Bags and bails of soil have been stacked in greenhouse parking lots for months.
Each week the pile gets smaller as the bags are brought inside and used to start bedding-out- plants. Similar bags are starting to appear parking lots of large box stores.
This soil is often left out at night, unguarded and unattended.
While a few bags might disappear it doesn’t appear to be a big problem. These bags are bulky and cumbersome.
If the soil is wet it is very heavy.
The composition of potting soil is often a mystery as each company has its own source of raw materials as well as recipe for the finished produce.
Perlite, vermiculite and peatmoss are the basics of potting mixtures.
None of these materials contain a significant amount of nutrients.
It is rare to find top soil included in potting soil. Perlite and vermiculite are hard. They help water to flow through the soil insuring that small air-pockets are present.
Without the air pocket, roots would not be able to absorb moisture and nutrients.
Peatmoss has the capacity to hold enormous amounts of moisture for long periods of time. When peatmoss is not mixed with perlite or vermiculite it is either too wet or too dry.
Soil that is too wet is home to bacterial that causes the stem of plants to rot and the plant to die.
Dry peatmoss becomes hard and nearly impossible for water or roots to penetrate. Adding significant amounts of perlite and vermiculite solves the problem.
Soil bags at greenhouses contain a finely ground peatmoss mixed with perlite or vermiculite.
This fine material is light and allows seeds to germinate and push through the soil easily. The lack of soil and nutrients is not a problem as growers insure that the plants are fertilized regularly.
The same soil can be used in hanging baskets and planters but larger operations will use a coarser blend.
Once again regular fertilizer ensures that the plants thrive.
Plants will continue to grow and bloom all summer if they receive fertilizer and moisture on a regular basis.
When the fertilizer is allowed to become depleted the plant’s growth stagnates and becomes sickly.
Not all bags of soil contain peatmoss and perlite or vermiculite.
Some potting soil bags appear to be filled with a rough grade of peatmoss which includes sticks and some ground wood.
A soil such as this with poor drainage makes growing plants a real challenge.
At this time of year it is also possible to purchase bags of cow or sheep manure. Bagged manure should be well composted with little if any odour. Read the package carefully to see if the product has been sterilized and to see if a lit of nutrients is written on the package. Manure that has not been sterilized will contain some weed seeds. The number of seeds present is directly proportional to what the animals ate and how the product was composted.
Well-rotten manure can be added to planters to insure that there is a ready supply of nutrients all season.
It can also be used to top dress, spread over the top of flower and shrub beds. Nutrients from the manure will leach into the existing soil and the bulk of the material will improve soil structure.
Manure can also be worked into the soil where it will provide nutrients.
Compost will act similar to manure. Good quality compost is a welcome addition to every garden.
As all bagged soil is different, take time to read the packages.
If the store doesn’t have an open sample of the product on display ask staff to open a bag. Purchasing good soil will have a good impact on the garden.
Linda Tomlinson is a horticulturalist and educator living in Rocky Mountain House. You can contact her at firstname.lastname@example.org