Using blood and bone fertilizer at a rate of about one handful per square meter works well for most garden plants. But figuring out exactly how much blood and bone to use can feel tricky because different plants have different needs. This guide breaks it down simply so you get the dosage right every time.
Blood and bone is a natural, slow-release fertilizer made from animal by-products. It provides nitrogen for leafy growth and phosphorus for strong roots and flowers. Too little won’t help your plants, but too much can burn them or upset soil balance.
Let’s start with the basics. A standard handful is roughly 50 to 70 grams. For general garden beds, spread one handful per square meter and rake it into the topsoil. For pots and containers, use about one tablespoon per 10 liters of potting mix.
General Guidelines For Blood And Bone Application
Before we get into specific plants, here are the universal rules. Always apply blood and bone to moist soil, then water it in well. This helps the nutrients start breaking down and prevents nitrogen from escaping into the air.
Apply it every 6 to 8 weeks during the growing season. In winter, most plants go dormant and don’t need extra feeding. Overfeeding can cause soft, leggy growth that attracts pests.
- For new garden beds: 100 grams per square meter mixed into the top 10 cm of soil
- For established beds: 70 grams per square meter as a top dressing
- For lawns: 50 grams per square meter, watered in thoroughly
- For fruit trees: 200 grams per tree, spread around the drip line
How Much Blood And Bone To Use For Vegetables
Vegetables are hungry plants, especially leafy greens and fruiting crops. They need a steady supply of nitrogen and phosphorus to produce well. Here’s the breakdown for common veggie groups.
Leafy Greens Like Lettuce, Spinach, And Kale
These plants love nitrogen for lush leaves. Apply 60 grams per square meter before planting. Then side-dress with another 30 grams per square meter every 4 weeks during growth.
Don’t overdo it though. Too much nitrogen can make leaves bitter and encourage fungal diseases. Stick to the schedule and watch your plants respond.
Root Vegetables Like Carrots, Beets, And Potatoes
Root crops need more phosphorus for strong root development. Use 80 grams per square meter worked into the soil before sowing. Avoid high nitrogen after planting, as it can cause forked or hairy roots.
For potatoes, apply half the dose at planting and half when the plants are about 15 cm tall. This gives them a steady supply without overloading the soil.
Fruiting Vegetables Like Tomatoes, Peppers, And Cucumbers
These heavy feeders benefit from 100 grams per square meter at planting time. Then give them a boost of 50 grams per square meter when the first flowers appear. This supports fruit set and development.
Be careful not to apply too close to the stem. Spread the fertilizer around the root zone, about 10 cm away from the plant base. This prevents root burn and encourages deep root growth.
How Much Blood And Bone To Use For Flowers
Flowering plants need phosphorus to produce blooms. Blood and bone provides this in a slow-release form that won’t burn delicate roots. Here’s how to dose different types of flowers.
Annual Flowers Like Petunias, Marigolds, And Zinnias
For annual bedding plants, use 50 grams per square meter mixed into the soil before planting. Then apply 30 grams per square meter every 6 weeks during the blooming period. This keeps flowers coming all season.
If you’re planting in pots, use one teaspoon per 5 liters of potting mix. Mix it in thoroughly before adding plants. Liquid feed can supplement if needed, but blood and bone provides the base nutrition.
Perennial Flowers Like Roses, Lavender, And Peonies
Perennials benefit from a spring feeding of 70 grams per square meter. For established roses, apply 100 grams per plant in early spring and again after the first flush of blooms. This encourages repeat flowering.
For lavender and other Mediterranean plants, use half the dose. These plants prefer lean soil and too much fertilizer can reduce their essential oil content. A light sprinkle in spring is enough.
How Much Blood And Bone To Use For Trees And Shrubs
Trees and shrubs have larger root systems and need more fertilizer, but spread over a wider area. The key is to apply it evenly around the root zone, not just at the trunk.
Fruit Trees Like Apples, Citrus, And Stone Fruits
For young fruit trees, use 100 grams per tree in spring and again in early summer. For mature trees, increase to 200 grams per application. Spread it in a circle under the canopy, starting 30 cm from the trunk and extending to the drip line.
Water it in well after application. This helps the nutrients reach the feeder roots at the edge of the root zone. Avoid applying when the soil is bone dry, as this can cause root burn.
Ornamental Shrubs Like Camellias, Azaleas, And Hydrangeas
Acid-loving shrubs like camellias and azaleas need less blood and bone. Use 50 grams per square meter in spring. Too much can raise soil pH and cause yellowing leaves. For hydrangeas, the same dose works well to support flower production.
For evergreen shrubs, apply 70 grams per square meter in early spring. This gives them a slow-release nitrogen boost for new growth. Don’t feed after mid-summer, as this can encourage tender growth that frost damages.
How Much Blood And Bone To Use For Lawns
Lawns benefit from blood and bone for a natural green-up without chemical runoff. The application rate depends on your grass type and the season.
For warm-season grasses like Bermuda and buffalo, use 50 grams per square meter in spring and again in early autumn. For cool-season grasses like fescue and ryegrass, apply 60 grams per square meter in spring and autumn.
- Measure your lawn area in square meters
- Weigh out the correct amount of blood and bone
- Spread it evenly using a broadcast spreader or by hand
- Water the lawn thoroughly to wash the fertilizer into the soil
- Keep pets and children off the lawn for 24 hours
Don’t apply blood and bone to lawns during drought or extreme heat. The nitrogen can burn the grass blades. Wait for a cooler day or water the lawn well beforehand.
How Much Blood And Bone To Use For Potted Plants
Potted plants have limited soil volume, so you need to be more precise. Too much fertilizer can build up salts and damage roots. Here’s a simple guide.
- Small pots (10-15 cm): 1 teaspoon per pot
- Medium pots (20-25 cm): 1 tablespoon per pot
- Large pots (30-40 cm): 2 tablespoons per pot
- Very large pots (50 cm+): 3-4 tablespoons per pot
Mix the blood and bone into the top 2-3 cm of potting mix. Water it in immediately. Repeat every 6 to 8 weeks during the growing season. In winter, stop feeding completely for most houseplants.
For succulents and cacti, use half the recommended dose. These plants are adapted to low-nutrient conditions and can rot if overfed. A light sprinkle once in spring is usually enough.
Factors That Affect How Much Blood And Bone To Use
Not all gardens are the same. Several factors can change the ideal dosage for your specific situation. Here’s what to consider.
Soil Type And Quality
Sandy soils drain quickly and lose nutrients faster. You may need to apply blood and bone more frequently, but at lower doses. Clay soils hold nutrients longer, so you can use slightly less and extend the interval between feedings.
If you have rich, organic soil, you might only need half the recommended dose. A soil test can tell you your nutrient levels. Many garden centers offer simple test kits for nitrogen and phosphorus.
Plant Age And Size
Young seedlings and transplants need less fertilizer than mature plants. Start with half the recommended dose for the first month. As plants grow, increase to the full amount. Overfeeding young plants can cause leggy growth and weak stems.
For very large, established plants like old fruit trees, you can double the dose. Spread it over a wider area to match the expanded root system. Always water in well after application.
Climate And Season
In warm, wet climates, blood and bone breaks down faster. You might need to apply every 4 to 6 weeks instead of 8. In cool, dry climates, the fertilizer lasts longer and you can stretch the interval to 10 weeks.
During active growth periods in spring and summer, plants need more food. In autumn, reduce the dose by half as growth slows. Stop feeding completely in winter for most outdoor plants.
Common Mistakes When Using Blood And Bone
Even experienced gardeners can get it wrong sometimes. Here are the most common errors and how to avoid them.
- Applying to dry soil: Always moisten the soil first to prevent root burn
- Using too much: More is not better. Stick to the recommended rates
- Forgetting to water in: Nutrients can escape as gas if not watered in
- Applying too close to stems: Keep fertilizer 10 cm away from plant bases
- Storing improperly: Keep blood and bone in a sealed container away from pets
If you accidentally overapply, water the area deeply to flush excess nutrients. This helps prevent root damage and salt buildup. Watch for signs of overfeeding like yellowing leaf tips or wilting despite moist soil.
How To Apply Blood And Bone Correctly
Getting the application method right is just as important as the dose. Follow these steps for best results.
- Wear gloves and a mask to avoid inhaling dust
- Measure the correct amount for your area or plant
- For garden beds, sprinkle evenly over the soil surface
- Rake it lightly into the top 2-3 cm of soil
- Water thoroughly with a gentle spray
- For pots, mix into the top layer of potting mix
- Water immediately after application
For liquid application, you can dissolve blood and bone in water. Use 1 tablespoon per 5 liters of water. Stir well and let it sit for an hour. Then water your plants as usual. This method works faster but needs more frequent application.
Frequently Asked Questions
Can I use blood and bone on all plants?
Most plants benefit from blood and bone, but acid-loving plants like blueberries and rhododendrons prefer specialized fertilizers. Also avoid using it on plants that need low nitrogen, like native Australian plants.
How often should I apply blood and bone?
Every 6 to 8 weeks during the growing season is standard. For heavy feeders like tomatoes and roses, you can apply every 4 weeks. Reduce frequency in cool weather.
Is blood and bone safe for pets?
Blood and bone can attract dogs and other animals because of its smell. Keep it stored securely. If your pet eats a large amount, contact your vet. Water the fertilizer in well to reduce odor.
Can I mix blood and bone with other fertilizers?
Yes, you can combine it with potash or compost for a more balanced feed. Avoid mixing with high-nitrogen chemical fertilizers, as this can cause nutrient overload.
Does blood and bone expire?
It doesn’t spoil, but it loses potency over time. Use it within 12 months of purchase for best results. Store it in a cool, dry place in a sealed container.
Final Tips For Using Blood And Bone
Start with less than you think you need. You can always add more later, but you can’t take it back. Observe your plants after feeding. Dark green leaves and steady growth mean you’re on the right track.
If leaves turn yellow or growth slows, you might need to increase the dose slightly. But if leaves look scorched or plants wilt, you’ve used too much. Flush the soil with water and wait a few weeks before feeding again.
Blood and bone is a fantastic natural fertilizer when used correctly. It feeds your plants slowly, builds soil health, and reduces the need for chemical inputs. With the guidelines in this article, you now know exactly how much to use for every part of your garden.
Remember the golden rule: one handful per square meter for most plants. Adjust up or down based on plant type, soil condition, and season. Your garden will thank you with vigorous growth and abundant blooms or harvests.