Fish emulsion is a soluble, liquid fertilizer that has been heat and acid processed from fish waste. Its typical N-P-K analysis is 5-2-2 and it adds needed micronutrients. Release time may be one to four months. Fish emulsion is one of many organic fertilizers derived from animal by-products and usually has a foul smell.

Organic fertilizers such as fish emulsion or blood meal can be used for container plants but may be available too slowly for actively growing plants. Additionally, the potting soil may develop a foul smell as it is difficult to leach the source of the smell through the pot. A better fertilizer choice for container plants is a controlled-release granular fertilizer that is mixed with the soil at planting time. Depending on the fertilizer requirements of the plant(s), it may also be necessary to use dilute-soluble fertilizers with every watering, or at full strength on a weekly or every two-week basis. Visit the Colorado State University Extension Web site at www.ext.colostate.edu, for Fact Sheet #7.238 "Container Gardens." You may access this information by clicking on Horticulture, then Fact Sheets and Basics.