Chicken manure is a highly concentrated organic fertilizer that can be exceptionally beneficial for growing tomatoes, provided it is handled correctly. Raw manure is too potent for direct garden use, but when properly processed, it becomes a nutrient-rich soil amendment. Tomatoes are heavy feeders that respond well to the balanced nutrition and organic matter that prepared chicken manure supplies. Using this fertilizer requires focusing on safety and timing to ensure plant health and maximum fruit production.
The Nutritional Advantage for Tomato Growth
Chicken manure offers a powerhouse of nutrients, often containing twice the nitrogen concentration compared to other common livestock manures like cow or horse. This high nitrogen content is particularly beneficial for the vegetative growth phase of the tomato plant, supporting the development of strong stems and lush, green foliage early in the season. Nitrogen is a primary component of chlorophyll and amino acids, driving overall plant structure and energy production.
Chicken manure delivers significant levels of phosphorus and potassium, the two other macronutrients that tomatoes require in abundance. Phosphorus supports robust root development, which is critical for anchoring a heavy fruit load, and aids in flowering and fruit set. Potassium is linked to overall plant health, disease resistance, and the quality, flavor, and size of the tomato fruit.
The manure is also a source of secondary nutrients, including high concentrations of calcium, which is important for tomatoes to prevent blossom end rot. Magnesium and sulfur are also present, contributing to enzyme function and protein synthesis within the plant. When incorporated into the soil, this material acts as an organic amendment, enhancing the soil’s structure, water retention, and microbial diversity.
Essential Preparation: Converting Raw Manure to Safe Fertilizer
Raw chicken manure is often referred to as “hot” because its high concentration of nitrogen, primarily uric acid, can rapidly convert to ammonia gas. Applying this fresh material directly causes “fertilizer burn,” where the high nitrogen and salt content draws moisture out of the plant roots, dehydrating and damaging the tissue. This raw form also carries a risk of human pathogens, such as Salmonella and E. coli, which can contaminate edible crops.
The process of composting or aging is mandatory to stabilize the nutrients and eliminate these risks. Composting involves mixing the manure with carbon-rich materials, like straw or dry leaves, to achieve an ideal carbon-to-nitrogen ratio. This mixture must be managed to reach and maintain a core temperature between 131°F and 170°F for several days.
Reaching these temperatures is necessary to kill harmful pathogens and weed seeds, effectively sanitizing the product. For true composting, this high-heat phase should be followed by a curing period, usually lasting several months, during which the material breaks down into a dark, crumbly final product. If hot composting is not feasible, the manure must be aged for a minimum of four to six months, though aging is less effective at eliminating pathogens and weed seeds than proper hot composting.
Specific Application Methods for Tomato Plants
The most effective method for using prepared chicken manure is to incorporate it into the soil before planting the tomato seedlings. This pre-planting application allows stabilized nutrients to be evenly distributed throughout the root zone, providing a slow-release food source for the entire growing season. For garden beds, mix 20 to 30 pounds of well-composted chicken manure into every 100 square feet of soil, working it into the top six to eight inches.
For raised beds, a layer of one to two inches of finished composted manure can be spread over the surface and lightly worked into the existing soil before transplanting. Complete this incorporation several weeks before planting to ensure any remaining volatile compounds dissipate and soil microbes begin the nutrient release process. This initial application provides the nitrogen needed for strong early growth.
As the tomato plants begin to flower and set fruit, a side-dressing application can replenish nutrients. This involves applying a small amount of the composted manure in a ring around the plant, keeping it a few inches away from the main stem to prevent root damage. The manure should be lightly scratched into the soil surface and immediately watered in, which helps move soluble nutrients down to the feeder roots. Alternatively, a “manure tea” can be made by steeping the composted material in water and applied as a liquid feed throughout the season for a more immediate nutrient boost.