Blood meal sounds like something out of a horror movie involving zombies and vampires. But your garden bulbs must be fans of the macabre because they love the stuff.
Give them some blood meal at the right time, and they’ll be growing better than ever.
We link to vendors to help you find relevant products. If you buy from one of our links, we may earn a commission.
No, your bulbs aren’t secretly vampires. They don’t need blood to survive, but they do need certain nutrients, particularly nitrogen, to allow them to maintain stores of the nutrient to support the plant all year long.
Blood meal comes in a powder form that you can apply to the soil to provide your bulbs with the nitrogen they craves.
Coming right up, we’re going to discuss when, why, and how to apply this fertilizer effectively to make your bulbs grow their best. Here’s what’s on the menu:
What Is Blood Meal?
If you’re squeamish maybe skip this section.
Blood meal is dried blood that is made into a powder and sold as a fertilizer. This powder is applied to the soil in order to provide nutrients.
Typically, it comes from leftovers from the livestock and meat-processing production industry.
Instead of discarding the blood that is produced during meat production of animals like chicken, pigs, cattle, and lamb, it is collected and processed by dehydration.
The blood can be dried using chemicals, or it might be heated in a dehydrator, kiln, or oven. It can also be dehydrated through solar drying.
By the way, feather and bone meal are also created out of slaughterhouse waste. Bone meal is a good source of phosphorus and protein, while feather meal provides nitrogen as well.
What Does It Do?
Blood meal is an efficient, bioavailable source of nitrogen for bulbs. It contains 10 to 15 percent nitrogen, plus smaller amounts of iron, phosphorus, and potassium.
It is primarily composed of hemoglobin, which is an iron-containing protein found in red blood cells. In the human body, hemoglobin helps to carry oxygen. In the soil, it adds nutrients that the plant can absorb.
By comparison, feather meal and seabird guano both have 12 percent nitrogen.
Fish powder, another less-commonly used ingredient, has about 13 percent, but it’s expensive to produce, so it’s less popular than the other options.
Any of these ingredients might be added to fertilizers to provide nitrogen to a more complete feed, or they might be used independently.
Benefits
There are a lot of benefits to using this icky-sounding product. Blood meal is acceptable in organic farming practices.
So if you’re growing garlic, lilies, or tulips on an organic farm, don’t worry. Using this fertilizer won’t negate that designation.
It’s water soluble so it can be delivered through the soil and into the roots, making it more available to the bulbs. It also continues feeding for up to six weeks after application.
While it’s not as effective of a deterrent as products formulated specifically for the purpose, blood meal can help to deter deer.
It also increases beneficial microbes like good fungi and bacteria in the soil. You wouldn’t choose this product solely to improve soil microbes or deter deer, but those are an added bonus.
We know that this product helps with bulb growth in particular, thanks to research conducted on plants like onions.
One study, published in the Bangladesh Journal of Scientific and Industrial Research in 2021 noted that the application of blood meal increased bulb yields by over 32 percent in commercial onion farms.
Drawbacks
While blood meal may deter some animals, it can attract others. Raccoons and possums might come looking for that wonderful smell and end up digging up your garden.
The family dog might also be enticed, particularly if you have a Labrador retriever – and consuming it could give Fido some intestinal issues.
There is some evidence to suggest that the nitrogen in blood meal is too readily available to plants and so it isn’t necessarily the best source.
I know that being available sounds like a good thing, and it is, to a certain degree. But when nutrients are too readily available, they may be absorbed too quickly and can cause fertilizer burn or need to be replenished frequently.
It also increases acidity in soil, so if you use it regularly in large amounts, you’ll need to monitor your soil pH and amend it accordingly to keep it within range. This is especially true if you’re growing plants that are sensitive to the wrong pH.
Most gardeners only use this fertilizer once or twice a season when growing bulbs, so the above shouldn’t be too much of a concern.
Where to Buy
Blood meal is generally easy to find at big box stores and garden centers. Many online vendors carry it along with other fertilizers.
Blood Meal
For instance, Arbico Organics carries Down to Earth’s excellent product in eight-ounce, four-, 20-, and 50-pound packages.
How to Apply
For bulbs you plant in the fall that flower in spring, feed them in the fall at planting time.
Those that go in the ground in the spring that will flower either right away or later in the year, fertilize as you plant them.
In other words, the rule of thumb is to apply blood meal at planting time. Don’t add this fertilizer to the hole when planting, always add it to the top of the soil around the plant.
For perennial bulbs that stay in the ground and flower in spring, like tulips and daffodils, feed in the fall before the ground freezes to give them the energy they need to build up the nutrient stores.
You can also add another dose in spring, as the shoots start to appear.
Before you add any food, it’s smart to test your soil. After doing a soil test, you might find that your soil has plenty of potassium and phosphorus, so you don’t need a balanced fertilizer.
You might only need nitrogen, which is just what blood meal is good for.
If after a soil test you find that nitrogen is the only requirement, add a teaspoon for each bulb, on the top of the soil.
You can either mix it with water and then add it to the soil or you can simply sprinkle it on the soil and water it in.
If you also need some phosphorus, add a teaspoon of bone meal. For potassium, add a half teaspoon of langbeinite.
Bigger Better Bulbs
Most bulb plants are nitrogen-hungry, and blood meal is a good source of this nutrient. It’s a match made in heaven!
What kind of bulbs are you growing? Let us know your setup in the comments section below.
Did this guide help you figure out how to put this powerful product to work in your garden? I hope so!
If you’d like some additional information about caring for your flowering bulbs, we have a few other guides that you might be interested in, including:
