Overwintering Soil Amendments*


As I was assessing my collection of winter ice melters, and salt, I noticed I have some fertilizer left.
I have 25 litres of compost, as well as 5 litres of promix and a couple of litres of potting mix. Will these be usable in the spring/summer? I don’t have any indoor plants at this time. Can I use them in a west Toronto garden now?


How lovely to have compost and promix and potting mix available for use next spring. We would suggest that you store these items in their original bags or containers to know the content and analysis of the products next season. Anything granular should be stored in a dry location. Granular products absorb moisture from the air, causing them to cake like cement. An excellent way to store opened products is to place the bags in large containers, such as five-gallon buckets, and cover with tight-sealing lids.

Low winter temperatures will slow or temporarily stop the composting process:. As air temperatures warm up in the spring, microbial activity will resume.

Yet even when the temperature drops, microbes responsible for the breakdown of organic matter can remain active in the compost pile, according the Texas AgriLife Extension Service. The centre of the pile can be warm and actively composting because of heat generated by bacteria, but the outer layers of your pile are at the mercy of the daily highs and lows.

It may be better to use the products in the spring rather than now.  At the moment plants are dormant and covered with snow.  They will benefit most from compost in the spring.