Harvesting

This is an area I’m still looking for better techniques…. Here is what I have so far…

When is it time to harvest?

Here is a photo of newpaper from my bin a few weeks after I added it to the bin:

Some worm castings are accumulating and the newspaper is breaking down but there is still a long way to go.

But as time goes the worm castings start to accumulate more and more, especially at the bottom of the box. I mix it up a bit to help bury the remaining newspaper.

The soil is really ready to harvest when all the newspaper has disappeared. It isn’t smelly. The worms will be concentrated where you feed them last.

There is still some stubborn vegetable mater in the soil, but the bin is mostly worm castings.

“Lateral Harvesting”

Quick description:

Worms will hide from light to I basically spend five minutes at a timing scrapping the soil off the top of the mound, checking for worms that I might of scooped up, and then leaving it for a while for the exposed worms to dig down deeper. I don’t remove hundred percent of the soil this way, but I can take out most of it.

Detailed Description of Andrew’s Method:

You can figure our your own specific technique, but I thought it worthwhile to describe more in detail how I do this.

When you see that the entire top of the box is pure castings, with no newspaper visible it is time to think about harvesting. I don’t necessarily harvest as soon as the newspaper is gone – I may just add more newspaper. However when I feel that the box is getting too heavy I remove some soil.

I find it most efficient to work with my bare hands. I avoid the buried compost so it’s not too “gross”. You can use rubber gloves or a spoon if you don’t like getting dirty hands.

Look at your box and figure out which side was fed more recently, this side will be the “active side”. The other side will be the “harvesting side”. You probably won’t do a complete 50/50 division, the harvest side might be closer to 35% of the box.

Scrap your fingers on the “harvest side”, pulling away the soil to make a pile of worm castings on the active side. I’ll call this the soil pile. Keep going until you start to unearth any remaining vegetable matter. Just do a quick job, you don’t have to do a complete separation. But avoid putting any vegetable matter in your soil pile.

Scoop all the remaining material out of the “harvest side” and put it in a different pile on the “active side” side. There will probably be some uncomposted material in this pile but if you scoop it out with a huge handful it won’t be too yucky.

So at this point the harvest side is empty and you have two piles – one that is mostly soil and the other that contains soil and uncomposted material.

Next dump the soil pile back into the harvest side.

Also drag your fingers through the compost to scrap more soil from the top of the active side into the harvest soil. Avoid any areas of uncomposted material. You will still find some stubborn vegetable material which you can avoid putting in the harvest side. Don’t worry if some worms are going in the harvest pile.

On the “active side” rearrange things to make sure that the raw composting material is buried again. Then leave the box for a few days or a week.

When you come back, e.g. for another feeding, you can pull more soil from the active side into the harvest side. Never feed on the harvest side.

Keep repeating as long as you like, maybe two or three weeks, and once you have a decent amount of soil accumulated in the harvest side you can take it out of the box. I usually do this bit by bit over the course of a day that I’m going to be hanging around the apartment. Have a bucket to take the soil. Do this in bright light, e.g. the sunshine on your balcony.

Open the lid and do a final effort to take some soil from the active side. You might want to also loosen up the soil on the harvest side. Wait a while for the worms to hide themselves deeper in the soil.

Now scoop the top layer of soil into your bucket, it is easier to do this with bare hands. There should be hardly any worms at all. Do a quick check for worms and remaining chunks of vegetable matter. Loosen the soil that remains. Wait a while longer.

Keep going until the harvest soil is mostly gone. It will probably take 3 or 4 steps, but each only takes a minute or two. When the remaining soil in the harvest pile gets too shallow it will have lots of worms in it. Make a pile of the remaining soil and you will be able to remove a bit more soil. What will remain will be a handful or so of soil that is full of worms and you can consider yourself done.

Now that the harvest is complete you can put some food in the harvest side bury it with some fresh newspaper.

Dump and Sort Harvesting

This is a more direct approach – you dump the bin onto a tarp, shine bright lights to drive the worms down, and skim the soil off the top.

Worm Cocoons

There are also many, many worm cocoons in my soil. These are the equivalent of an “egg” for worms, but each contains several worms. The worm population will regulate itself so the babies won’t hatch it there are already many worms in the bin. From a healthy bin you’ll be able to donate a lot of worms to get other people started because all these eggs cocoons are waiting to help repopulate.

I try to pick them out when I see them during my harvesting but its impossible to preserve all of them.