“I would like to find out how long one can store the liquid fertilizer that is collected from the worm castings. When I want to make use of the residue to spray for pests then how do I use it? (At what concentration). Is there any other literature that I can use to read up on this matter?” ~ Melissa Daniels
After writing about how to use the leachate not long ago, it is timely to talk about the storage of this leachate.
There is no specific time you can store leachate, but I will recommend storing for no longer than 1 month unless it is treated by bubbling and a bit of stirring. Leachate is definitely a storable product, much more so than worm tea. Once treated, the leachate can be stored for a year or probably 2.
Leachate contains mostly soluble minerals and nutrients dissolved from passing through the worm compost. It may contain some anaerobic micro-organisms, and when bottled theses microbes can grow and produce toxins harmful to your plants.
By bubbling (with a fish tank aerator for example) and stirring it for approx an hour, the process can make sure that no anaerobic bacteria is present before bottling.
The reason why leachates can be stored longer than worm tea is the lack of microbes it contains, since it does not contain much sugar and food for microbes to grow on. But a lack of it doesn’t mean it doesn’t contain any, just that they won’t grow prolifically and won’t consume oxygen quickly.
In the first few weeks of bottling, there will be some production of gases, and you may see your bottle expand a little.
Release this gas periodically until the microbes become less active.
Before using your leachate, use your nose and smell it to see if it is putrid. If it smells horrible, then the best is not to use it. But even if it doesn’t smell rotten, I will use leachate with care. Test it on some small plants first, and if it is okay use it in the rest of the garden.