A mulberry tree (Morus species) is a hardy, fast-growing deciduous plant that offers an abundant fruit harvest, making it a popular addition for home gardeners. These trees are known for their resilience and ability to thrive across a wide range of climates. Mulberry cultivation has a significant history, particularly with the white mulberry, Morus alba, which was cultivated extensively as the primary food source for silkworms. Growing this tree provides a yield of sweet, soft berries with relatively little effort once the tree is established.
Selecting the Right Location and Variety
A mulberry tree performs best in a location that receives full sunlight for at least six to eight hours each day, which maximizes fruit production. While the tree can tolerate partial shade, insufficient light will lead to a poor harvest. The tree is adaptable to various soil types, including sandy and clay soils, but it thrives in well-drained, fertile soil that prevents waterlogging. Mulberries prefer a slightly acidic to neutral soil pH, ideally ranging between 5.5 and 7.0.
Choosing the right species is important, as the three main types—white (M. alba), red (M. rubra), and black (M. nigra)—have different hardiness and fruit characteristics. White mulberries are the most cold-tolerant, while black mulberries have the most intensely flavored fruit but are limited to warmer zones. Dwarf or weeping varieties are excellent options for gardeners with limited space, as they can be maintained at a much smaller size than standard trees, which can reach heights of 30 to 80 feet.
Planting and Initial Care
Planting is best done in the early spring while the tree is still dormant, particularly if using a bare-root specimen. For a container-grown tree, planting is possible through early summer, though it may experience some leaf drop due to transplanting stress. The planting hole should be dug approximately twice as wide as the root ball and about the same depth.
If planting a container-grown tree, loosen any tightly circling roots to encourage them to grow outward into the native soil. Place the tree in the center of the hole so the root flare is level with the surrounding ground. Backfill with the excavated soil, tamping lightly to remove large air pockets. Immediately after planting, water the tree thoroughly to settle the soil around the roots. Consistent moisture is required during the first growing season to establish a strong root system.
Apply a layer of organic mulch, such as wood chips or compost, around the base to help retain soil moisture and regulate temperature. Keep the mulch several inches away from the trunk itself to prevent moisture buildup that can lead to rot or pest issues.
Essential Maintenance: Pruning and Training
Pruning is necessary for managing the vigorous growth of a mulberry tree, which helps maintain a manageable size and promotes better fruit accessibility. Since mulberries are prone to “bleeding,” or exuding sap from cuts, all major structural pruning should be carried out during the late winter or early spring while the tree is dormant. Dormant pruning focuses on removing dead, diseased, or crossing branches to improve air circulation and light penetration.
Annual dormant pruning is necessary to control the tree’s height and encourage fruit production at a lower level, as the fruit appears on the previous year’s growth. A more aggressive annual pruning regimen is required if the goal is to keep the tree small or facilitate easier harvesting. Cuts larger than two inches in diameter should be avoided, as mulberry wood heals slowly and larger wounds leave the tree vulnerable to disease and pests.
Training methods can be used, such as keeping the tree as a standard central leader or training it into a modified open center shape. Summer pruning involves lightly trimming back long, new growth to control the overall canopy size and shape during the active season.
Harvesting the Fruit and Managing Staining
Mulberries are ready for harvest in late spring through early summer. A berry is ripe when it has fully changed color—typically to a deep red, purple, or black for most varieties—and separates easily from the stem with only a light touch. Unlike many other fruits, mulberries do not ripen after they are picked, so they must be harvested when fully mature.
For collecting a large harvest, lay a clean tarp or sheet on the ground beneath the canopy. Gently shaking the main branches will cause the ripe berries to drop onto the sheet, while unripe fruit remains attached. Mulberries are highly perishable, and their juice causes deep, persistent staining on skin, clothing, concrete, and pavement.
To manage staining, plant the tree away from patios, driveways, and walkways. For red and black-fruited varieties, wearing gloves during harvest is recommended to protect the skin. Promptly cleaning up fallen fruit will prevent fermented odors and reduce the mess.