Trader Mulberry

We’ve combed through a fair bit of info on Trader Mulberry by Dr. Jim Walla, who released this variety in 2015. Trader is perhaps the most cold-hardy named variety (some debate with Northrop), as the original tree survived -44°F near Oriska, North Dakota.

A Hardy History

The history of Trader is quite fascinating. It was brought over from Germany by the Trader family when they immigrated to the U.S. in 1882. The original tree is still in North Dakota, having borne fruit for over 140 years. According to Walla, he believes this to be either pure Morus alba, or largely alba with a small amount of M. rubra, as its cold hardiness supports this—considering rubra is much less cold-hardy.

Fruit Production & Flavor

It will produce an abundance of large, sweet, glossy black fruits throughout the entire summer. The berries are very small the first year and don’t set very heavy fruit in the first few years. The fruit size should increase every year after it first bears, going from 1/2” to 1 1/2” several years later. The fruit is excellent for fresh eating, preserves, and juice/wine. Poultry and livestock love both the fruit and the leaves.

Growth Habit & Hardiness

Can be grown as a multi-stemmed shrub, as a single-trunk 35' tall tree, or much shorter if summer pruned. Will begin fruiting at only 3 years, and will produce for a century or more! Walla observes that this tree could potentially be grown in zone 3a, but he does not know of any currently growing that cold. Safe to say this is hardy to Zone 3b, or -35°F.

Spring 2025 Stock Details

These trees come in a couple different sizes, and in order to maintain the exceptional hardiness of these mulberries, they’re rooted out on their own roots—no rootstock or graft.

These trees are 1–2.5 ft tall.

Photo Credit: Jim Walla