Making your own fish emulsion is not only extremely easy, it is better than buying fish emulsion. This isn’t just because it is cheaper. To preserve fish emulsion, companies add preservatives (usually sulfur), not that fish emulsion ever smells really great. The purpose of these preservatives is to prevent microbial activity. So until the sulfur is sufficiently watered down, you are killing the very microbes you are trying to feed, and it isn’t clear exactly how much watering down will disperse the sulfur enough to be safe for your organic microbes. No matter how much water you add, the sulfur is in there somewhere. Making fish emulsion fresh ensures you are producing FOOD for soil microbes (which as a reminder, feed and protect your plants) instead of adding elements into your soil that don’t benefit the soil biology.
Go out and purchase yourself a nice fish for dinner. It doesn’t matter what kind. When you are finished filleting the fish, take the refuse (the skins, bones, fins, head, anything you don’t eat,)and cut it up into small parts. Put these parts into a blender with water and blend it all up until you have made it all into fish juice, no big parts left behind. And there you are, fish emulsion.
Depending on the type of fish you use, you will have anything from a cream colored to pink or reddish mixture.Put it out around the plants and water it in. The fish smell is very short-lived. The benefits are long-lasting. If you filter the mixture, you can make a foliar spray.
Fish emulsion is a great organic source of nitrogen and many other nutrients including a very nice array of trace minerals from the ocean. Avoid root vegetables, beans, or any crops that don’t want a lot of nitrogen, though a light application is beneficial. There is a fast-acting, water soluble element to fish emulsion that gives you immediate results. But there is also a longer-lasting element, which is the reaction from the microbes and biology in your soil. And you may also feel good that you have turned what is usually looked on as gross garbage waste, into liquid gold for your garden.