I like to use natural fertilizers as much as possible, which is why I compost everything from coffee filters to eggshells, kitchen scraps and, yes, dead squirrels. Once the microbes do their work on my numerous composting bins/bales/piles, there is nutrient rich gold left behind.
I’ve also been a fan of fish emulsion. This stuff is pretty much as nasty as it sounds in concentrated form. Its putrefied fish leftovers, liquified and strained into a thick soupy solution. Its concentrated, and when mixed with water according to the instructions, is pretty great stuff.
While its not nearly as gross smelling as the word “putrefied” makes it sound, it does have a bit of a fishy smell even if the maker says its been deodorized. But a wise organic gardener knows the dominant smell of fish emulsion is fertile food for his plants, and that’s good. After I apply this stuff to my plants, I can smell the fishiness for a while. It might bother some, but it doesn’t bother me. You can’t smell it unless you are actually near by.
The NPK ratio of most fish emulsion is 5-1-1 or 5-2-2. Its that number 5 that is pretty great. That’s a good dose of water-soluble Nitrogen that gets plants growing really well, right away. Since it is water soluble, the nutrients are available immediately to the plants. The Phosphorus and Potassium seem low, but fish emulsion is packed with many micro-nutrients and goodies that get the soil critters fed and breeding so the micro-fauna can do their job underground. Healthy soil means you have to feed the microbes, not just the plants. Here is a good breakdown on the benefits of fish emulsion, along with some info on making your own. The very simple basics of fertilizers can be studied here.
When and How to Use
I use fish emulsion early in the growing season, before my plants start fruiting. The higher nitrogen really gets the plant going well and seems to be a good solution for young seedlings. I’ve used it for 10 years and only purchased two quarts of the stuff, so it lasts. In fact, I should probably get some fresh stock since it tends to thicken.
Shake it up well, measure out a couple to three tablespoons per gallon of water, and mix well. That’s all. Because the nitrogen is water soluble and immediately available to plants, it can be applied as a foliar fertilizer as well as to the soil. I use it as both and just scoop out a half pint at a time with an old yogurt container and toss it under and on my plants. Any leftovers get tossed on other plants or go on the compost. Apply every two or three weeks during the growing stages, but stop using the fish emulsion when flowers and fruit are eminent. High Nitrogen encourages leafy growth and plant structure, when fruit production begins, other fertilizers are better. More on those at a later date.
Here’s a good video on how to use fish emulsion.
And here’s one on how to make your own.