Aged Manure – Ultimate Food For Red Worms

Manure Worm
A manure Red Worm as compared to one of my normal Reds, raised on food scraps and cardboard

Back in April I wrote about the ‘wild’ Red Wigglers I got from the manure pile sitting at a friend’s horse stable. Looking back, and remembering the size of those worms (comparable to the ones in my own systems), I’d have to say they must have been quite young.

I had the opportunity to visit my friend’s horse stable this past weekend, and of course I headed straight for the manure pile as soon as I arrived. With a little bit of digging I quickly found a lot of seriously jumbo Red Worms – and they certainly lived up to their ‘wiggler’ name too!

Needless to say, I was pretty excited, and I made sure to take a bunch of the material (with worms) home with me.

These Reds are actually fairly close in size to some of the Euros I have, although certainly not as fat. It’s funny – I’ve recently been amazed by the size of the Red Worms in my food waste trenches out in the garden. They have been among the biggest worms I’ve personally grown – yet they are still not as big as these manure worms (we’ll see how big they are by the end of the season though – likely still some growth left in them).

I suspect that based on their size and their vigorous wiggling action, these Reds (an my trench worms for that matter) would be excellent bait worms or live food for larger fish, reptiles, birds etc.

Manure Worms
These Red Worms are long, but not as fat as European or Canadian Nightcrawlers.

Finding these big worms the other day certainly served as a reminder of the fact that manure is pretty well the ultimate food for Red Wigglers (and likely other composting worms as well). As I’ve mentioned before, my very first experience with Red Worms (at the ripe old age of 14) involved finding unbelievable quantities of them in a huge pile of old manure out behind a horse barn.

If anyone reading this happens to have horses or other livestock (or can get a hold of large amounts of manure) I would highly recommend creating your own aged manure vermicomposting heap. If the manure isn’t already mixed with straw or some other type of bedding I would highly recommend that you mix some in. It will help to aerate the heap and will shift the Carbon/Nitrogen ratio more in favour of the worms. If the pile is big enough, you likely won’t even need to worry about cooler winter temperatures since it will stay above freezing (maybe even a lot warmer) in the middle of the pile. Once the manure no longer has a strong manure smell it will probably be ok to add the worms. Just to be safe, you may want to add a fair amount of neutral bedding material – such as moistened straw, newspaper etc, or even the entire contents of a worm bin – on the surface of the heap to provide the worms with a safe zone if the manure still isn’t quite ready to inhabit.

What’s interesting is that another friend of mine (who I actually buy worms from sometimes) has loads of Red Worms in his manure piles yet they are quite small in comparison to the ones I found, and seem to also look a fair bit different – this would be totally normal if they came from different habitats, but is a little puzzling given the fact that they live in a very similar material. This has me even more convinced that either there are in fact subspecies of Eisenia fetida, or one of the two are Eisenia andrei (a very close relative). I guess we’ll see how they both look as they grow in my systems – if they end up looking exactly the same over time then my theory will likely get tossed out the window.

Given the great nutritional value of manure and the nice uniform consistency (in comparison to food waste) – not to mention the lack of issues with fungus gnats and fruit flies – I think I’m going to start feeding my worms more of this material. I think manure and cardboard combined would provide the ultimate in breeding a growth potential.

Anyway – I’ll keep you posted!

[tags]red worms, red wigglers, manure worms, eisenia fetida, european nightcrawlers, eisenia hortensis, canadian nightcrawlers, lumbricus terrestris[/tags]

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  1. Bentley,
    Great to hear it. I actually started a trench in the card that I’ve been putting the alpaca manure into with the hopes of getting some worms established in it. I wasn’t really thinking and should have added some cardboard to it as the wheelbarrows were being dumped in.
    I’m currently down to two worm bins. The 4 gallon bucket which has a very high density of worms in and is working nicely and the 55 gallon drum with a very low density of worms in but hopefully increasing. I do move some over on occasion but I don’t want to deplete my well established bin too much. Both are getting house scraps as well as aged alpaca manure.


    • Susan
    • August 25, 2008

    With the short time between generations and the multiple locations of worm species around the world, you’re bound to get subspecies. As you probably already know, one of the most common forms of speciation (coming up with a new species) in nature is the bottle-neck. A few isolated individuals breed to become a large population. Any minor changes in the few original members will be magnified in the offspring. I’d say shipping small amounts of worms hither and yon, or even taking a handful out of an established bin to start a new bin is a great way to duplicate a bottle neck. (Each island in the Galapagos islands has a different species of giant tortoise – they’ve been genetically isolated for millennia.)

    I’m not suggesting we have new species, but we’ve sure set up the right environment for that to happen over the next few thousand years. Do you know anyone doing molecular genetics? I’ll bet we’ve already started a great experiment for them!

    • vermiman
    • August 26, 2008


    I raise rabbits. The manure that I let set and age draw Black Soldier Flies.

    • Jeff
    • August 27, 2008

    I haven’t seen this breed of worm in my manure piles
    The first pic with the 2 worms in your hand, the bigger worm looks to me like a European N/C, I am sure it isn’t, but it looks like one to me.


    • Bentley
    • August 27, 2008

    Allen – great to hear from you. I bet alpaca manure must make for great worm food. I suggest adding cardboard because it is a great worm habitat and seems to stimulate cocoon production.

    Susan – interesting thoughts. Thanks for sharing. I do know of a research team at the University of Guelph doing ‘barcoding’ taxonomy for as many species as they can. I should see how they’ve made out with the earthworms.

    Vermiman – Using manure outdoors can definitely attract an assortment of other critters not found in food waste systems. Now that my fruit fly and fungus gnats are pretty well gone I am now dealing with a variety of biting fly which seems to breed readily in manure! Sheesh, I can’t seem to catch a break!

    Jeff – if you saw these up close you likely wouldn’t see as much of a resemblance with Euros. They are very reddish (I found Euros to be more of a brownish) and not as fat and round. We’ll see what they look like after living in my systems for a few months.

  2. Hi Bentley,

    My Euro’s are Red, exactly the same color as Red Wigglers. I’ve recently heard that worms can turn different shades based on what they are fed. Would probably be an interesting experiment.

    • Bentley
    • August 29, 2008

    Very interesting, Jerry – thanks for sharing that. I’m quite sure there aren’t Euros (multiple reasons apart from the colour), but that does indeed sound like and interesting experiment!

    • Debbie
    • August 30, 2008

    Just a Warning!
    If you are adding worms to your manure pile, or adding manure to your worm bin, please be aware if your livestock (cows, horses) have been ‘de-wormed’ or been given anything to kill their parasitic worms inside them. I think many farmers do this. If so, it is possible to accidentally kill off whole populations of worms within days. If it is well aged manure it is less of an issue, but I’m not sure how long is enough time. Hmm, maybe I should go and find my source for this information.


    • Jeff
    • August 30, 2008

    Hi guys
    just adding a little about worm colors

    The Euros are not exactly the same colour as Reds, There is some differences, worms can turn different shades based on what they are fed, but the Euros are not exactly the same colour but very close.


    • Bentley
    • September 1, 2008

    I’m sure that like Red Worms, Euros can look different based on a variety of different factors – where they live, what they are eating etc etc.
    The biggest difference between them is definitely the size.

    Debbie – thanks for mentioning that. Definitely something to keep in mind. I’m pretty sure aging or hot composting will eliminate most of the danger. It’s certainly not a bad idea to be careful with fresh manures though (for this and various other reasons).


    • Patricia
    • September 1, 2008

    Great topic. I use only manure and some cardboard. Although I have more worms than I can count, I would like very much to improve the size of my worms. Hard to separate the worms when they are so small. What would be a good thing to add that would be a buffet for them? Dryer lint maybe?

    • Bentley
    • September 5, 2008

    Hi Patricia,
    I am really surprised to hear that your worms are not getting bigger in manure – it is pretty well the ultimate material for optimal worm nutrition. How fresh is the manure you are using? If it has been allowed to age for too long it can lose a lot of its nutritional value. Dry conditions can also result in smaller worms – how is the moisture content of your manure?

    Some strains of Red Worms just seem to be naturally small, even when fully grown. Interestingly enough I do know of a population of small Red Worms that live in manure heaps (owned by a worm farming friend).

    How big are yours and how big do you want them?
    It may just be a matter of perspective as well.


    • Patricia
    • September 9, 2008

    Bentley, I read and reread your post and I think all of your responses apply. Our weather has been in the 90’s consistently and it is hard trying to keep them moist. When I had checked my aging manure it was wet on top but dry and gray underneath. I do see alot of different sizes and shades of red when I am harvesting. what I might do is run a soaker hose across the top of my shade frame and just let it drip down until this weather breaks a bit. My manure is aged for a few days in the stalls and then put into a bin right away. Just for grins, when do you think manure starts to lose it nutritional value? Also, do worms respond to water conditions in regard to nitrates and e.coli? Or are they immune to that stuff. TIA Patricia

    • Bentley
    • September 9, 2008

    Hi Patricia,
    That is really odd that manure could be wet on top yet dry down below – generally, the only way this could happen is if you are hot composting (since water vapor would leave the hot zones down below). Or perhaps you mean that even with watering the manure, the water isn’t getting down very deep?

    Letting your manure age for only a few days certainly won’t get rid of any nutritional value – this only happens over the course of months as the manure gradually turns to compost.

    Not sure I follow re: the nitrates and e. coli. The vermicomposting process generally promotes nitrification – meaning the end material generally has more nitrate than the starting material (where organic N and ammonium would be dominant). There has also been quite a bit of research to show that vermicomposting can kill pathogens like E. coli.
    Not sure if any of that is helpful, but I figured it was worth mentioning.


    • Patricia
    • September 10, 2008

    Bentley, that is what i meant on the water. Even after I water sometimes the water doesn’t get all the way down to the bottom so that is why I was thinking drip water system. In regards to the water we were recently told that our well water had too many nitrates which can affect the animals and e.coli. Was curious if that would also affect the worms? I always appreciate your comments. TIA

    • Patricia
    • September 10, 2008

    Oh sorry forgot to add this. My bins are concrete block and less than 16 inches deep. Nitrates can affect animals with intestional ailments and poor coat condition. If I eventually get a water storage tank I will be filtering out the nitrates and e.coli. Should I expect any changes? I do understand that might be a difficult guestion to answer. TIA

    • Bentley
    • September 10, 2008

    Ok, so in the future you will have water completely free of nitrates and E.coli that you’ll be adding to the manure? If so, this certainly won’t be an issue. Not sure I’m following re: the link between nitrates and E. coli though – you said “our well water had too many nitrates which can affect animals and E. coli”.
    I don’t imagine the nitrates would harm the worms, but you never know – I know that worm growth in their own castings is stunted, so perhaps this is partially due to the nitrate concentrations that increase as a result of vermicomposting. I am more inclined to believe that it is due to the poor nutritional value of the material.

    • Patricia
    • September 17, 2008

    Sounds good. Maybe I am just overthinking this whole thing. Worms are much easier and less maintainence than cattle and horses. LOL

    • Nick
    • December 8, 2008

    Hi Bentley,

    What exactly constitutes “Aged Manure”?
    I have no access to a horse stable.
    Would manure bought at a nursery or Home Depot (bagged), be considered aged? Will it be suitable for feeding my red wigglers?

    Love your blog!
    Keep up the great work.


    • Bentley
    • December 8, 2008

    Hi Nick – the manure you are talking about would likely be considered VERY well aged – that stuff is basically fully stabilized compost. It might be ok to use in a worm bed, but I’m not sure how much food value would be left. It is worth trying out though.

    When I think of aged manure I think of material that still kinda looks like manure, but no longer has the pungent manure smell.

    • Patricia
    • December 9, 2008

    Nick, I used to work for Home Depot and they DID NOT recommend that product for alot of things. They carried it because it was asked for but it hardly sold. Not knowing where you live I would say save your money. JMO

  3. To All,

    As far as composting with “Indian Blue Worms” they eat almost anything, meat, cheese, even pet feces- whatevers.. I do not add seeds, avacado shells common sense stuff. I’ve had my worms for many years now been composting with my pets feces and they are doing awesome. Aging the manure, I would recommend a 5 gal bucket, drill holes for air ventilation add stredded newspaper, mix in cow feed add to worm bin a week later- let it rot. Tips: Add stredded newspaper to outdoor bins when attracting too much flies, this adds carbon especially need when composting with manure. Always bury manure/food good! Works for my worms!

    • scott
    • February 21, 2009

    I recently found a source for composted manure to use in my, as of yet to be built, raised garden beds. My thought was to possibly use some of it for dressing my e.f. worm bin started in october. Would medicated cattle manure… if it is medicated… I haven’t asked yet, still be a concern in latter stages for either the garden or a worm bin?

    keep up the good work….

    • Bentley
    • February 24, 2009

    Hi Scott,
    ‘Worming’ medication should break down in manure as it ages or if it is composted. My suggestion is to test it out on a small scale if you are concerned, and see how the worms respond.

    • Lee in Iowa
    • April 10, 2009

    Hey, Nick! You might not “have access to” horse manure, but you can get access to it. Look in the Yellow Pages and try and find a nearby riding stable. Polite approaches to ask for manure have always worked for me, no matter where I lived. Oftentimes the stable manager will direct you to the oldest pile, for manure you can immediately put on the garden, and to the newer piles which you can use for wormfood. Think about it. Every single horse poops 100 pounds a day! They NEED you to come with buckets and bins and shovel up some of their goodies.

    • Candin
    • September 15, 2009

    I just picked up some real aged horse manure at a ranch. It was in a huge pile and me being concerned with the daily worm medication they give them, wanted to ensure the meds had been well leached out. Not as much concerned with nutriion as I am with wiping out my flock. I will test it on a smal scale and perhaps go back for the “newer” manure?

    They provide daily deworming meds to their horses here in Texas from what I understand.


    • Candin
    • September 15, 2009

    I forgot to add this. If the well aged horse manure is of no nutritional value. It certainly is cheaper then Peat (and renewable) and is great bedding material. Peat adds no nutritional value and is pretty expensive also. Comments?


    • Herbie
    • December 12, 2010

    RABBIT MANURE?? I would be interested in hearing from anyone who has used rabbit manure extensively for worm food. How long have you let it age before adding to or making a new bed? What has been combined with it to make the worm bed or make it an acceptable food? Does most of the urine need to be removed before using? Thanks!

  4. I feed my rabbits, rabbits pellets and orchard grass, I then throw that mix in old truck bed liners with worms every 3-4 months, worms love it. I wanted to add cardboard and news paper but their safety as non toxic I could not confirm. All I got was made in china? I have lots of oak trees around and allot of leaves, Oak leaf mulch is right up there with rabbit manure so I added that to the bin, The oak leaves turbo charged my worms! The other thing is never use chlorinated water on your worms or garden! Check out my site

    • Alfonso
    • April 7, 2013

    I have red worms of 20 cms ( 7.87 Inches ).

    I put 5 cocoons in a 5 ga bucket and 50 cocoons in other bucket of the same size, and fed worms with kitchen foodwaste blended with watter, so there is always a kind of mud. from the 5 cocoons I got 30 worms of 7.8 inches and in the other bucket I got a lot like 600 but only 4 inches long,
    In other bin I put other 5 cocoons and fed them only with carton that I blended with water it was like a mud of carton. I got 16 worms but also 7.8 inches long and very fat

    So I think size is related to the space, and a very wet enviroment,

    • June 12, 2013

    As a youngster, my friend and I used to fish on the Missouri River just south and slightly east of Sioux City, Iowa. At that time the city had one of the largest cattle, hog, and sheep stockyards in the nation. My friend introduced me to “manure worms” what you refer to as red wigglers. We would go to the stockyards, find large heaps of cow or sheep manure, or better yet a shaded area where water used to clean out the pens drained on to or damp not wet manure. Joe my friend and I had all the red wigglers we could handle, in fact one spring my brother and I dug up a large galvanized wash tub of them. They varied in size, usually those found in damp shaded dirt or manure piles that were moist, were 3-4 times bigger than those we found in manure piles.

    As for fish bait they are great. They secrete a yellow juice and boy do the fish go it: catfish, carp, sauger, and just about any other species. We used them for pan fish and they went nuts.


    • Chris
    • November 2, 2015

    Is there a danger of just throwing in a fresh pile of cow manure right in for feed? I found a pile of cow manure under a tree. It wasn’t very wet or too dry. I threw it in my bin and my worms went crazy! They haven’t even really touched the other foods I’ve given them. Is it bad to feed them only manure?

    • Rob
    • January 4, 2017

    Curious how your wild red worm bins turned out? We have horses and our piles are full of red worms. I would love to save time and money by using these to populate my bins on a commercial level but am afraid that they will be the wrong species. Thoughts?

    • Bentley
    • January 10, 2017

    Hey Rob – I’ve been using “wild” Red Worms for years now. If your heaps are absolutely loaded with Red Worms there is a VERY good chance you have the correct kind of worms. The other “Red Worms” – Lumbricus rubellus tend to occur in lower numbers, and usually closer to the bottom of outdoor beds (or at least where temps are cooler). It is rare to see them in anywhere near the same densities as Eisenia sp worms. Be sure to check out this post for photos of both of these worms:

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