CHAPTER 3

Compost

I’m often surprised when I learn someone doesn’t compost because the process feels so natural to me. Then, when I see that same person buying compost for their garden, I’m gobsmacked! Even if you only have a small garden, composting is one of the most important activities you can do to save money and prevent waste from unnecessarily ending up in a landfill. Even more, it helps build far superior soil.

Have you ever looked closely at perfectly finished compost? Grab a handful and observe this rich, black, garden gold. It should have a uniform color, a light fluffy texture, and no strong smells. This material is the single most effective ingredient in creating a healthy garden.

Despite similar appearances, compost is not soil. Soil, as you remember from chapter 1, is made up of sand, silt, and clay particles. Compost is organic matter that has been broken down by soil microorganisms. It can be used as a soil amendment, fertilizer, and mulch, all of which allow the organic matter to integrate with the native soil to improve its structure, moisture-holding properties, aeration, and nutrition.

Hooray for compost!

Composting isn’t difficult, but it also isn’t as simple as just throwing your kitchen scraps and garden cuttings into a heap and checking on them a year later. Eventually those items will break down and create compost, but there are much faster, cleaner, and more effective ways, which I will show in this chapter.

A Compost Recipe for Success

Healthy compost results from a combination of four ingredients: nitrogen, carbon, air, and moisture. It’s important to note that more variety of materials going into the compost will mean more variety of the organisms and nutrients available in the completed compost.

The best way to keep your compost bin balanced is to ensure that no single nitrogen source exceeds more than 20 percent the volume of what you’re adding.

1 PART NITROGEN SOURCE (GREENS)

Green compost ingredients are those with higher nitrogen content, such as grass clippings, garden trimmings, and kitchen scraps. These materials rot quickly and are full of the compounds needed for fast microbial growth. They are usually quite wet and heavy and can get stinky fast unless you balance them with enough brown material. When choosing greens for your compost bin, limit any one item to no more than 20 percent of the total of greens. This will help to mitigate any issues that could come up by packing the bin with so much of one item that it quickly throws the whole mix off.

2 TO 3 PARTS CARBON SOURCE (BROWNS)

Brown compost ingredients are those with higher carbon content, such as paper, finely shredded woody material, and straw. Browns are dry and bulky, creating spaces for air to reach the greens. They do not decay rapidly without greens because they do not hold enough moisture.

AIR

Oxygen is necessary for the microorganisms munching on the materials in the compost pile to turn it into compost. While you can certainly create a pile of greens and browns and let them do their thing, adding air to the pile stimulates the microorganisms into hyperdrive and will, therefore, speed up decomposition.

Introduce air by turning the compost with a fork, an aeration tool, or using a rolling composter. As the microbes work to break down the materials, the compost heap will become warm. The heat in the middle of the pile can reach up to 150°F (66°C) and then will cool down again after about 4 to 7 days. Turning the compost weekly helps stimulate the activity again, brings the temperature up, and moves the materials from the edges to the middle.

MOISTURE

Moisture is also necessary to give the microorganisms the best possible conditions to break down the material. After adding the materials, water the compost pile and mix it well. It should be damp but not soggy. In dry months you may have to add water, and in wet months you may have to protect the compost from rain.

Are Fallen Leaves “Browns?”

Color alone is not a good indication of what is considered brown materials. Deciduous leaves that have fallen and turned brown, as well as chopped tree and shrub clippings, have higher nitrogen balance than true “browns.” Leaves and chopped-up clippings are excellent for compost and can decompose readily on their own, without a need for additional greens or browns. You can choose to compost these materials from the garden on their own or mix in with the 1 part green / 2 to 3 parts brown mixture. Just be sure not to replace all of the browns with fallen leaves or your compost will be too wet and stinky.

Keep These Materials Out of Compost

Not every material should go in your home compost bin, although some of these can go into city or county large-scale industrial compost bins where the temperatures are consistently hot enough to kill pathogens and seeds. Before you compost these items, be sure to check your local composting regulations.

• Pesticides and herbicides – Keep your garden healthy without introducing pesticides and herbicides into the compost bin.

• Compostable grocery bags – Despite their name, these should not go in your home compost bin. Use brown paper bags instead.

• Evergreen clippings – Some evergreens take a long time to compost at home and some resins can slow down and/or inhibit the composting process.

• Meat, bones, dairy, or animal product food scraps – Home compost doesn’t get hot enough to break these down effectively, and it could attract pests.

• Pet waste – Dog and cat waste can carry pathogens that could be transferred to the soil.

• Diseased plant material – Diseased or infested plants may perpetuate the incidence of disease and pests in future years.

• Plants that have gone to seed – Compost may not get hot enough to sterilize seeds.

• Large logs, thorny branches – Big, woody items will be too large to break down. Chip or grind all large, woody materials instead.

• Poison ivy, invasive weeds, and other noxious plants – Don’t risk spreading these plants by composting them.

COMPOSTING SHOULDN’T BE GROSS

If you think composting is yucky or dirty, you aren’t doing it right! Compost should smell fresh, sweet, and earthy, like the forest. Overly stinky compost is not properly in balance, but it is an easy fix.

Too many greens, too much of one type of greens, or too much water in your compost could cause it to become soggy and smell bad. Compost can start to stink when there aren’t enough carbon materials to balance out wetness. In this case, remove any of the soggy, offending materials, add more brown materials, and turn your compost to introduce air. In most cases, this will help remedy the problem.

Fruit Flies, Maggots, and Rats—Goodbye!

While healthy compost will contain beneficial bugs, bacteria, fungi, and other organisms, you shouldn’t need to fight off an army of critters to get into the compost. Rodents love to burrow into a warm compost pile to create a nest while joining other wildlife like bears, raccoons, and fruit flies for a midnight snack. Designing your compost system to restrict access to wildlife is job one, but you can also eliminate the food source that is attracting them.

Insects will certainly be attracted to your compost pile and you want them there! Flies, maggots, beetles, and more can help the material to break down. If there is a particular insect species that is overly abundant and is becoming a nuisance (I’m looking at you, fruit flies), the best defense is removing the food source that is attracting them (likely fruit) and getting the compost pile back into balance. If you keep a layer of brown on the top of the compost to cover up the kitchen waste, it should keep the insects in check.

Choosing a Pile, Bin, or Other Composting System

How you set up your composting system depends largely on your available space. You can have one or as many compost areas as you need. The key is that they should be accessible and easy to add material to, aerate, and monitor its health. If you have a large property with different zones like a vegetable garden, agriculture space, a food forest, and/or managed woodland, you will want to add different composting systems for each one to provide an easy way to compost the waste from each zone and create enough to amend the soil. If you live in a small urban space, you may need to have a small closed system, a vermicompost bin, bokashi, or use a community composting program.

COMPOST SYSTEM	DESCRIPTION	BEST FOR
COMPOST PILE	A heap of materials left to compost in place	Large farmsteads, managed woodlands
SPOT COMPOSTING	Digging a hole in the soil and burying a mix of materials to compost below ground	Any garden
WOOD SLAT BIN	A compost bin with three sides made of wood slats	Areas without wildlife attracted to compost
CRITTER-PROOF BIN	A wood bin lined with 1/4-inch wire mesh on all sides as well as the top and bottom	Urban and suburban areas with rat, mice, raccoons, and other critters
ROLLING COMPOSTER	A closed system that doesn’t sit directly on the soil. Compost turning is done by rolling the bin.	Urban areas and near homes where open bins can be unsightly
THREE-BIN SYSTEM	Three separate, side-by-side bins. One bin is for adding new material, another is left untouched to finish the compost, and a third is for finished compost available for use.	Large homesteads and farms
BEAR-PROOF BIN	Stone structure with metal top with holes for aeration	Bear country
ELECTRIC COMPOSTER	An expensive kitchen appliance that converts kitchen waste to compost in eight to twelve hours	Apartments
BOKASHI	Bokashi is a Japanese term for “fermented organic matter.” Kitchen scraps are added to a bucket with bran and closed to ferment. After a few weeks, the fermented scraps are added to a compost system to finish.	Using in combination with another composting system
WORM BIN	A vermicomposting system that feeds worms kitchen waste and carbon material to produce worm castings	All gardens
COMMUNITY OR PUBLIC COMPOSTING PROGRAMS	Green waste collection from home or businesses, or community garden compost piles that allow compost sharing. The finished material is then also shared in the community.	Composters without space to compost

Compost Booster Recipe

Quick Return Composting is a method of accelerating composting developed by Maye Emily Bruce in the 1940s. In this method, a combination of plants is added to the compost pile to finish the compost in just 4 to 6 weeks. Traditionally, QR activator is made from six herbs: nettle, dandelion, chamomile, yarrow, valerian, and oak bark. The herbs are dried and then crushed into a powder. Honey and powdered milk are added to the powder to make a mix that is sprinkled on compost layers before adding a cover or insulation layer to the pile to hold in heat while maintaining airflow.

The intricacies of the QR method are featured in a book called Quick Return Compost Making by Andrew Davenport and Maya Emily Bruce. However, you can make a simple home garden compost activator with a custom blend of any combination of the following plants.

Compost Accelerating Plants

Alpine Strawberry (Fragaria vesca)

Alfalfa (Medicago sativa)

Black Elderberry (Sambucus nigra)

Calendula (Calendula officinalis)

Chamomile (Matricaria chamomilla)

Comfrey (Symphytum officinale)

Dandelion (Taraxacum officinale)

Hollyhock (Althea rosea)

Oak Bark (Quercus robur)

Sage (Salvia officinalis)

Stinging Nettle (Urtica dioica)

Valerian (Valeriana officinalis)

Yellow Dock (Rumex crispus)

Make It!

Grow compost accelerator plants in your garden or forage for wild plants from locations where foraging is permitted and safe. However, avoid harvesting plant parts that can easily reproduce, such as roots or seeds.

1. Hang bundles of freshly harvested plants from a rack in a cool, dry location until they are completely dried and can be crumbled in your hands.

2. Remove any hard or woody stems and bark and grind the dried plant material in a coffee grinder or blender reserved for making garden recipes. Cut the woody stems and bark into smaller pieces and use the coffee grinder to finely grind the pieces.

3. When all of the plants are reduced to a powder, mix them together and store them in sealed Mason jars labeled “Compost Booster” in a cool, dry place such as an indoor cabinet.

Just Add Plants

If you don’t have the time or desire to grow, harvest, dry, and then grind the plants into compost accelerator, just toss some of the plants into the compost bin. Many gardeners grow comfrey—an exceptional compost booster—right beside the compost so they can simply cut off a bunch of leaves and stems and pop them right into the compost.

Use It!

If you are building a new compost pile, sprinkle the compost booster between layers as you build the pile. If you would like to accelerate decomposition of your existing compost, add 1/4 to 1 cup (60 ml to 235 ml) of the compost booster in the center of the pile; turn the compost to mix it in.

These Materials Speed Composting

Besides plants, manure and healthy soil are full of microbes, bacteria, fungi, soil insects, mites, and worms that will speed the decomposition process. Add a scoop of one or any combination of these compost amendments to really get the party started.

• Mushroom manure

• Well-rotted manure (not pet waste)

• Healthy garden soil

• Woodland soil from a healthy forest

DIY Vermicompost (Worm) Bin

Vermicomposting is the process of intentionally using worms to decompose kitchen scraps and carbon material resulting in worm castings (worm poop). Worm castings have a much finer texture than soil, are excellent at holding moisture, and are highly nutritious as a balanced garden fertilizer. While the N-P-K values will vary depending on what the worms have feasted on, worm poop is certainly rich with soil nutrients and microbes, making it a wonderful addition both to garden soil and compost. Above all, it’s fun to make a worm bin and employ some worms who will happily take payment in kitchen scraps and pay you in poop.

Just like composting, vermicomposting requires these four ingredients: greens, browns, water, and air. The greens can be made up of kitchen scraps or garden waste, the browns provide bedding and shelter (and the worms also digest the bedding), the water they need typically comes from the provided kitchen waste, and the air comes from air holes that are added to the bins and the loosely packed material. Unlike composting, in vermicomposting, you add a fifth ingredient: worms.

The worms used in vermicomposting bins are not the earthworms you’ll typically find in your garden. Specific varieties such as red wigglers (Eisenia fetida) and redworms (Lumbricus rubellus) are chosen because they are very active, and they love to spend their time eating and multiplying. When you create a worm bin and add a supply of worms, they will quickly get to work and start digesting the food and bedding material. They double their population each month to fill up the space that they’ve been given, but once the food supply or space becomes limited, they stop multiplying to control their own population. In most cases you won’t have to worry about dividing or increasing your worms; they will manage that themselves. It’s your job to give them a nice home, protection from the elements, and a whole lot of good food.

I have used a number of different bin designs, but my favorite is the personal design of Pau Farré, who teaches vermicomposting workshops at City Farmer in Vancouver, British Columbia. It is compact and easy to use, making it perfect for small urban composting, yet the design can be scaled to accommodate more worms and a large garden easily.

The bottom bin is used to collect the excess moisture (leachate), the middle bin is used to hold finished worm castings, and the top bin holds the worms plus their food and bedding.

Materials

2 nesting plastic bins, one with a lid

1 shallower bin in the same width

Power drill or hammer and nail

Four 2- to 3-foot-square wood blocks that can be used as risers

Dry material like shredded newspaper, straw, or dried leaves for bedding

1/2 lb, red wigglers (about 500 worms)

Kitchen scraps

Make It!

1. Drill drainage holes in the bottom of the two tall bins using a power drill or hammer and nail. Note: If the bins have uneven bottoms, drill holes in the lowest part of the bin to ensure that all the moisture drains out.

2. Make air holes on the sides of two upper bins using the same tools. The air holes should be spaced around the perimeter of the bin, above where the two bins overlap.

3. Fill one of the tall bins one-third full with a mixture of dry bedding materials as the base of your worm bin. Wet the bedding material so that it is the consistency of a wrung-out sponge.

4. Add your worms to one corner.

5. Add about 4 cups (1 liter) of roughly chopped kitchen waste on top of the worms.

6. Cover with a top layer of dry bedding; any combination of straw, leaves, or shredded newspaper will do.

7. Assemble the worm bin. Place the 4 risers in the shallow bin to provide some clearance for the leachate to drain. If you plan to scale up to a larger bin, you may need to increase the number of risers to keep the base stable. Place the middle bin on them and add a bit of bedding inside that bin for the worms to explore.

8. Place the worm bin on top and add a lid.

9. Keep the vermicomposter outdoors in a cool, shady spot in summer, and a warm covered spot in winter. The temperature should be between 5° to 30°C (41° to 86°F). In areas that have cold winters, move the worms into a garage or, if it’s not too cold, you can place a blanket over the top of the bin.

Worm Food Recipe

Worms love to eat what you give them, but having a balance of different materials ensures the environment stays healthy. Just like composting, a good rule of thumb is to make sure that no more than 20 percent of their food is made up of one material.

Materials

Kitchen scraps, such as:

Raw vegetables

Egg shells

Coffee grounds

Flowers

Green leaves from garden

Avoid: cooked food, dairy, meat, bones, vinegar, oil, citrus, or juicy produce (e.g., tomatoes, watermelon)

Also, do not include any plant seeds, as worm digestion does not create the heat necessary to sterilize the seeds. (In fact, the seeds would be thrilled to germinate in nutrient-rich worm castings!)

Special dietary needs? You bet! Worms are raw-food, gluten-free vegans.

Make It!

1. Feed the worms weekly, alternating placing the food through the four corners of the bin. By the time a month has gone by, the worms will have had time to digest the scraps in the first corner.

2. The worms can easily survive for a month without food so don’t worry if you need to go on vacation. Just feed them when you get home, and they will be happy to hold down the fort until you are back.

Troubleshooting

If the worm bin starts to smell, it’s an indication that something has gone wrong. It should be fairly easy to detect by inspecting the four corners to see where the problem lies. Perhaps there were too many acidic foods in one area, which changed the pH to be off-putting to the worms. In this case, you will notice they have migrated as far away as possible and are hanging out where the conditions are more favorable. To fix the issue, clean out the material that’s causing the problem, replace any affected bedding, and it should bring the bin back to health.

Worms Only, Please!

To prevent fruit flies, be sure that the bedding on top is dry and adequately covers the food. You can also omit the fruit or sweet scraps that attract flies. If neither of those things works, add a fruit fly trap (from chapter 5) nestled into the dry bedding at the top to attract them and drown them before they even get a taste of the kitchen scraps.

Harvesting Worm Castings

The bin is designed so the top bin contains the worms, bedding, and food, while the leachate falls through the holes into the bins below, settling in the catch tray at the bottom. The middle bin is for harvesting the castings.

Worm castings can be harvested every three to four months.

Use It!

To harvest the castings, stop feeding the worms for a few weeks until they have digested all of the kitchen scraps. Remove the dry top layer of bedding and swap the worms to be in place of the middle bin.

Set up the empty middle bin with new bedding and some kitchen scraps just as it was initially set up, but leave out the worms.

Put the freshly prepared bin on top of the one that contains the worms and castings and set the vermicomposter back in place. The worms will find their way up through the holes to get to the food.

When all the worms have finished digesting their food and migrated, you’ll have a nice, clean supply of worm castings to use in the garden.

Dividing Worms

There may be a time when you would like to divide the population to give some worms away or start a second bin. To do this, remove the dry bedding top layer, then dump the remaining contents of the worm bin onto a tarp or tray and set it outside in bright light. The worms will migrate away from the light and huddle together. Gently scrape back the material until you reach the worms and quickly move them into their new home.

Compost Tea

Compost tea is a liquid made from steeping or brewing compost and water for the purpose of extracting beneficial organisms and water-soluble nutrients. Compost tea can be used as a soil drench, which applies dilute concentrations of soil microorganisms and nutrients to populate the soil. It can also be used as a foliar spray to add microorganisms to the aboveground plant parts, which can help with plant disease. Either way, compost tea is a beneficial way of extending the reach of compost to cover the garden.

For something that sounds so simple, compost tea is one of the most controversial topics in gardening and a difficult one to properly measure. Some experts say that watering with compost tea has no more benefits to the soil than plain water, while others swear by it as a staple for growing thriving crops. This variation in opinions makes sense considering that compost can be made of so many different inputs that it would be difficult to come to a standardized conclusion on its effectiveness. Even more, there are numerous methods for making compost tea that can yield additional variables.

The way around the debate is to give it a try and test the results in your own garden. As with all of the ideas in this book, you will learn what works best for your garden through observation and experimentation.

Common Sense and Safety with Compost Teas

Making compost teas is a simple process, but there is a potential for error when brewing microorganisms. You could end up increasing harmful organisms rather than beneficial ones. Here are some common-sense tips for working with compost tea:

• Start with an excellent quality finished compost. It should smell clean and fresh, not stinky, and it should be fully composted with little variation in the size or color of the particles.

• The water used should be either rainwater or dechlorinated water. Set an uncovered bucket of tap water out for 24 hours to allow the chlorine to evaporate.

• Do not use manure as an ingredient in compost tea.

• The resulting compost tea, whether it’s an extract or an aerated brew, should also not have a strong odor. If the resulting tea smells like it has gone bad, it probably has. Do not use it in your garden.

• Use compost tea and extracts immediately when the brewing is complete. It should not be stored or set aside for later application.

• Test your homebrewed compost tea method on some container plants or one area of your garden that doesn’t contain edible plants.

• Tea can also be sent for lab tests or inspected under a microscope.

• If you have any question about your ability to brew compost tea at home, search for a local workshop on making tea for personalized training suitable for you, your garden, and your geographical area.

Nature’s Method: Topdress the Soil with Compost

The easiest and most natural way to feed your garden with compost tea is to allow Mother Nature to brew it for you. This method is particularly effective if you have a large amount of properly finished compost available to spread around your garden as you will need at least 1 to 2 inches (2.5 to 5 cm) of compost to topdress the soil. After that, cover the compost with 2 inches (5 cm) of mulch. This creates a protected layer of organic matter and microbes that will continue to break down and become part of the soil structure. Rain and garden watering will allow the compost tea to percolate down into the soil and allow the nutrients to be available to plants.

Grandmother Method: Compost Dilution

The first method of making liquid compost is the Grandmother Method, also called compost extract, anaerobic compost tea, or non-aerated compost tea. This is the common method of diluting compost passed down through generations.

It’s similar to brewing yourself a cup of herbal tea. When you steep mint leaves or chamomile flowers in water, it infuses the water with the water-soluble nutrients that are more readily available for your body when they’re sipped. To get those nutrients, you can certainly just eat the dried plant material, but it’s not as gentle or as easy to absorb as a cup of tea. That said, you would get more fiber from eating the plant material, and that would help to fill up an empty stomach. This is an important connection to the garden because if you are using compost tea on your soil, it should have organic matter already present before you apply. Adding compost tea to depleted soil doesn’t give the compost microorganisms anything to eat once they dive into the land.

Materials

1 part excellent quality finished compost

20 parts rainwater or dechlorinated water

Watering can or bucket

Make It!

Combine the compost and water in a watering can or bucket. Allow the compost to steep for 1 to 4 hours, stirring at least two to three times. When it’s time to apply it to the garden, stir it well to mix the sediment in with the water. No need to strain out the compost that is left over; it can be watered into the soil with the liquid.

Alchemy Method: Aerated Compost Tea

In the Grandmother Method, I used the metaphor of steeping a cup of herbs as an example of how anaerobic compost tea is beneficial. Now, what do you think would happen if you left a cup of herbal tea steeping on the counter for a few days or a week? That’s right, it would go bad. By “bad,” I mean that after a day or so the warm tea and decomposing herbal tea create the perfect environment for bacteria to grow. If you left the tea on the counter like that for a week, I would not recommend drinking it!

The beneficial microbes in compost love air, while the bad bacteria typically enjoy stagnant, unaerated water.

In this system, air is continuously pumped into a bucket containing water and compost to brew more of the beneficial microbes. A compost tea brewer can be purchased as a kit or made at home using a 5-gallon (19 L) bucket, a nut milk bag, and an aquarium air pump. Visit https://gardentherapy.ca/compost-tea-brewer/ for the steps to make the brewer I use.

Materials

5-gallon (19 L) bucket compost tea brewer

Large 12- x 12-inch (30- x 30-cm) nut milk bag

1 cup (235 ml) excellent quality finished compost

1 cup (235 ml) worm castings

1 tablespoon (15 ml) soluble seaweed

Rainwater or dechlorinated water

Make It!

1. Add the water to the brewer and run the aeration for 1 hour.

2. Add the remaining ingredients to the filter bag and add to the water. Follow the instructions that accompany the brewer you are using.

3. Continue aerating for 24 hours at 72°F (22°C). If it is warmer, then decrease the brewing time, and if it is colder, increase the brewing time.

4. Strain the compost tea and apply to the garden immediately.

When cleaning up, thoroughly wash anything that was in contact with the organisms well to remove the biofilm and be ready for the next use.

Vermicompost Tea

Vermicompost tea is a liquid dilution of vermicompost with water. Dilute 1 part vermicompost with 10 parts water and let it sit for 1 to 12 hours. Use the dilution as a soil drench or foliar spray.

Leachate or Compost Tea

Leachate is the liquid that runs off compost and vermicompost bins as the compost materials break down. While most compost piles have direct contact with the ground soil, bin systems with closed bottoms need to have drainage holes and a catchment system for the liquid runoff.

This liquid is sometimes called compost tea; however, it is more accurately called leachate from the composting process. Compost tea is a dilution of finished compost, while leachate from compost or vermicompost bins consists of the excess moisture from the materials at all stages of composting. Fruit and vegetable juices can collect in the catchment as can rainwater. This is not necessarily the product of the microbial and chemical actions of composting; therefore, it can have very different properties. It could be made up of some finished compost runoff along with the excess liquid from that juicy watermelon you added to the bin.

Leachate can be strained using a fine-mesh strainer to remove any seeds that could still be viable. The leachate can be filtered from the catchment and added to the soil, although it’s not clear what sort of benefit it could have considering it would be nearly impossible to tell what it contains.