nice starting your own vegetables and flowers indoors from seed. You can grow many more plants for less cost and get to choose from a wider range of varieties. Even if you're not an indoor seed starter, at some point you're probably going to be buying potting soil. That's where soil mixes can become confusing.
There are seed starting or germinating mixes, transplant mixes, potting mixes, mixes with fertilizer, organic mixes, mixes for specialty plants.... it can be mind boggling. Let me try to help.
When starting seedlings indoors, get a seed starting mix. This is the usual peat-based mix, but it’s been more finely milled so the small seeds can germinate better. When transplanting seedlings into larger pots indoors, use an organic transplanting mix. This has more bulk in the mix and some compost, which helps keep the plant growing strong. For container plants in summer, a good potting mix should be fine.
If the plants are perennial, buy a product with compost, or even some bark, in the mix. That will help reduce potting soil compaction over time.
Peat moss is often the key ingredient in many mixes. There is concern about peat moss because the peat is mined, destroying the bogs. While bogs can be restored, it can take years to bring them back. An alternative is coir. Coir is a bi-product of the coconut industry. It's made from milled, coconut husks and is often found in many soil mixes. It absorbs and drains water better than peat moss and is a recycled product.