Gardening Without Animal Products

A Guide to Growing Plants Free from Slaughterhouse Waste—Bone Meal, Feather Meal, and Chicken Manure

Apr 23, 2025

My garden just as spring is bursting (with my beautiful cat Michiko)

The Nutrients People and Plants Need Are Not from Animals

One of the most persistent—and disempowering—nutrition myths we’ve all been fed (pun intended) is the idea that the nutrients our bodies need are only found in animal products. We’re told we have to get calcium from cow’s milk, omega-3 fatty acids from salmon, and iron from animal flesh. The underlying message is that abstaining from animal products will inevitably leave you deficient in essential nutrients.

Nothing could be further from the truth.

The reality is, animal flesh and fluids are not the source of calcium, omega-3s, or protein—they’re just the carriers. They’re the middlemen. For instance:

Cows have calcium in their milk because they eat calcium-rich green plants (or more accurately, calcium supplements provided by the dairy industry).
Fish contain omega-3s because they eat the phytoplankton that actually produce those fatty acids.
Iron — like all minerals — is found in the soil itself. We mine minerals from the earth, not from animals.

In other words, the nutrients we need are plant-based. Not animal-based.

Just as we’re told we need to eat meat, dairy, and eggs when what our bodies really require are calcium, omega-3 fatty acids, and iron (among other things), we’re also led to believe our gardens need animal products like bone meal, blood meal, feather meal, fish emulsion, and chicken manure—when what they actually need are nitrogen, phosphorus, and potassium (plus other vitamins and minerals).

Just as with humans, it’s not animal products that plants need; it’s nutrients. When we talk about needing protein, iron, calcium, and omega-3s, what we really mean is that we need amino acids, minerals, and fatty acids. In the same way, what plants need are nitrogen, phosphorus, potassium, and a spectrum of vitamins and minerals. Not animal products.

Slaughterhouse Byproducts Are Not Harmless

I often hear people say there’s no harm in using slaughterhouse byproducts, arguing that they’d just go to waste otherwise. The reality is, slaughterhouse byproducts aren’t just “waste”—they’re big business. Just like leather, these products generate significant profit for the animal agriculture industry. By selling things like bone meal, blood meal, and feather meal, slaughterhouses create an additional revenue stream that helps prop up and sustain the entire system.

And this idea that we’re innocently making use of what would otherwise be wasted misses the bigger picture. These byproducts aren’t harmless leftovers—they exist because animals are bred and killed in the first place, and that process generates enormous, unnecessary waste, none of which needs to exist at all. And it doesn’t end with blood, bones, hooves, heads, and feathers on the slaughterhouse floor.

The resources required to bring animals into this world only to kill them are staggering—enormous amounts of water and land, along with the significant greenhouse gas emissions generated by animal agriculture. In fact, the livestock sector is one of the leading contributors to methane and nitrous oxide emissions, both of which are far more potent than carbon dioxide.

Then, in the slaughterhouse itself, you have terrified animals fighting for their lives, and workers who are inured to their own compassion as well as to the suffering of the animals. It’s an inherently violent system that takes a toll on everyone involved. This is what we’re supporting when we buy meat, dairy, and eggs, but also when we buy fertilizers and compost that contain chicken manure, steer manure, blood meal, bone meal, hoof meal, horn meal, feather meal, fish emulsion, or fish heads. All of these are direct byproducts of animal agriculture and slaughter, woven deeply into conventional gardening and farming.

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brown horse with black eye — Photo credit: Pieter van Noorden

Animal Waste in the Garden

Animal-based fertilizers go beyond blood and bone meal; products like bat guano, seabird droppings, and even worm castings are also widely marketed to gardeners. These might sound less harmful at first glance, but their stories are often more complicated—and more problematic—than most people realize.

Chicken Manure

One of the most popular animal-based fertilizers is chicken manure. But it’s important to remember that, like bone and blood meal, chicken manure is a slaughterhouse byproduct. And even if you picture “free-range” chickens from small local farms, the chicken manure sold as fertilizer is not coming from your neighbor’s backyard flock. It comes from large-scale, industrial animal factories—part of the same system of exploitation and waste as every other animal product.

Bat Guano

I used to think that harvesting bat poop sounded pretty harmless. You go into a cave, you scoop up the droppings, you leave. No one gets hurt, right? Well, it turns out the story is much more complicated—and troubling.

Bat guano is harvested from caves and from islands where seabirds have lived for centuries. Peru became famous in the 19th century for exporting guano from the Chincha Islands off its coast, and there’s still debate today about harvesting what little remains. Guano was once so valuable that it led to the Guano Islands War (also called the Chincha Islands War) in the 1860s, when Spain clashed with a coalition of Peru, Chile, Bolivia, and Ecuador over control of these islands.

But beyond the politics, there’s a serious environmental impact. Guano deposits are the foundation for entire cave ecosystems—cave-adapted invertebrates rely on bat feces as their only food source. Remove the guano, and you disrupt these fragile ecosystems. Worse, harvesting guano can be dangerous for bats themselves. Bats are extremely sensitive to disturbances; some species, if disturbed repeatedly, can actually starve to death. Others may drop their young out of panic, leading to population decline. Studies in places like Jamaica have shown that guano mining is the biggest threat to bat caves, leading to the loss of bat species and the creatures that depend on them. So, for me, guano is off the table.

Worm Castings

Worm castings—another word for worm poop—are often seen as a more ethical fertilizer. And compared to slaughterhouse waste or guano, the harm is definitely less. Commercial worm composting involves keeping worms in dirt-rich environments, feeding them kitchen scraps, and collecting their castings. But even here, I hesitate. On a small scale (like home vermicomposting), it might be fine, but I’m not convinced that large-scale commercial operations are as ethical as they sound. Until I know more about how worms are bred and treated, I’d rather stick to other soil amendments.

And honestly, when you’re gardening with native plants, most of them don’t want—or need—fertilizer or amendments at all. It’s just one more reason to prioritize plants that are native to your area.

The Foundation of Healthy Plants: Soil

Just like us, plants thrive on a balanced, nutrient-rich foundation. For humans, that means a healthy plant-based diet—rich in vitamins, minerals, fiber, macronutrients, and phytonutrients; for plants, it’s healthy, living soil—rich in minerals, organic matter, and microorganisms. While supplements in both cases can help address specific nutrient deficiencies, nothing replaces a solid, healthy base.

You can create and maintain fertile, nutrient-rich soil—without animal products—by focusing on these tried-and-true methods:

Mulching

Applying organic mulch helps retain moisture, regulate temperature, suppress weeds, and, as it breaks down, adds nutrients to the soil. While you can buy commercial mulch like wood chips or shredded bark, one of the best things we can do for biodiversity in our yards is to let autumn leaves act as natural mulch.

Instead of clearing every leaf, leave them in your garden beds or use them as groundcover. You can clear them off hardscapes like patios and walkways, but in your garden, those leaves enrich the soil, feed beneficial microorganisms, and provide essential habitat for insects and other small creatures.

Also, keep in mind that while mulching benefits many plants, it’s also important to leave some bare patches of soil for ground-nesting bees and other pollinators that rely on exposed ground.

Plant Rotation

If you grow vegetables, rotating crops each season prevents your soil from being stripped of the same nutrients year after year and helps control pests and disease.

Composting

Compost is often called “black gold” for gardeners. Making your own from kitchen scraps and yard waste is the best way to control what goes in, but you can also find high-quality, animal-free compost from reputable sources. For some of my plants, I use a rich compost called Wondergreen from American Soil and Stone—it acts as both compost and mulch and contains no animal products. Wherever you live, just ask around for a plant-based compost option near you. Homemade or store-bought, it’s an easy way to nourish your garden without animal inputs.

photo of fully bloomed orange petaled flower plant — Photo credit: Harshal S. Hirve

When Plants Need a Nutrient Boost

Even with healthy soil, plants sometimes need a little extra support. That’s when it helps to know which nutrients do what. The three primary nutrients essential for plant growth are nitrogen, phosphorus, and potassium—these are the familiar N-P-K numbers you see on fertilizer bags.

Each bag lists three numbers (like 5-10-5), which indicate the percentage by weight of each nutrient: the first is always nitrogen (N), the second is always phosphorus (P), and the third is always potassium (K). For example, a fertilizer labeled 5-10-5 contains 5% nitrogen, 10% phosphorus, and 5% potassium. Understanding these numbers helps you choose the right fertilizer for your plants’ specific needs—whether you’re aiming for more leaf growth, stronger roots, or overall plant resilience.

Nitrogen (N) promotes leaf and stem growth. While most plants need nitrogen for healthy, vigorous foliage, too much can cause excessive leafy growth at the expense of flowers and fruit—and may burn leaf tips. Signs of excess include very dark green leaves and few or no flowers or fruit. Too little nitrogen shows up as light green or yellowing leaves and slow growth, especially in older, lower leaves.

To add nitrogen without animal products, try cottonseed meal, alfalfa meal, flaxseed meal, or soybean meal.

Phosphorus (P) is essential for root development and flower production. Plants like bulbs and root crops benefit from extra phosphorus, and high-phosphorus fertilizers are sometimes marketed as “flower boosters.” Signs of phosphorus deficiency include deep green, red, or purple leaves, poor blooming and fruiting, yellowing lower leaves, and stunted growth.

Instead of animal-based bone meal, use rock phosphate or biochar (charcoal made from plant material).

Potassium (K) is critical for overall plant health, supporting strong growth, immunity, and disease resistance. A deficiency may result in tall plants with weak stems and yellowing or browning of leaf tips and edges.

Good plant-based potassium sources include kelp meal, seaweed, and wood ashes.

Troubleshooting at a Glance

If you’re unsure what your soil needs, you can have it professionally tested or use a home test kit. Often, though, your plants themselves will tell you what’s missing:

Few flowers: Often a sign of phosphorus deficiency.
Yellowing leaves: Usually points to low nitrogen.
Stunted growth: May indicate a lack of potassium.
Browning leaf edges: Could mean calcium is low—add lime or gypsum.
Curling leaves: Sometimes a sign of boron deficiency.
Pale or mottled leaves: May signal iron deficiency—try chelated iron.
Wilting: Could be due to low potassium, but also check water and root health.

While you can find single amendments such as the rock phosphate, cottonseed meal, alfalfa meal mentioned above, many garden centers now carry animal-free fertilizer blends. For example, Down to Earth makes a “Vegan Mix 3-2-2” using only plant-based nutrients. The options for vegan gardening products are growing—just check the labels.

selective focus photography of snail on plant — Photo credit: Krzysztof Niewolny

Managing Weeds, Disease, and Uninvited Garden Visitors

Plant health isn’t just about nutrients; it’s also about managing weeds, fungi, and those unwelcome garden visitors—all without resorting to harmful chemicals or animal-based solutions.

Weeds
Hand-pulling is the most environmentally friendly method and the most effective. In other articles, I’ll be sharing more about sheet-mulching, hand-pulling, and vinegar spray as a means for suppressing weeds and exhausting their seed banks. Mulching with leaves, straw, or wood chips also helps suppress weed growth naturally—plus, it improves soil health as it breaks down.

Fungal Issues
Promote good airflow between plants and avoid overhead watering to help prevent fungal diseases. If you spot signs of fungus, try using a homemade spray with diluted baking soda or neem oil. Always remove and dispose of any heavily infected plant material to stop the spread.

Snails
Snails can be picked off by hand or deterred with copper barriers, which they hate to cross. Some people use beer traps, but those actually drown the snails. The goal is to deter, not kill.

Insect Intruders
Neem spray is a natural, plant-based solution that helps keep aphids, thrips, and whiteflies in check—without harming pollinators.

A Note on Pesticides
Avoid neonicotinoid-class pesticides and herbicides, like Roundup, as they’ve been shown to harm pollinators and beneficial insects. If you feel you must use something, opt for less harmful alternatives such as Bacillus thuringiensis (Bt), diatomaceous earth, or insecticidal soaps.

Navigating This Imperfect World

Many of us avoid animal products because we don’t want to support the inherently violent slaughter industry. But here’s the catch: even when we buy only plant-based foods, those plants might still be grown with fertilizers made from the blood, bones, and bodies of slaughtered animals.

So, this is when I come in to remind you: don’t do nothing because you can’t do everything. Do something—anything. Maybe that means growing some of your own food, joining a community garden, supporting organic farms that use fewer animal by-products, or simply asking questions at the farmers’ market.

The bottom line? Neither you nor your garden needs animal products to thrive. Healthy soil, thoughtful choices, and a bit of compassion are all it takes.

Speaking of Supplementing…

Just like I give my plants the right nutrients when they need a boost, I also make sure my own diet fills in any gaps. I get plenty of vitamins and minerals from a plant-based diet, but Complement helps cover those small yet essential needs. I take Complement Essential as my daily multivitamin for B12, D3, iodine, zinc, and magnesium, and as part of my strength-training and muscle-building routine, I fuel up with their clean, unsweetened Unflavored Organic Protein (made with five real food proteins—nothing else!). With Complement and my nutrient-rich diet, I have everything I need to fuel my body, support my strength, and thrive so I can do my work in the world.

Give them a try and get 15% off everything you order, every time you order, using THIS LINK and the code: JOYFULVEGAN.

I’d love to know how your garden grows!