Mulberry trees (Morus genus) are vigorous, fast-growing fruit producers that yield abundant harvests over a long lifespan. The distance between trees is the most important factor determining long-term health, ease of management, and overall yield. Careful planning is necessary, as incorrect initial spacing can lead to serious issues later.
Key Variables Determining Spacing
The optimal distance between mulberry trees is not a fixed number, but changes based on the grower’s intentions and the specific variety chosen. Spacing is directly influenced by the tree’s ultimate size, which varies significantly between cultivars. Standard varieties, such as Morus rubra or Morus nigra, develop into large, spreading specimens, while dwarf or weeping varieties remain much smaller.
The grower’s pruning strategy also dictates planting distance. A tree allowed to grow naturally requires a vast area, whereas one maintained through heavy annual pruning, like coppicing, can be planted much closer. The ultimate purpose of the planting, whether for an ornamental specimen or a high-yield orchard, determines the necessary space for the canopy and root system.
Standard Spacing for Full-Sized Trees
For the average home grower desiring a large, minimally pruned tree, ample space is required for standard varieties. Full-sized mulberry trees, especially Morus alba and Morus rubra, can reach a height and spread of 25 to 30 feet. Therefore, standard varieties should be planted between 25 and 30 feet apart to ensure their canopies do not overlap.
This wide spacing is essential for maximizing sunlight exposure and allowing proper air circulation throughout the canopy. Sunlight is necessary for flower bud development and fruit ripening, while good airflow is a natural defense against fungal diseases that thrive in damp, stagnant conditions. Crowding trees restricts root development and forces competition for limited soil nutrients and water, which ultimately reduces the yield of each tree.
In contrast, dwarf or compact mulberry varieties require significantly less space, making them suitable for smaller gardens. Cultivars like ‘Gerardi Dwarf’ or certain weeping types should be spaced in the range of 10 to 15 feet apart. This reduced spacing still allows for sufficient individual canopy development and ensures that the tree’s mature size remains manageable for easy harvesting.
Spacing for High-Density and Hedgerow Systems
For commercial or intensive production, mulberry trees are often planted intentionally close together to maximize yield per acre, requiring a commitment to aggressive annual pruning. In a hedgerow system, trees are meant to form a continuous, wall-like barrier rather than distinct, individual specimens. This method typically involves planting trees approximately 5 to 10 feet apart within the row. This close planting necessitates severe, regular pruning to maintain the tree’s shape and size, which keeps the fruit and leaves within easy reach for harvesting.
If the goal is intensive leaf production, such as for silkworm rearing, spacing can be even tighter, with some systems using geometries like 6 by 6 feet or even 8 by 4 feet. Such narrow spacing dramatically increases the number of plants per hectare, compensating for the smaller size and reduced individual yield of each tree. In these high-density systems, the increased competition for light and nutrients is managed through regular, heavy pruning and consistent input of fertilizer and water. For specific pruning techniques like coppicing or pollarding, where the tree is cut back severely each year to encourage new shoot growth, spacing can be as close as 3 to 5 feet apart. This intensive management system prioritizes the production of young, accessible shoots and leaves over the development of a large, individual fruit scaffold.