Cow Manure: How to Turn Poop into Peat

It may be smelly and gross, but no gardener can deny the benefits of cow manure. Using this as fertilizer is an age-old practice that can bring overworked soil back to life. It contains loads of nutrients that will boost your plants’ growth and livelihood. Not to mention it’s completely organic!

In this article, we’ll touch on the basics of transforming cow dung into a valuable additive for your garden beds. In fact, by the time you’ve journeyed through this information with us, you’ll find manure isn’t as smelly and gross as you thought! So, let’s take a look at how to make the most of the cow’s gracious gift.

Manures You Can Use:

What Is Cow Manure?

Cow Manure
Cow manure is an incredible fertilizer and soil amendment for gardening. Source: NefcoNordic

You may think cow manure is just poop, but it’s actually so much more than that. Cattle typically feed on grain and grasses that contain lots of nutrients, even after being digested. When manure is cleaned out of a cow’s stall, it brings with it the hay, straw, or any other organic matter on the ground. Those, plus the digested plant matter in the dung makes for one nutritious load of crap.

Cow manure contains most of the macro and micronutrients required for plant growth, particularly nitrogen (the most important). Overall though, this is a fairly balanced fertilizer, with the lowest nitrogen content of all the popular animal manures. The exact NPK values vary based on what the cow is fed, what bedding it has, and even its age. Usually, this amount falls around 3-2-1. You’ll find that it works for almost any plant, from ornamentals to vegetables.

So why cows? Of course, you can get manure from any animal, but only some are suited for gardening. It’s extremely important that your manure comes from a plant-eater because carnivorous animal waste can contain dangerous pathogens. Chickens and horses are popular choices for manure. Cow manure, though, is lower in nitrogen than those two which makes it more versatile in the garden. Nitrogen contributes to leafy, green growth in plants and vegetables, which can take energy away from flowering and fruiting crops. Because it’s balanced, you can use cow droppings on practically anything.

There’s plenty to go around because cow manure is larger in mass than chicken and horse manure. Also, cattle are raised all over the United States, so it’s pretty easy to get your hands on some manure (with gloves of course!).

Now, you can’t just haul manure onto your garden beds fresh from the cow. It has to be composted first. In its original state, manure is high in ammonia and can quickly burn and dehydrate plants – the opposite effect we’re going for. Fresh or incorrectly composted manure may also contain invasive weed seeds, or worse, harmful pathogens. 

Composting will sterilize the manure so nothing harmful is passed on to your garden. If you still feel unsure about its safety though, you can always ask your supplier what, if any, chemicals the cows are exposed to.

Benefits of Using Cow Manure

Manure in field
The manure is often mixed with straw, hay, and other brown compostables. Source: Squirrel Nation

There are plenty of benefits to list, so we’ll start with the most important – how manure helps the soil. Our minds always jump to nutrients when we think of this, but cow droppings are also an excellent soil amendment. They help aerate the soil, transforming clumpy clay into loamy goodness. This also boosts the soil’s ability to retain moisture, which means less watering for you!

Composted cow droppings are also organic, which is a huge selling point. It brings no danger of chemicals to your plants. Even if the cattle were given medication or grazed on pesticides, composting eliminates these chemicals. Manure is also an extremely natural way to fertilize. Even without human intervention, it would slowly process itself and return nutrients to the soil.

When used correctly, manure rarely burns plants. Instead, it boosts their growth and makes a more productive garden. This is a time-tested method that gardeners keep coming back to. Also, it’s very inexpensive or even free. What more could a gardener ask for?

Drawbacks of Using Cow Manure

There are some drawbacks of using cow manure for gardens, but most can be avoided by composting properly. If this isn’t done, the resulting fertilizer can be polluted with chemicals that may cause damage. It may also contain fertile weed seeds that will be a pain to eliminate later. Most importantly, manure can carry threatening bacteria, such as E. coli. By composting correctly though, you can eliminate these dangers.

Of course, there’s one obvious drawback to consider – the smell. Most people, especially your neighbors, don’t appreciate the musky perfume of cow droppings. However, the smell goes away during composting, so you won’t have to deal with it for long. On hot days, composted dung may smell faintly of cows, but not strong enough to worry. If you absolutely can’t stand the stench, you can always buy pre-composted manure from a gardening store.

How To Compost Cattle Manure

To say composting is important is a huge understatement. This is the most vital part of the process and must be done correctly. Luckily, composting is much easier than it seems!

In order to get a good carbon-nitrogen ratio, the manure has to be a blend of poop and bedding material, like straw. If needed, mix in some brown leaves, straw, or other organic material.

Hot Composting

Manure pile
Manures can be composted in a large pile or using many other methods. Source: Putneypics

This is the most popular and safest method. It makes use of the fact that when organics break down, they release heat. Hot composting uses this heat to sterilize the manure as it breaks down. We encourage the decomposition process by supplying the microorganisms in the soil with what they need to work – air, water, and organics.

You’ll need to make a large, dome-shaped, pile of manure. About 3 feet tall and wide is the recommended size, but you can go larger, especially if you have farming machinery to move it. The larger the pile is, the more work it will be, so be realistic about how much time you’re willing to invest in this. Keep in mind though that too-small piles won’t build enough heat to decompose correctly.

If you live in an area with frequent rain, make your pile under a roof so it’ll be protected. Otherwise, you can just cover it with a tarp if the weather turns bad. You’ll also want to place it away from your house, water sources, or recreational areas (it will smell at first).

Once your pile is placed and formed, give it a good soak with the hose to jump-start the decomposing process. It should be kept moist, but not soaked, during the whole process. You can test the moisture by taking a handful and squeezing it. If a few drops of water squish out, the moisture is perfect. Anything more or less needs adjusting.

It may take anywhere from a day to a month for the pile to start heating. Cold weather may slow this down, so cover the pile with black plastic if needed. Routinely check the internal temperature with a composting thermometer. The goal temperature is around 130°F, which is hot enough to sterilize the manure. 

When your pile has been about 130°F for three consecutive days, it’s ready to turn. Using a compost fork or scoop shovel, remove the outer layer and dump it into its own pile. Then, move the remaining compost, which is hot, onto that second pile. This allows the pile to heat evenly and also provides extra aeration for the microorganisms.

Water the pile and let it heat up for the second time. Once again, check the temperature with your thermometer and ensure it heats to 130°F for three days. After this, let the pile sit until it’s loamy, dark, and smells like soil. This can take a few days or months. If you’re composting a large pile, you may need to turn it more than once to ensure everything heats up.

Very rarely, composting material can overheat and combust. If you ever see your pile smoking, immediately water it to cool things down.

Vermicomposting

There’s been a great success with feeding cow droppings to worms, both as a bedding medium and as a food. This method of composting is excellent if you already have a worm farm. You’ll just be replacing the worm’s usual food with compost. If you’re new to vermicomposting, learn about worm castings here.

You’ll start with plopping manure into a pile, watering it down a few times, and letting it age. This gives it time to get past the heating stage so you won’t cook the worms. Watering it from time to time will help it age and rinse away ammonia buildup and any residue of de-worming medication the cow was given.

Once aged, move the pile into your worm bin, in place of the worm’s usual food. If you only have a small amount of dung, you can spread a 2-4” layer on top of the existing worm food without aging. Because this is such a small amount, it won’t heat up enough to hurt the worms. The most popular worm choice here is Eisenia fetida, the red wiggler. However, there are several types of composting worms you can choose from.

Now that the manure is in place, you can leave your little composters do their thing. The worms will eat the dung and transform it into worm castings. These castings, combined with leftover compost, are referred to as vermicompost. It will be dark in color and fine-grained in texture. Because the manure has aged and been processed by the worms, it’s safe for use in the garden. After separating the castings from the worms, you can apply them directly to the soil or use them for compost tea.

Can Cow Manure Be Composted Other Ways?

You aren’t limited to worms and piles of dung. Many gardeners choose to go the lasagna route. Far from a delicious meal, this method layers fresh manure with other carbon-dense materials. The manure is referred to as the “green” layer and the other materials are “brown”. 

The brown layer is made up of carbon-rich organic materials, like cardboard, wood chips, straw, dry leaves, or paper. Most cattle bedding is brown material, in fact! Brown layers should be about two times as deep as green layers. When the layers are in place, water them down with the hose. The lasagna needs to sit for a month. During this time, the layers will heat up and cool, turning into usable soil.

Manure can also be tilled into your garden’s soil and then left to break down. After tilling, cover the ground with black plastic to smother weed growth and let it decompose for a season. If you choose this method, do it in a part of your garden that you aren’t planning to plant in for the year.

You can also use a composting tumbler instead of a pile. These are designed to discretely hold the fertilizer and make turning it very easy. You’ll still need brown materials in this method, too!

Lastly, you can turn cow droppings into biochar, a pyrolyzed organic medium. This process uses high heat and low oxygen to turn organics into a charcoal-like substance. It has excellent water-retentive properties yet still aerates the soil. 

How To Use Cattle Droppings

Steer manure delivery
You can buy composted manure in bulk, or just purchase a bag here and there. Source: Squirrel Nation

Cow manure compost can be used as a soil amendment and fertilizer. It can also replace soil entirely, but we recommend just mixing it. Because of its balanced pH, it can be used for just about any plant.

Mix a 2-3” layer of your fertilizer into the soil until it has the desired consistency for your plants. You can also just spread a ½” thick layer on top of the soil (1” for very poor soils). Be sure to apply the fertilizer in areas far from water sources so it won’t leach into the water.

Often, a composted medium is used as a topper for lawn grass seedlings. It can be added to landscaping, gardens, and even houseplants. In some cases, fertilizer can be used as mulch, but it also benefits from being laid under mulch itself.

If you have leftover fertilizer that you just can’t use, share it with your friends or neighbors. Don’t store the same unused fertilizer in your yard for years.

Where To Get Steer Manure

Store-bought fertilizer can be hard on the wallet, which is another reason why we love cow manure – it’s free! Well, that depends on where you get it. If you raise cattle or know someone who does, you’re likely to have more than you need. If not, find a nearby dairy farm and ask if they have any poop to spare (they likely do). Some farmers will process the droppings themselves and sell it, which may be a cheaper option than buying from a retailer.

Most big-name garden suppliers, such as Home Depot and Lowe’s, sell many different brands of composted cow manure. You can also buy it directly from suppliers, like Black Kow, or on Amazon. Here are some of our favorites:


The Green Thumbs Behind This Article:

Rachel Garcia
Succulent Fanatic

Clarisa Teodoro
Researcher

Lorin Nielsen
Lifetime Gardener

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Last update on 2020-08-04 / Affiliate links / Images from Amazon Product Advertising API