| I've heard that it is necessary to empty out the existing soil from vegetable and annual flower containers and replace it with fresh potting soil each spring before re-planting. I have two very large planters on my rooftop garden and can't imagine doing this each year. What should I do? |
| Potting soil tends to deteriorate over time (the organic matter becomes depleted and the soil becomes compacted, the nutrients leach out, fertilizer salts can build up, pests or diseases can build up) and is best renewed annually for the overall health of the plants. With large planters it is sometimes adequate to refresh about a quarter to a third of the soil working from the top and being sure to add some good quality compost along with replacement soil mix. You may eventually need to replace it for best results, especially if you have problems with soil-borne diseases. |
