Bone meal is exactly what it sounds like: bones that have been finely ground into dust. Typically, the bones are a by-product of the beef industry. Once they're ground up, the bones undergo a sterilization process that eliminates potential bacteria and microbes and increases nutrient availability. The result is bone meal fertilizer.
So why is it so good for the garden? The minerals in bone meal are primarily made up of phosphorous, which is a macronutrient all plants need, though, in different concentrations. It also contains calcium and other nutrients that can help your plants thrive.
Since bone meal fertilizer contains nutrients that your plants require, it can be a smart way to feed your garden. Before you start buying the stuff by the pound, it's important to note that it has its drawbacks. Read on to find out how to make the most of bone meal and what to avoid when using this common garden additive.
How Bone Meal Helps Plants
If you perform a soil test and notice that you’re soil is lacking phosphorous, bone meal is a targeted way to increase the availability of this nutrient in the earth without unnecessarily adding other nutrients in the process.
Bone meal also has traces of calcium, which is an important micronutrient for plant health. Calcium helps reduce instances of diseases (e.g., blossom end rot) and increases healthy root development.
You’ll also find trace amounts of other nutrients in bone meal including nitrogen and potassium, but the amounts are negligible.
What Are the Benefits of Bone Meal Fertilizer?
Bone meal is an organic fertilizer, so even organic gardeners can use it. What's especially nice about it is that it’s a targeted way to increase the amount of phosphorous available in your garden soil and balance out high-nitrogen fertilizers.
It's also easy to mix into the soil and you won't have a hard time finding it at your local hardware store or nursery. On top of that, bone meal is a slow-release fertilizer, so there's no need to worry about stressing your plants with a sudden introduction of concentrated nutrients.
What are the Drawbacks of Using Bone Meal Fertilizer?
The main drawback of this type of fertilizer is the fact that it’s in a form that’s easy to ingest, so you should be careful when you apply it to avoid inhaling it. Another drawback is its source. Some gardeners prefer to avoid animal-derived fertilizers. Vegetarians and vegans, for instance, may want to steer clear of bone meal as a fertilizer.
Bone meal was once as a supplement for some animals, though it's banned in the EU in animal feed. That's because there is some concern that it could spread Bovine Spongiform Encephalopathy (BSE).
While it’s largely impossible to contract bovine diseases via bone meal dust, it’s still a good idea to use a mask when applying it to your garden plants. Why? The fine powder can end up in your lungs if you inhale it and may exacerbate allergies or other respiratory conditions.
Another downside is that if you add bone meal to soil with the wrong pH, you may be wasting your time, money, and effort. Plants won’t can't access the nutrient in bone meal if the pH is above 7.
Too much bone meal also causes problems. If you add it when it’s not needed or put it in soil with the wrong pH, you can contaminate the soil. In excess, phosphorous also slows root development. On top of that, adding unnecessary phosphorous can lead to environmental harm and is a complete waste of money.
Another problem is that bone meal is an attractant for carnivorous creatures. Meat-loving animals might find their way into your garden thanks to the lingering scent of bone meal. Don't top-dress with this type of fertilizer if you want to avoid carnivorous intruders.
If you have pets you should be careful when applying bone meal to your garden as it may attract cats and dogs and it may be harmful if they ingest it.
Bone Meal Alternatives
If bone meal seems like an unappealing way to top up phosphorous stores for your plants, consider rock phosphate or manure as a substitute. You can also use vegetable-based fertilizers like soybean meal. Soybean meal has a similar make-up as bone meal, with an NPK ratio of 7-2-1.
How To Use Bone Meal in the Garden
Always test your soil before adding fertilizer to identify whether there’s a problem in the first place. Adding any type of fertilizer to your garden without checking your soil’s nutrient makeup can cause nutrient imbalances and other issues. Be sure to check the pH of your soil, as well. The wrong pH can limit plant uptake of certain nutrients.
You may notice that your plants are weak and stunted and assume you know what the issue is. While this is a potential sign of phosphorous deficiency, a soil test is the only way to know for sure.
Once you've conducted your test and you're sure the soil is deficient, it's time to add some bone meal. You can apply it in one of two ways.
The first way is to sprinkle about a half cup of bone meal into the hole when transplanting a plant. Work it into the existing soil a little before putting your new garden addition in place. Water your plant thoroughly to work the bone meal into the soil.
The second way is to sprinkle it over the soil. The typical application rate is 10 pounds per 100 square feet of soil. Be sure to work it into the soil a little and then water thoroughly. Since bone meal is a slow-release fertilizer, you don't need to re-apply throughout the year. Once is good enough.
You can apply many fertilizers as a top-dressing in the garden. A sprinkling around the base of your plants is the typical procedure for applying most fertilizers. However, bone meal should not be applied in the same fashion. The reason? It attracts carnivorous animals. Bone meal is best mixed into the soil rather than spread on top of it. Thoroughly incorporating it in your soil mix is the best way to avoid attracting unwanted critters into your yard and garden.
Is Bone Meal the Same Thing As Blood Meal?
While both are by-products of the meat industry, the two are not the same. Blood meal is mainly composed of Nitrogen and is better as a fertilizer in soils that are nitrogen deficient. Blood meal is also capable of lowering pH in soils that are too alkaline. Take care when applying this type of fertilizer as it may stress or burn young plants.
Making Bone Meal at Home
It's cheaper to make your own bone meal at home, but it's definitely a long process. You'll need to weigh the pros and cons of making it yourself with the convenience of purchasing it at the store.
You can save money and avoid creating excess waste by making your own bone meal fertilizer right at home. You'll need a sufficient amount of animal bones to get started, so start by collecting bones in a sealed container in the freezer until you've gathered a good amount.
Once you've collected enough bones, you'll need to clean and sterilize them. Bake bones in the oven at 400°F for an hour until they get brittle. Remove them and scrape off any remaining meat and fat. Then boil the bones in water for up to 8 hours.
Now you need to wait for the bones to dry before you can grind them up into dust. This is where you need a bit of patience. The process of drying may take several weeks.
After the bones have thoroughly dried out, it's time to crush your bone collection. There are lots of ways to go about crushing the bones. You can put them in a heavy-duty plastic bag and roll over the bones with a rolling pin. Or you can crush them in a mortar and pestle. Once you crush the bones, toss them in a food processor or blender to grind them down to a fine dust.
Now you can use the bone dust in your garden as a fertilizer. Let us know how it goes!