Blood meal is a popular organic soil amendment for gardeners seeking to boost plant growth naturally. It is a byproduct of the meat processing industry, consisting of dried, powdered animal blood, and is valued for its high nutrient content. Whether it is beneficial for tomato plants depends entirely on the timing and application method, as its concentrated power can be both an asset and a significant risk. This guide provides an overview of blood meal’s composition and explains how to use this product for successful tomato cultivation.
Blood Meal’s Role as a High Nitrogen Source
Blood meal is primarily used as a potent source of nitrogen, often carrying a nutrient ratio of 12-0-0 or higher. This signifies that approximately 12% of the product’s weight is elemental nitrogen, with negligible amounts of phosphorus and potassium. Nitrogen is a macronutrient that is absolutely necessary for the creation of chlorophyll and amino acids, which are the foundational components for plant cell growth.
Applying this amendment promotes robust vegetative growth, resulting in strong, dark green stems and leaves. For tomato plants, focusing on foliage is crucial during early development. A healthy leaf canopy acts as the plant’s solar panel, gathering maximum energy needed to support heavy fruit production later in the season.
The nitrogen in blood meal becomes available to plants relatively quickly compared to many other organic fertilizers. This quick-release characteristic supplies an immediate nutritional boost and continues feeding the plant for several weeks or months. This rapid availability makes it an effective solution for correcting nitrogen deficiencies signaled by yellowing or pale green lower leaves.
Safe Application Rates for Tomato Plants
Blood meal is most beneficial when applied early in the season, aligning with the tomato plant’s need for vigorous structural growth. It should be incorporated into the soil just before or at the time of transplanting young tomato seedlings into the garden. The application should be significantly reduced or stopped entirely once the plant begins to flower, as the focus then shifts to the phosphorus and potassium needed for fruit development.
For individual tomato plants, mix about one to two tablespoons of the product into the soil of the planting hole before setting the plant. Thoroughly mix the powder into the surrounding soil rather than sprinkling it on the surface. This ensures the roots do not come into direct contact with the concentrated powder, which could cause damage.
When side-dressing established plants, carefully work a small amount, such as one teaspoon per plant, into the top inch of soil around the base, avoiding root disturbance. Immediately watering the area after application helps the nitrogen integrate into the soil structure, making it available to the roots and minimizing the risk of burn.
Recognizing and Preventing Nitrogen Overload
The high concentration of nitrogen in blood meal presents the primary risk of nitrogen toxicity, often called “fertilizer burn.” This occurs when the fertilizer’s salt content draws water out of the plant’s roots, dehydrating the tissue. A common symptom is the physical scorching of the leaves, appearing as curled, brown, or yellow tips and margins.
Beyond the physical burn, nitrogen overload causes the tomato plant to remain in a perpetual vegetative state, focusing energy on producing lush, dark green foliage. Gardeners recognize this condition as the “all leaves, no tomatoes” problem, where the plant appears healthy but fails to produce flowers or fruit. The leaves may also develop a characteristic claw-like curl where the tips bend sharply downward.
Prevention involves a few steps to mitigate the risk. Always start with a conservative application rate, using less than the recommended amount until you observe how your soil and plants respond. After every application, deep watering is necessary to dilute the nitrogen salts and move nutrients away from the immediate root zone. Finally, avoid applying blood meal directly against the main stem or on wet foliage, as this increases the chance of localized burn damage.