The common bush bean, Phaseolus vulgaris, is a popular choice for home gardeners due to its compact size and straightforward growing needs. Intensive gardening, often called square foot gardening (SFG), maximizes production by planting crops much closer together than traditional row methods. Understanding the specific planting density for bush beans is fundamental to success in these small, highly productive spaces.
Determining the Ideal Planting Density
The recommended density for bush beans within the intensive gardening model is nine plants per square foot. This high density is possible because bush bean varieties have a determinate growth habit. They grow to a predetermined height, typically one to two feet, before ceasing vertical growth and focusing energy on producing pods. Unlike indeterminate pole beans, bush beans form a compact, self-supporting shrub.
To achieve this density, plant nine seeds in a precise three-by-three grid within the 12-inch by 12-inch square. This arrangement places each seed approximately four inches from its nearest neighbor. Although some gardeners use a lower density (four to six plants) to improve airflow, nine remains the standard for maximum space efficiency. The compact nature of the bush bean tolerates this close proximity, provided other growing conditions are optimized.
Soil Preparation and Water Management for Intensive Planting
Achieving a successful harvest at a high density requires specialized attention to the growing medium and its maintenance. Because the plants are packed so closely, they quickly deplete standard garden soil of nutrients and moisture. The planting bed must be deep, with a minimum depth of six to eight inches, to accommodate the concentrated root mass.
The soil should be highly fertile, loose, and well-draining, often achieved through a mixture of compost, peat moss or coir, and coarse vermiculite. This structure promotes aeration for healthy root development while providing necessary water retention for the dense population. Bush beans are sensitive to drought stress, so consistent moisture is required to sustain continuous pod production.
The increased competition for resources means that a regular watering schedule is paramount, often necessitating deep watering more frequently than in a traditional garden. While beans fix atmospheric nitrogen into the soil, the sheer number of plants per square foot still benefits from a balanced, low-nitrogen side-dressing of fertilizer during the growing season. Too much nitrogen, however, promotes excessive foliage growth at the expense of pod development.
Expected Yield and Harvesting Techniques
The payoff for intensive planting is a remarkably high yield from a small footprint. A healthy crop of nine bush bean plants in a single square foot can realistically produce between one and two pounds of fresh beans over the entire harvest period. This output depends heavily on the specific variety grown and the consistency of care, especially water and nutrient availability.
Bush beans are typically determinate, producing the bulk of their pods in a single, concentrated flush, usually ready for harvest 50 to 60 days after planting. To encourage continued production beyond the main harvest, employ successive harvesting. This involves picking the pods frequently, ideally every two to three days, as soon as they reach edible size.
When harvesting from a dense square, gently part the thick foliage to locate pods hidden near the center of the plant. Frequent picking prevents the pods from maturing fully, which stimulates the production of new blossoms and a subsequent, albeit smaller, second crop. Once the plants are exhausted, the square can be cleared and immediately replanted with new seeds for a continuous supply throughout the season, a technique called succession planting.