Many of us gardeners fertilize based on the calendar, but is it necessary? Do you know if the nitrogen, phosphorus, or potassium levels are actually low in your soil? You can save yourself time and money by testing your soil with simple soil test kits. If you find that one of these main nutrients is low, then add just what’s needed. More is not better for any fertilizer. Too much of certain elements can result in damage to plants or soil organisms.
Want to try a feed and leave (controlled release) fertilizer? While they may seem to be a benefit to the gardener, they can be harmful to the soil. The water-soluble fertilizer is encased in a plastic type coating that allows the nutrients to slowly leach out. How quickly this happens depends on soil moisture and temperature. If the soil dries out, it can greatly reduce the amount of fertilizer released.
Multi-purpose products, often marketed as “All in One” or “3 in 1” contain a mixture of fertilizer, insecticide, and fungicide. Using this type of fertilizer product when there is no specific insect pest or disease present adds pesticides to the soil for no purpose, may negatively impact soil organisms, bees and other pollinators, and is much more expensive than single use products.
Before using any chemical in the garden, consider the impact of fertilizers on the environment and steps you can take to reduce them.