Can Plant Food Go Bad?

Liquid Plant Food

• Liquid plant food formulation is very stable and may contain major plant elements like nitrogen and phosphorus as well as micronutrients such as iron and zinc. The container should always be closed tightly and stored at room temperature at all times. However, if exposed to alternating high and low temperatures in summer and winter respectively, the product may crystallize, rendering it unusable.

Granular Fertilizers

• Granular fertilizers should always be stored in airtight containers; otherwise, nitrogen in the fertilizer may be lost as ammonia. This would lead to loss of the guaranteed percentage of nutrients stamped on the product container. If granular fertilizers absorb moisture, they clump into hard "cakes," rendering them unusable as directed by the manufacturer.

Organic Fertilizers

• All organic fertilizers, whether liquid or granular, originate from living matter and, therefore, degrade with time. Examples include blood meal, fish meal and kelp. They should be stored in a dry location. Organic fertilizers should not be stacked on each other while in storage.