What is compost? In gardening terms the word compost can be confusing as it can refer to garden compost you make yourself or for bags of peat compost you would purchase from a garden centre. In their essence they are indeed the same thing as both are made from broken down organic matter but there are a number of important differences:
Homemade garden compost
Homemade garden compost is made over a period of 2 to 12 months and is rich in nutrients and friendly bacteria. Garden compost is made by adding organic material like garden and kitchen plant waste to a heap or compost bin and allowing it to rot down into a dark and crumbly soil like substance. Adding homemade compost to your garden will improve soil structure by mixing organic matter through your soil but will also release nutrients which will help feed your plants.
Garden compost is an environment friendly gardening practice as it re-cycles green waste and uses it to grow new plants; it is a home version of the same cycle which built all the soils which cover the Earth.
Peat Compost is made over a period of thousands of years and while it is made up from (very old) organic matter it holds no nutrients and is completely sterile. Peat compost is only able to support plant life when nutrients are added to it as is the case with peat based multipurpose composts you buy in the shop. The nutrients added to peat based composts tend to be artificial and will only support plant growth for approximately 4 weeks.
While peat compost is good for improving soil structure it has no nutritional benefit to your plants. The harvesting of peat is becoming increasingly frowned upon as it destroys rare and unique plant and animal habitats and is not a renewable resource. Thankfully there are increasing amounts of peat free composts available on the market made form composted green wastes as well as other waste organic materials like coconut fibre.