“If you plant flowers in a flowerpot, do you ever have to change out the soil, or does the soil never lose its nutrients? Question from Jessica of Phoenix City, Alabama
Answer: Potting soil must be changed or replenished every couple of years or so for many reasons beyond the fact that a plant may have outgrown its pot. Not only do plants remove fertilizer nutrients in the soil, but the soil components also break down and become more acidic over time. You can always add fresh fertilizer to the potting mix, but the changes caused by decomposition can only be fixed by adding fresh potting soil. Here are four important characteristics of fresh soil that are lost with age.
The Four Important Characteristics of Fresh Potting Soil
Fresh Black Gold® potting soil has:
- Lots of air pockets to facilitate good drainage and aeration for healthy root growth. (As potting soil ages, and its organic matter breaks down, these air pockets are lost.)
- Better water-holding characteristics. (As potting soil ages, water is less available to plant roots.)
- A more neutral pH. (As potting soil ages, it becomes more acidic, which many plants do not like.)
- A better ability to distribute nutrients to plants. (As potting soil ages, plant roots have a harder time accessing fertilizer in the soil.)
After two to three years, replenish your pots with fresh potting soil. When I add new potting soil to my containers, I take the old mix and add it to my garden beds as an amendment. That way, nothing is wasted.
Black Gold Horticulturist