Is Blood Meal Good for Tomato Plants? Expert Guide

By Emma Thompson · May 12, 2025

Blood meal is good for tomato plants when used correctly, providing a rich source of nitrogen that promotes vigorous leafy growth and supports early plant development. However, overuse can lead to nutrient imbalances, pH fluctuations, and delayed fruiting, so proper application rates and timing are essential.

What Is Blood Meal and How Does It Benefit Tomato Plants?

Blood meal is an organic fertilizer made from dried animal blood, typically a byproduct of slaughterhouses. It's processed into a powder or granular form and used in gardens to boost soil nitrogen levels. For tomato plants, which require varying nutrient ratios throughout their lifecycle, blood meal can be a powerful tool—especially during the vegetative stage.

Key Benefits of Blood Meal for Tomatoes

High Nitrogen Content: Blood meal contains approximately 12-14% nitrogen, making it one of the richest organic sources available.
Organic and Fast-Acting: Unlike some slow-release fertilizers, blood meal becomes available to plants within 1–2 weeks after application.
Promotes Leafy Growth: Supports strong stem and foliage development in young tomato plants.
Improves Soil Fertility: Enhances microbial activity in the soil due to its high protein content.

When and How to Use Blood Meal on Tomato Plants

Timing and dosage are critical when applying blood meal. Applying it at the wrong growth stage can hinder fruit production.

Best Practices for Application

Apply at Planting Time: Mix 1–2 tablespoons per planting hole to support early root and leaf development.
Use During Vegetative Stage: Apply every 4–6 weeks while the plant is focusing on leaf and stem growth.
Avoid Late-Season Use: Stop using blood meal once flowering begins to prevent excessive foliage at the expense of fruit.
Water Thoroughly After Application: Prevents root burn and helps nutrients dissolve into the soil.

Potential Drawbacks of Blood Meal for Tomatoes

Despite its benefits, blood meal has several limitations and risks that gardeners should consider.

Common Issues with Blood Meal Use

Nitrogen Burn: Over-application can cause yellowing or browning of leaves due to excess nitrogen.
pH Imbalance: Blood meal can lower soil pH temporarily, making it more acidic.
Attracts Animals: The smell may attract dogs, raccoons, or other scavengers to your garden.
Limited Phosphorus and Potassium: Does not supply adequate P or K, which are crucial during flowering and fruiting.

Fertilizer Type	Nitrogen (N%)	Phosphorus (P%)	Potassium (K%)	Solubility Rate	Release Time
Blood Meal	12–14%	0.5–1%	0.5–1%	High	1–2 weeks
Bone Meal	3–4%	15–20%	0%	Low	3–6 months
Compost	1–3%	0.5–1.5%	1–2%	Medium	2–8 weeks
Tomato-Specific Fertilizer	5–8%	10–15%	10–15%	High	1–2 weeks

Table data source:1, 2

The table shows that blood meal excels in nitrogen content and solubility but lacks balanced phosphorus and potassium, which are vital for fruit development in tomatoes. Compared to specialized tomato fertilizers, it’s better suited for early growth rather than full-cycle nutrition.

Alternatives to Blood Meal for Tomato Fertilization

While blood meal is effective for nitrogen supplementation, other organic options offer more balanced nutrition for tomatoes throughout their lifecycle.

Compost: Provides slow-release nutrients and improves soil structure.
Fish Emulsion: Offers a balanced N-P-K ratio and is fast-acting, ideal for weekly feeding.
Cottonseed Meal: Contains moderate nitrogen and slightly acidic, suitable for long-term use.
Worm Castings: Gentle, nutrient-rich, and improve microbial health without risk of burn.

Frequently Asked Questions About Blood Meal and Tomato Plants

Can I use blood meal on tomato plants during flowering?

No, it's best to avoid blood meal once tomato plants begin flowering. High nitrogen encourages leafy growth at the expense of fruit set. Switch to a low-nitrogen, high-phosphorus fertilizer like bone meal during this stage.

How much blood meal should I use per tomato plant?

Use 1–2 tablespoons of blood meal per plant when transplanting or during early vegetative growth. Mix it into the soil and water well to prevent root burn. Do not exceed recommended amounts.

Is blood meal safe for organic gardening?

Yes, blood meal is approved for organic gardening by organizations such as the USDA National Organic Program, provided it's sourced from certified organic animals and processed without synthetic additives.

Does blood meal raise or lower soil pH?

Blood meal can temporarily lower soil pH (make it more acidic) as it breaks down and releases ammonium. Monitor pH regularly and adjust with lime if necessary, especially in already acidic soils.

Can blood meal harm pets or wildlife?

Yes, the scent of blood meal may attract dogs, cats, or wild animals to dig in garden beds. Store securely and consider using deterrents or alternative fertilizers if pests are a concern.