White Mulberry: Why This Non-Native Tree Isn’t Worth the Risk
If you’ve been considering planting a white mulberry (Morus alba) in your garden, you might want to think twice. While this deciduous tree might seem appealing with its heart-shaped leaves and sweet berries, it comes with some serious baggage that makes it a poor choice for responsible gardeners.
What Is White Mulberry?
White mulberry is a perennial, multi-stemmed woody plant that typically grows as a shrub but can reach impressive heights of up to 50 feet at maturity. Despite its name, the berries are actually purple in color and quite conspicuous when they ripen. The tree has a rounded shape and moderate growth rate, reaching about 30 feet in 20 years under optimal conditions.
The Problem: It’s Not From Here
Here’s the big issue: white mulberry is completely non-native to North America. Originally from China, this tree has been introduced across the continent and now reproduces spontaneously in the wild without any human help. It’s established itself from coast to coast, thriving in:
- All lower 48 states
- Several Canadian provinces including British Columbia, Ontario, and Quebec
- Hawaii
What’s particularly concerning is that Wisconsin has classified white mulberry as Restricted due to its invasive behavior. This means it’s recognized as a species that can harm native ecosystems.
Growing Conditions (If You Must Know)
White mulberry is frustratingly adaptable, which is part of why it’s become such a successful invader. It tolerates:
- USDA hardiness zones 4-8 (minimum temperature of -18°F)
- Various soil types from coarse to fine textures
- pH levels between 5.0-7.0
- Drought conditions once established
- Both wetland and upland conditions (though it prefers upland areas)
The tree has low fertility requirements, moderate drought tolerance, and can handle partial shade to full sun. It needs at least 130 frost-free days and between 30-60 inches of annual precipitation.
Limited Garden Value
While white mulberry produces abundant fruit that ripens from spring through summer, it offers minimal benefits to native wildlife and pollinators. The small, green flowers bloom in early spring but aren’t particularly showy or beneficial to bees and butterflies. The tree is wind-pollinated rather than insect-pollinated, so it doesn’t support our struggling pollinator populations.
Why You Shouldn’t Plant It
Beyond its invasive status in some regions, white mulberry simply doesn’t earn its place in a thoughtfully designed native garden. It:
- Competes with native species for resources
- Provides minimal ecological benefits
- Can escape cultivation and establish in natural areas
- Takes up space that could be used for beneficial native alternatives
Better Native Alternatives
Instead of white mulberry, consider these fantastic native options that provide similar benefits without the ecological risks:
- Red mulberry (Morus rubra) – The native North American mulberry with similar fruit and better wildlife value
- American elderberry (Sambucus canadensis) – Produces edible berries and supports numerous wildlife species
- Serviceberry (Amelanchier species) – Beautiful spring flowers, tasty berries, and excellent wildlife food
- Wild plum (Prunus americana) – Gorgeous spring blooms and fruit for both humans and wildlife
The Bottom Line
While white mulberry might seem like an easy-to-grow option, responsible gardeners should skip this non-native species in favor of native alternatives that support local ecosystems. Our gardens can be powerful tools for conservation, but only if we choose plants that belong in our landscapes naturally.
Remember: every plant we choose is a vote for the kind of world we want to create. Let’s make those votes count for native species that support the wildlife and ecosystems that call our regions home.
