Leachate friend or foe
Posted: Tue Jun 13, 2017 7:46 pm
Somebody in another thread ask about leachate. I felt it was a big enough subject to have its own thread. Please pass on your experience of using leachate and any information you have on it.
If you visit any worm/vermiculture site or read any book or magazine article related to the subject of vermiculture then you will see a great deal of discussion on leachate. It's a very hot topic at the moment. The opinions expressed are very far ranging, sometimes, very contradictory. Well known and well respected worm heads hold very different views on the usefulness and safety of using leachate. Some say it's a valuable plant food, others say use with caution and some say it's dangerous and should not be used directly on or near food crops.
Firstly what is leachate? To start with it's not worm tea nor compost tea nor casting tea these terms refer to a liquid which can be made from the compost/casting from your worm bin when they are mixed with water and re-oxygenated by stirring manually or with the help of a fish tank pump. Leachate is simply the liquid which got into your bin from from "wet" food or the environment i.e. rain or excess water being applied deliberately or by accident. This moisture perculates down through the trays collecting nutrients and microbes (some good and some bad) on its journey and you collect it via the tap in the sump. It is sometimes called "worm pee" but none of it comes directly from the worms. You would get the same substance if there were no worms in the bin. There is no disputing the fact that leachate can contain a lot of nutrients and goodness. However they can contain some nasties, the liquid which passes through the bin can be anaerobic and in this anaerobic soup bad bacteria and pathogens can breed, these baddies can harm and even kill plants and can result in health problems for us. The big problem is the fact that every batch of leaches is different even when taken from the same worm bin.
George Pilkington in his book "Composting with Worms, why waste your waste" states on page 61 "I have heard it called "worm tea" by so-call experts. He goes on to say pour the leaches on the compost heap.
Bentley of www.redwormcomposting.com says the jury is out on leachate.
Mary Appelhof in her book "Worms Eat My Garbage" acknowledges that some people use leachate to feed plants but makes no other comment.
Jeff Lowenfels and Wayne Lewis in their book "Teaming with Microbes" say leachate from compost adds little to the soil food web.
Worm bin manufactures and web sites selling worm bins claim leachate are a valuable liquid plant food.
Huy from TheLittleWormFarm.com states "Using leachate that leaks at the bottom isn't pointless but risky" he goes on to say "the long term wetness (which results in leachate) will potentially create an anaerobic environment where bad bacteria can breed"
In my opinion there is some good stuff in leachate but it needs treating with caution. I set some rules some time ago.
1) Avoid them, I manage my bin in a way which reduces the production of leachate.
2) If I get leachate, and I do sometimes, I check the smell, if they smell bad I dump them.
3) I aerate them before use. If it's a small amount this is a matter of putting them In a six pint milk bottle and giving them a good shake, larger amounts are put in a bucket and an air-stone connected to a aquarium pump is added to aerate for six hours.
4) dilute at least 12 to 1 with water (1 pint to a standard 1.5 gallon watering can) before use.
5) never water over plants.
6) use around flower and ornamentals, rarely use near edibles never near edibles which will be eaten within a month.
Hope that helps
Willy
My big concern about leachate is that it is taking goodness from the finished casting. There is only a finite amount of goodness in the food and bedding we put in the bin if we allow it to be "leached away" the finished casting will be poorer for it.
Willy
If you visit any worm/vermiculture site or read any book or magazine article related to the subject of vermiculture then you will see a great deal of discussion on leachate. It's a very hot topic at the moment. The opinions expressed are very far ranging, sometimes, very contradictory. Well known and well respected worm heads hold very different views on the usefulness and safety of using leachate. Some say it's a valuable plant food, others say use with caution and some say it's dangerous and should not be used directly on or near food crops.
Firstly what is leachate? To start with it's not worm tea nor compost tea nor casting tea these terms refer to a liquid which can be made from the compost/casting from your worm bin when they are mixed with water and re-oxygenated by stirring manually or with the help of a fish tank pump. Leachate is simply the liquid which got into your bin from from "wet" food or the environment i.e. rain or excess water being applied deliberately or by accident. This moisture perculates down through the trays collecting nutrients and microbes (some good and some bad) on its journey and you collect it via the tap in the sump. It is sometimes called "worm pee" but none of it comes directly from the worms. You would get the same substance if there were no worms in the bin. There is no disputing the fact that leachate can contain a lot of nutrients and goodness. However they can contain some nasties, the liquid which passes through the bin can be anaerobic and in this anaerobic soup bad bacteria and pathogens can breed, these baddies can harm and even kill plants and can result in health problems for us. The big problem is the fact that every batch of leaches is different even when taken from the same worm bin.
George Pilkington in his book "Composting with Worms, why waste your waste" states on page 61 "I have heard it called "worm tea" by so-call experts. He goes on to say pour the leaches on the compost heap.
Bentley of www.redwormcomposting.com says the jury is out on leachate.
Mary Appelhof in her book "Worms Eat My Garbage" acknowledges that some people use leachate to feed plants but makes no other comment.
Jeff Lowenfels and Wayne Lewis in their book "Teaming with Microbes" say leachate from compost adds little to the soil food web.
Worm bin manufactures and web sites selling worm bins claim leachate are a valuable liquid plant food.
Huy from TheLittleWormFarm.com states "Using leachate that leaks at the bottom isn't pointless but risky" he goes on to say "the long term wetness (which results in leachate) will potentially create an anaerobic environment where bad bacteria can breed"
In my opinion there is some good stuff in leachate but it needs treating with caution. I set some rules some time ago.
1) Avoid them, I manage my bin in a way which reduces the production of leachate.
2) If I get leachate, and I do sometimes, I check the smell, if they smell bad I dump them.
3) I aerate them before use. If it's a small amount this is a matter of putting them In a six pint milk bottle and giving them a good shake, larger amounts are put in a bucket and an air-stone connected to a aquarium pump is added to aerate for six hours.
4) dilute at least 12 to 1 with water (1 pint to a standard 1.5 gallon watering can) before use.
5) never water over plants.
6) use around flower and ornamentals, rarely use near edibles never near edibles which will be eaten within a month.
Hope that helps
Willy
My big concern about leachate is that it is taking goodness from the finished casting. There is only a finite amount of goodness in the food and bedding we put in the bin if we allow it to be "leached away" the finished casting will be poorer for it.
Willy