Project Overview
RED MULBERRY
The introduction of the foreign White Mulberry to North America was disastrous for our native Red Mulberry. It hybridizes readily with Red Mulberry, polluting the native population such that finding a pure Red Mulberry in our area is nearly impossible.
White Mulberry (Morus alba) was introduced in the 1600s by colonists in a effort to start a Silk industry in North America. This means that the White Mulberry has had 4 centuries to establish, proliferate, outcompete, and hybridize with our native Red Mulberry (Morus rubra).
During that time, it was actually LAW that citizens had to plant White Mulberries. For example, in 1624, the legislature of Virginia required that every male resident had to plant at least 4 white mulberry trees on their own lands to promote the budding silk industry.
For this reason, pure Red Mulberry is now extremely rare to non-existent in our area.
PROJECT DETAILS
Our project has 3 main goals:
Create a morphological assessment key/protocol to confidently identify pure Red Mulberry from hybrids with White Mulberry.
Find regionally close wild Red Mulberries to plant out into germplasm conservation orchards that will be maintained by partner sites on protected lands in Delaware.
Propagate pure local Red Mulberries to distribute and raise awareness of the problem with hybridization, as well as get more people to taste and grow this delicious native berry as a garden tree and perhaps even a crop.
UPDATES-
April 2025 -
A robust morphological assessment key has been compiled and is currently undergoing validation by examining over 90 Morus rubra samples using microscopic morphological traits (such as trichome density and petiole groove/vascular bundle orientation) to compare against whole genome testing.
We continue to try to source pure Morus rubra outside the historical areas where White Mulberries were introduced. Many seed and seedling vendors continue to inadvertently sell hybrid Red Mulberries as pure. Some morphologically pure seedlings are in the greenhouse to prepare for the start of plating onto partner sites next year.