DIY Soil Fertility – Part 1: Vermicompost

Welcome to DIY Soil Fertility For Homesteads!

This post series covers the many ways you can build fertility, create soil, cycle nutrients and take responsibility for “waste” streams on your property – all with materials and substrates you are likely buying already or can be sourced for free or very low cast. These systems all integrate with one another to enable you to in-source your soil fertility inputs instead of relying upon centralized commodity supply chains. By employing these systems together in an integrated system you will improve nutrition (for soil and humans) and save dollars, while making living soil fertility enhancers better than anything you can buy at the store. The posts are written from our own experience and are geared towards the DIYer, though options are provided for ready-to-go purchased systems as well. Check the link tree below or at the bottom of the post to explore the rest of the series!

What is vermicomposting?

Vermicompost systems employ compost worms (Eisenia fetida) – a.k.a. red wigglers – to transform a wide variety of organic wastes into nutrient-rich worm castings. The worms don’t actually eat the organic material – they eat the microbes that are breaking down the organic material.

Why do vermicompost?

The worm castings (worm poop) are an incredible garden fertilizer, and can be brewed into aerobic teas and applied to soil and plant surfaces alike to further increase their beneficial impact on soil fertility, disease resistance and plant nutrition.

The worms and their partner bacteria can process quite a lot of food scraps and other organic wastes for their relatively small footprints. Well managed worm-farms (not difficult to do) can also be kept inside – even apartment dwellers and high-density suburbanites can do vermicomposting. Vermicompost systems are an excellent way to close the loop on an immense amount of “waste” that would otherwise be hauled away by a giant truck to a landfill or commercial composting facility (you paid to get – why pay to have it taken away too!?).

Vermicompost Systems

Pre-made vermicompost systems come in a myriad of different shapes and sizes – you can also build your own. YouTube and the internet-at-large abound with DIY worm farm designs.

DIY Systems

• Self-Draining Bath-Tub System
• In-Ground Vermicompost – for in-situ fertilization right where your plants and trees can use it!
• Stacked Worm Bins – easy to make your own, some extra labor involved with stacking, re-stacking and sifting out worms – but effective for a typical household.

Done-For-You Systems

• The Worm Tap – Vertical Worm Composter AND Compost Tea Brewer – see Diego Footer’s video walkthrough of the system. Easy integration for hydroponic growers.
• The Urban Worm Bag – flow through style system with breathable bag – also on Amazon.
• Worm Factory 360 – stacked tray design built for airflow.
• Can O Worms (picture below) – we’ve been using this for nearly 15 years – requires stacking/unstacking to harvest, but it works!

What To Feed Your Worms

• YES: vegetable and fruit scraps (raw and cooked), egg shells, garden weeds, cardboard (soaked, torn into small pieces – non-glossy, remove tape and adhesive labels), newspaper.
• NO: oils, fats, raw meats, bones, citrus rinds and citrus fruit, alliums (garlic, onions etc), pet feces.
• SOME: Lawn clippings (add in very thin layers), nut pressings (from making almond milk etc).
• A LITTLE: Cooked meat, cooked fish, bread, pasta, pastries, dairy products (not liquid milk – can cause anaerobic conditions due to excess liquid, but cheeses, yogurts OK).

Worm Sources

• WormFarm.com – bulk worm orders, starting at 10,000 and up.
• GreenGregsWormFarm.com – red wigglers and worm bin DIY plans.
• Uncle Jim’s Worm Farm
• TexasWormFarm.com
• Gardener’s Supply Company
• or get them from a friend who already has a worm bin (if they are so generous)!

Starting Your Vermicompost System

Bedding

No matter what type of vermicompost system you buy or build it will need to be started off right. The worms will need a moist (not wet and not dry) bed of material along with some food to get started. The bedding and moisture is especially important if you are mail-ordering your worms (some of the larger worm farms send them in sphagnum moss that is too dry and the worms can get severely dehydrated during shipping).

Bedding materials can be finely shredded newspaper, leaf mold, finished compost (not hot or “young” compost, this can kill your worms), shredded cardboard, rotted sawdust, rotted wood chips, or best of all, a mixture of several of these substrates. Materials need to be wetted and then drained and squeeze of excess moisture (take the material and squeeze it hard in your hands – keep doing this until no more droplets come out).

Putting Your Worms To Bed

Don’t bury your worms! Once the bedding is prepared, just add them on top. If they are dry from shipping perhaps lay a piece or two of wet newspaper over them to provide additional humidity and light protection. Provide only a small amount of food at first and watch to see when they have consumed it. Mail-ordered worms can sometimes have a few days of rehydrating before they begin to eat their standard bodyweight-per-day quantities.

Ideal Conditions

Worms like things to be cool and moist – that is when they’ll do their best work. Not too cold (if its really cold outside, they’ll retreat to the center of the bin) and not too hot (they’ll be on the walls, or escaping), but just right (they’ll be in the top few inches, and often on the surface, eating and breeding).

Harvesting The Castings

Depending upon which type of system you buy or build there will be different methods for harvesting your castings, some of which require more work and greater frequency of tending than others. Most important is to choose a system that fits your needs, both in terms of food waste output and your desired application (hydroponics? vermiponics? raised bed gardening? broad acre application? worms for fish food? etc…). Some systems (like our flow-through vermicomposter pictured below) do not require stacking / unstacking. Others, like bath tub style systems, may require sequential feeding at different ends of the tubs to draw the worms away from your harvest area. Purchased systems will all come with instructions for harvest with minimal disturbance to the worms.

Using Your Worm Castings

Worm castings are black gold for gardeners. Our favorite way to utilize them (and maximize their goodness) is by brewing an aerobic compost tea from a handful of castings and other Indigenous Micro-Organisms (IMO’s). You can also put a handful of them into the hole with whatever you are planting, but if you want them to go their furthest, brewing tea is your best bet.

The leachate that will be produced by your vermicompost system is also a very valuable garden input. It should be diluted at least 10:1 with water before application to the garden, and should be used daily. If allowed to sit, the high nutrient levels in the leachate will be consumed by anaerobic bacteria and the liquid will start to stink. If this is the case, it can still be used, but should be aerobically brewed for at least 24 hours to kill all anaerobic bacteria. The nutrient will still be there – you just don’t want to toss a bunch of harmful bacteria on your plants or in your soil! You can also use the leachate to bind up chlorine/chloramine in tap water if your local water supply is treated with these chemicals before brewing compost tea.