Using Putrid Worm Tea

Here is a question from Debra:

Good AFternoon,
I am relatively new to the vericomposting craft. I just love the
ideal of making use of all that we are blessed with. My Grandmother
used to tell me “waste not…want not”.
Anyway, I have a vericompost bin set up (approximately 5 months now).
I have been harvesting the liquid; keeping it in gallon jugs until
Spring. I live in the Pacific Northwest and we have some pretty
extreme temps during the winter. I’ve noticed a very strong smell
from the liquid with a thin film on top. I am assuming that this
indicates anarobic (the bad bacteria) growth. Can I use this liquid
with the bad smell; should I try to airate it with air stones before
use? I don’t want to harm any of my precious plants come spring time.
But I also do not want to discard something that I could make usable.
Thank you for your website and your words of wisdom. We, in the
field, appreciate all you do!

Hi Debra,
Interesting question. In all honesty, I definitely wouldn’t put worm bin leachate in bottles and just let it sit for months – the potential for it becoming a putrid mess is pretty high!
I hate to recommend getting rid of ANY potentially useful resource though (remember – even ‘wastes’ are just misplaced resources), so I certainly wouldn’t tell you to just chuck it.

Bare minimum, you really should dilute it and start aerating it well before trying to use it. Use your nose as a quality tester – as long as it has any bad odor you definitely don’t want to use it. Even once it is fairly odorless, I’d still recommend using it with caution – maybe pour some in an area of your garden you aren’t all that concerned about. Or simply pour it on some weeds – who knows, maybe you’ve invented the ultimate weed killer and don’t even know it! (just for fun, maybe you could try out the pure, unaerated stuff and see what happens)

Once it looks as though it’s not going to harm your plants, you can probably get a little more bold with your use of it.

Hope this helps!

Written by Bentley on February 25th, 2009 with 2 comments.
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Does Vermicompost Go Bad?

Here is an interesting email from Crissy:

Quick question about the use of vermicompost – does it go
bad, and if so, how do I know not to use it?

I harvested my worm bin for the first time back in October, which was
just before the rain started here. The compost was pretty wet, but
for the most part smelled like rich soil. I’d planned to let it dry
outside a bit, then store it in bags or jars and give it to my
gardening friends, but I misjudged the weather. It’s been sitting
outside in a big, fairly shallow plastic flower pot, loosely covered
with a tarp ever since.

I’ve decided that I want to give container gardening a shot this
year, and want to amend some old potting soil with the vermicompost.
I just want to make sure that it’s still okay to use before I get
everything planted.

Hi Crissy – that’s actually a great question!
I’ll start by saying “it depends”. What it depends on is how stabilized your vermicompost is. By definition, vermicompost is a ‘humus-like’ end product that results from the stabilization of organic wastes (thanks to the joint effort of worms and microbes). Humus is a highly stable material – very resistant to further breakdown. As an analogy, consider peat moss – or potting soil (which usually contains a lot of peat moss). If you soak brand new peat moss and let it sit indefinitely, it will never go ‘bad’ or decompose much further than it already has. This is the same idea with really good quality composts.

If there is still a fair amount of partially decomposed waste materials left in your vermicompost, there is a decent chance that these could rot further – and if this occurs under anaerobic conditions, you could end up with a material that is considered ‘bad’. In other words, it is basically the anaerobic breakdown of unstabilized organic wastes that results in nasty smells and the foul nature of ‘rotten’ materials. Believe it or not, if you ground up fresh chicken meat (an example of a material that would be really nasty if rotten) and mixed it with a LOT of peat moss or some other bedding material (along with some mature compost for good measure) and provided the mixture with a LOT of oxygen, it would compost just like anything else.

Farm animal mortality composting is actually quite common. It is next to impossible to eliminate ALL anaerobic microsites in a mixture, so there could still be some odors – but its amazing what you can do when you add enough bedding and provide enough oxygen.

Anyway – I’m getting sidetracked here.

Good vermicompost should keep for quite some time (sometimes years) – and it really only loses its potency, rather than going ‘bad’. If it is sitting outside, exposed to the elements, the quality can degrade quite quickly – but if covered up, it should be totally fine for at least multiple months.

It certainly won’t hurt to use it, either way (again assuming it is good quality stuff to begin with). Just mix it up and take a whiff. If it smells rotten, mix it some more then put it somewhere dry to sit (on top of multiple layers of corrugated cardboard might help to draw out excess moisture). It should eventually become aerobic (with the rich, earthy smell of good humus), and useful as a soil amendment.

Hope this helps!

Written by Bentley on February 25th, 2009 with no comments.
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