High quality soil is the foundation for growing success. Soil requirements for plants in containers are different from those grown in the ground or a raised bed garden. This is the thing worth spending extra money on if you were ever debating over spending money on a pretty pot or soil. Pick the soil. Below is an exploration of soil – its function and what a high quality soil looks like.
The Function of Soil:
- Acts as an anchor /support for plants
- Holds moisture & nutrients
- Provides air for roots to breathe
Components of good soil
- usually sterilized for weed prevention
- Has a light, airy density
- Is a mix of peat, composted bark, vermiculite, and possibly perlite
Peat moss – Canadian sourced peat moss is considered to be of excellent quality, its function is to retain moisture & nutrients.
Composed bark – serves as an anchor for roots, moisture & fertilizer retention, provides air spaces and organic matter.
Vermiculite is like a sponge – keeps the soil loose, keeps soil from compacting, aids in holding water & fertilizer.
Perlite– provides air spaces – keeps the soil from compacting, adds no nutrient value, using a large amount can lead to fluoride binding to it if using fluoride treated water – more of an issue for long term houseplant gardening than for container gardening – this is why not all mixes contain perlite.
- Mostly made purely of peat moss
- The problem with pure peat moss is — that when it gets dry out, it is extremely difficult to rehydrate & it actually repels water like a brick of concrete – so needs to be soaked –it may be able to return to its water retaining properties but this is challenging
Also, heavy soil doesn’t mean it’s good soil. It is either:
- very wet: very wet is likely an indicator that the soil is decomposing in the bag which can cause root rot (losing air space and then causing roots to rot)
- has a lot of sand: sand is a cheap filler – sand causes the soil to lose air spaces and that as well will cause root rot
Other notes on soil:
- There is a need to fertilize because potting soil doesn’t naturally possess a lot of nutrients
- Complex mixes with manure, garden soil, compost are for landscaping purposes, not container planting
- Good quality soil is most often bought at greenhouses and garden centers and it is always best to ask if the soil being sold in bags is the same as the one used in for their products
Sources: provenwinners.com, exploratorium.com, healthyurbanhabit.com