Alfalfa meal is a popular organic soil amendment and fertilizer derived from the dried and ground leaves and stems of the alfalfa plant, Medicago sativa. This deep-rooted legume provides a steady supply of nutrients and functions as an effective soil conditioner. It improves the physical structure of the soil and enhances microbial life, which helps make stored nutrition available to plant roots.
The Unique Composition of Alfalfa Meal
Alfalfa meal is not a high-potency fertilizer, typically presenting a balanced, low N-P-K ratio, often around 3-1-2 or 3-1-3. Soil microorganisms slowly break down the organic material, releasing nitrogen gradually. This provides a sustained feeding period that matches the plant’s natural uptake rate without the risk of burning plants.
The meal’s value lies in its diverse biological components, particularly the plant growth regulator Triacontanol. This natural compound stimulates root and stem development, leading to more vigorous plant growth. Furthermore, the meal contains a wide spectrum of micronutrients and trace elements, including calcium, magnesium, iron, and various vitamins (A, B, and E) that support overall plant health.
Targeted Plant Groups That Thrive
Alfalfa meal is beneficial for heavy-feeding vegetables that require a steady nutrient supply and overall vigor. Crops like corn, tomatoes, squash, and brassicas (broccoli and cabbage) thrive on the slow-release nitrogen and Triacontanol’s root stimulation. Incorporating the meal into the soil before planting ensures these crops have the foundational nutrition necessary to support their rapid and substantial growth.
Ornamental plants, particularly flowering perennials, respond well to alfalfa meal applications. Roses benefit from the combination of gentle nitrogen for lush foliage and the growth stimulant that encourages repeat and robust blooms. Other flowering shrubs and perennials, including lilacs and peonies, also display enhanced vigor and flower production when the meal is used as a consistent soil conditioner.
The meal’s ability to improve soil structure and stimulate microbial activity makes it valuable for root crops and tubers. Vegetables like garlic, onions, and potatoes benefit from the nutrients and the improved soil environment, which allows for better root and tuber expansion. However, because alfalfa meal is alkaline, it should be avoided for acid-loving plants such as rhododendrons, camellias, and blueberries, which prefer a lower soil pH.
Practical Guide to Application and Timing
There are three primary methods for applying alfalfa meal. The most common method is using it as a soil amendment, where it is broadcast and lightly incorporated into the soil prior to planting. This allows nutrients to become available immediately. For established plants, side dressing is an effective technique. This involves sprinkling the meal around the base of the plant and gently scratching it into the top few inches of soil before watering.
General application rates vary. For larger shrubs like roses, apply approximately two cups of the meal around the base. For vegetable gardens, a medium rate is often around 25 pounds per 1,000 square feet, which can be tilled into the soil. The third method is creating “alfalfa tea” by steeping the meal in water for a few days. This liquid feed provides a more immediate, milder nutritional boost.
Apply alfalfa meal in the early spring, just as plants begin new growth, to ensure slow-release nitrogen is available during the peak growth period. For plants with a long blooming season, a second application can be beneficial, administered about six weeks after the initial spring feeding. Consistent application supports the soil’s biological health and maximizes the long-term benefit of the meal.