“Do I have to change the soil mix in my outdoor containers every year?” –Question from Jay of Burlington, Canada
Answer: What are you growing and where? In general, the organic matter in soilless growing mix breaks down over the years. Not only does it loose structure, causing it to hold less air and moisture, but it loses nutrients, so additional fertilization is always required. Potting mix has a useful lifespan of about 1 to 2 years, before it needs to be amended, added to, or replaced. This is particularly the case with outdoor container plantings.