Here are some great questions from Scott – very much related to some of the concepts I touched upon in my recent ‘Restaurant Vermicomposting‘ post.
We live in Utah and we have hot summers and cold winters. Our home
sits on a lot that is a little over one acre. On our property we have
four grow boxes and a large conventional vegetable garden. The grow
boxes have a “soil” that is a mixture of city compost (tree composted
using sewage), steer manure, vermiculite, peat moss, and potting soil.
The soil in the yard is a light yellowish-tan clay. There are no
worms and it is quite alkaline. To get things to grow in the soil I
have been told by a landscaper that you can amend the soil with sulfur
to lower the pH. We added compost from a compost tumbler and city
compost to the vegetable garden. The garden is growing fairly well.
I have a compost tumbler and have been wanting to get into
vermicomposting as well. I am curious about a few things. Could red
wiggler worms be put in my grow box to help improve my “soil?” How
about in my vegetable garden? What vermicompost system works best for
a family of nine that does not require a lot of maintenance? How do
you protect the worms in very hot and very cold seasons? Could the
worms be added to the yard as well? We are planning on landscaping
the yard and adding city compost as topsoil. what do you think?
Sounds like you have a really interesting set-up there.
While it is a pretty standard recommendation to not add composting worms to conventional garden soil, it certainly can be done if the necessary requirements of the worms are provided. In a nutshell, you simply need to provide a supply of rich organic matter if you want Red Worms (and others) to stay put.
As I’ve discovered this summer, there are a variety of ‘systems’ you can build in or on top of your soil for what is essentially in situ vermicomposting. The method that has been working incredibly well for me thus far is the vermicomposting trench – from what I can tell, this is a fantastic way to keep a healthy population of Red Worms in your vegetable garden, and to provide your crops with an ongoing supply of nutrients and moisture (not to mention the growth-promoting properties of worm castings). Aside from the initial labour of digging the trench and adding in a bunch of waste materials, this is a very low maintenance system. I simply pull back the upper layers of straw etc and dump in chopped up food waste (if you don’t chop it at all it can be and even longer-term slow release fertilizer). I usually mulch my lawn clippings back into the lawn, but this year I’ve actually been harvesting them to add them to my trenches, along with any weeds I pull.
Another method I’ve found to be successful is simply using waste materials as a mulch over my soil, then covering with straw (or other carbon-rich materials). I seem to have a very healthy population of composting worms in the beds where I’ve been doing this, and the plants growing in these beds seem to be doing very well. I think the key is having a large enough population of worms, and a high quality habitat for them to live it. If you simply dumped a heap of rotting waste on your plants you may find that their growth ends up stunted, or they end up diseased since these materials can contain lots of phytotoxic compounds generally produced via various anaerobic processes, and/or various plant-disease organisms. With a large worm population (and other creatures) and a nice habitat matrix (more on that in a minute), these materials are getting aerated and processed quite quickly, and all liquids are passing down through the ‘habitat’ zone, where countless aerobic microbes are likely breaking down most of the harmful compounds that might be getting produced.
This ‘habitat’ concept is something I stress a lot when it comes to worm composting. I always suggest that people set up their worm bins a week or so before adding the worms, so that they arrive to find (hopefully) ideal living conditions. The same holds true for outdoor systems as well – although it is generally easier to keep worms happy in larger outdoor systems, where they can easily move to avoid any poor conditions that develop. Nevertheless, I still recommend initially adding a lot of material from a vermicomposting system that is already up and running, or simply mixing a bunch of bedding with waste materials (food) and letting that age for a bit before adding the worms. Once this habitat is in place there is far less chance of harming your worms (or the plants for that matter), since there will always be this buffer zone where the worms can retreat if necessary.
Hope that makes sense! I’ll definitely be writing more about my various outdoor systems soon.
While the soil surface system is definitely not the best choice for an ‘all-season’ worm bed, a vermicomposting trench system should definitely help your worms to stay cool in the summer and above the freezing mark in the winter – in order to keep your system really active you will likely need to have access to a decent sized waste-stream (to help maintain adequate microbial heating). If you added some straw bale walls along the edges of a composting trench, then piled materials up to fill the space (between walls), I suspect you would have a great system for winter vermicomposting.
I personally use a big wooden worm box with a removable insulation wall (you can learn more about it >>HERE<<), but this year I will likely be testing out multiple winter composting systems. As for the best worm composting system for a family of nine, if you are looking for ultra low-maintenance, I would suggest going with outdoor trenches or pits (or a big wooden system like the one I have). If you want something you can 'play with' a little more, I recommend setting up a medium to large system indoors - a big Rubbermaid tub (preferably one that's not too deep) could work very well. I should mention that it's not a bad idea to keep at least 1 or 2 smaller systems indoors anyway, even if you do most of your worm composting outdoors. It's kinda like an insurance policy that helps protect you in case of severe weather or other hazards that can wipe out your worm population. Ok - regarding your last question, using worms as part of your landscaping is totally doable, but again you will need to provide them with a habitat where there is a lot of rich organic matter. Let's say you mulch all your gardens with wood chips - well, there is no reason you can't have food scraps, shredded cardboard etc and worms underneath munching away and adding castings to your soil. Hope this helps!