Bone Meal: Friend or Foe? Learn How to Use It in Your Garden

Bone meal is an organic fertilizer derived from – you guessed it – bones.

Meat bone waste from slaughterhouses undergoes a steaming process before being pulverized into granules or powder for use as a soil amendment.

Rich in phosphorus (P), it also contains calcium and a trace of nitrogen.

Vertical image of a green gloved hand and arm clothed in a gray sleeve sprinkling bone meal onto loose brown soil in a garden bed, with a pile of flower bulbs and a soil knife with an orange handle, printed with green and white text.

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Should you use it in your garden? Let’s find out.

Soil Sense

Fertilizers occupy a lot of shelf space in garden centers.

Packages promise lush foliage, vibrant blossoms, and plentiful fruit if applied per manufacturer instructions. But what they don’t always mention is that they may be totally unnecessary.

A small gray and white dog with a black collar sits to the right of a green plastic back of organic bone meal fertilizer, a pile of flower bulbs, and spade with a yellow and dark green handle, on a gravel driveway with a tall green evergreen, a white house, other trees, and a green lawn in the background.
Photo by Matt Suwak.

The only sure way to know if you should apply bone meal to your garden is to test a soil sample for nutrient deficiencies. Check out our article on the topic, then contact your local agricultural extension service for more information.

Garden dirt that is not deficient in P not only doesn’t need it, but may be harmed by its addition.

Soil teems with microbes that work in tandem with nutrients to provide plants with the energy they need to thrive. Per the Colorado State University Extension, the application of phosphorus to soil that doesn’t need it may result in chlorosis, a yellowing of leaves due to impaired chlorophyll production.

A row of brown papery flower bulbs is planted in loose soil with a hand in a green flower patterned garden glove planting another at the right side of the frame, with green grass.
Photo by Matt Suwak.

In addition, it may destroy essential mycorrhizal-forming fungi, and soil’s ability to take up vital nutrients like iron.

The Master Gardener Garden Notes of the Colorado State University Extension on organic fertilizers state, “phosphorus from bone meal is only available to plants in soils that have a pH below 7.0.” If your soil pH is above 7.0, or on the alkaline side of neutral, the phosphorus in this type of organic fertilizer is unavailable for uptake by plant roots.

Before applying this product to your garden, always have the soil tested to determine nutrient needs and current pH levels.

If testing confirms a P deficiency, you may be directed to apply 10 pounds of bone meal for every 100 square feet of garden soil. Follow the instructions on the package for application.

A small gray and white dog inspects a bed of loose soil with a sneakered foot to the left and a pile of brown flower bulbs at the bottom of the frame, and an evergreen plant at the right.
Photo by Matt Suwak.

Over a period of about four months, soil microbes digest the organic fertilizer, creating food for plants. One application per growing season is all you need.

Fertilizer products vary and may be compared by their N-P-K, or nitrogen-phosphorus-potassium, ratios. Per the above-referenced pros at Colorado State, 3-15-0 is a typical formula suitable for boosting phosphorus.

The (Potentially) Darker Side

If you think this type of organic fertilizer is appropriate for your garden, consider the following three topics currently trending on the subject before purchasing a product:

1. Consider Pet and Child Safety

This organic fertilizer is generally marketed as safe for people and pets, but it has a level of potential toxicity that may cause serious gastrointestinal illness if ingested.

Per the ASPCA, calls about pets eating lawn and garden products such as bone meal fertilizer were among the top 10 reasons for calls to animal poison control in 2017.

Vertical image of a dog with his ears back, next to a plastic bag of organic bone meal fertilizer, a pile of flower bulbs, and a garden spade with a green and yellow handle, on a gravel driveway with green lawn, an evergreen tree, and a house in the background.
Photo by Matt Suwak.

Be sure to blend it well into the soil, and secure unused quantities where they are safe and out of reach.

2. Beware of Runoff

Phosphorus-containing fertilizers raise a red flag because their runoff may cause algae blooms that threaten ecosystems.

This occurs with water-soluble phosphorus products, and is not likely to happen with powdered or granulated bone meal, which does not leach and is the least likely culprit in such situations.

If you’re buying the correct product, this generally isn’t something that you need to worry about.

3. Avoid Potential for Contamination

There is some concern that animal byproducts may be contaminated with bovine spongiform encephalopathy, aka BSE, or mad cow disease.

According to a Bovine Spongiform Encephalopathy (BSE) Questions and Answers document provided by the FDA, contaminated feed may have been a contributing factor to the outbreak of the disease in Britain in 1993.

Vertical closeup image of bone meal fertilizer.
A closer look.

However, the USDA Animal and Plant Health Inspection Service states: “Regulations from the Food and Drug Administration (FDA) have prohibited the inclusion of mammalian protein in feed for cattle and other ruminants since 1997 and have also prohibited high risk tissue materials in all animal feed since 2009.”

There is no mention of concerns over the use of bone meal fertilizer, however, the purchase of American-made products may be the best choice for both feed and fertilizer, in terms of safety.

Where to Buy

OMRI (Organic Materials Review Institute) listed for organic use, Espoma Organic Bone Meal is available via Amazon.

Espoma Organic Bone Meal, 4 lbs., available via Amazon

Available from a brand that many gardeners trust, it’s made with organic ingredients in a 4-12-0 mix of bone meal to promote strong roots and flowers.

For another organic, American-made product, try Down to Earth Bone Meal. This product is available on Amazon in 5-pound packages.

Down to Earth Bone Meal, 5 lbs.

For extra peace of mind, it is labeled “People & Pet Safe When Used As Directed.”

Burpee’s Natural & Organic Bone Meal is another recommended option, OMRI labeled for organic use, with a 6-8-0 mix.

A white and pink plastic bag of Burpee bone meal fertilizer, isolated on a white background.

Burpee Natural & Organic Bone Meal

This product is available from Burpee in 3-pound bags.

Application Tips

When applying any sort of fertilizer, moderation is key. Too much fertilizer can injure plants, and much of the excess will be washed away and become a waste.

Our writer Matt Suwak provided the following directions:

Step 1 – Dig

First, dig out the area where you’ll be planting your bulbs.

Closeup of a gray sweater sleeve and a hand wearing a light green glove with a purple, pink, yellow, and orange flower pattern, pressing a brown flower bulb into light brown earth that has been loosened.
Photo by Matt Suwak.

We used a small sprinkling of bone meal at the bottom of the planting area, added a thin sprinkling of soil, then plopped the bulbs into place.

Step 2 – Cover

Cover the bulbs with loose earth, then apply a light sprinkling of bone meal to the surface.

An arm wearing a gray sleeve and a hand clothed in a green glove with pink, orange, and purple flowers holds a garden spade with a yellow and green handle and spreads soil over newly planted bulbs, with grass to the left of the frame.
Photo by Matt Suwak.

The package that we were working with recommends 1 tablespoon per square foot, or 1 cup per 20 square feet, and this recommended ratio is relatively standard.

I’ve never been one for this kind of specificity, so instead I lightly sprinkled the fertilizer on top of the soil.

Step 3 – Rake

Rake the fertilizer into the soil to prevent it from being washed away, or gobbled up by critters.

Closeup closely cropped shot of a metal and plastic rake working bone meal into loose soil, with grass to the right and an evergreen shrub to the left.
Photo by Matt Suwak.

If you’re applying mulch to the planting area, this is when to do it.

Step 4 – Water

Water in the bone meal. This is an important step, and should not be ignored unless rain is definite in the next 24 hours!

Every two months, apply a lightly sprinkled application to the planting area. You don’t need to rake in these additional layers, but watering the fertilizer in is necessary.

Start with the Soil

Remember, there are a lot of garden products from which to choose. Don’t be swayed by colorful pictures of happy plants when it’s the soil you need to be thinking about.

A light green plastic bag of MiracleGro organic bone meal to the left of a pile of brown flower bulbs and a garden knife with an orange handle, in loose brown soil, with an evergreen in the background.
Photo by Matt Suwak.

Adding bone meal where phosphorus is deficient gives a jump start to plants like vegetable seedlings and bulb flowers. It fosters strong cell growth, sturdy root stock, and prolific flowering and fruiting.

Used as indicated by a soil test, it may be just what your garden needs!

For further reading, consult Gardener’s Path for articles on:

Tell us how your garden grows in the comments section below, and feel free to leave your questions below!

Photos by Matt Suwak © Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Product photos via Burpee, Espoma, and Down to Earth. Uncredited photos via Shutterstock. With additional writing and editing by Matt Suwak and Allison Sidhu.

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About

Nan Schiller is a writer with deep roots in the soil of southeastern Pennsylvania. Her background includes landscape and floral design, a BS in business from Villanova University, and a Certificate of Merit in floral design from Longwood Gardens. An advocate of organic gardening with native plants, she’s always got dirt under her nails and freckles on her nose. With wit and hopefully some wisdom, she shares what she’s learned and is always ready to dig into a new project!
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Shon
Shon (@guest_4711)
4 years ago

All the other blogs I’ve read about bone meal say don’t use it if your soil PH is above 7.0, but you say don’t use it if below 7. Why?

Betty Chin
Betty Chin (@guest_6177)
3 years ago

What do you think of blood meal for fertilizer?

dani
dani (@guest_10954)
3 years ago

I just like to share my experience with bone meal. In farming it enables me to grow more in less time.

Last edited 3 years ago by dani
Tania
Tania (@guest_17556)
1 year ago

What about trying to make homemade bone meal by first making a long-cooked bone broth from animal carcasses/bones and then pulverizing the leftover bones? Have you ever heard of anyone doing that and seeing success with it?