Delaware Butternut Search and Rescue (2023-2026)

Also known as White Walnut, the Butternut tree is often seen growing alongside Black Walnut, but is found mostly in the more rocky Piedmont region of the Delaware Valley Region in very close proximity to creeks and streams.

It is native throughout most of Pennsylvania and the northern portion of Delaware’s New Castle County above the “fall line” that separates the rocky Piedmont from the flat and silty/sandy Atlantic Coastal Plain to the south.

Our goal for Butternut Conservation Project has 2 main goals:

• Phase 1 - Find and document any remaining native wild PURE Butternut Tree’s in Delaware.

  • In order to preserve these genetics, we want to propagate these wild trees. Grafting would be best to ensure purity, but seedlings are best for genetic diversity. In either case, DNA testing will be required before these seedlings are incorporated into a conservation plot.

  • STATUS -

    • May 2024. Several potential trees found, DNA sample collection in progress.

    • Sept 2024. Phase 1 completed with over 80% of accessible trees surveyed for visual assessment. Surviving trees have been submitted for DNA testing.

• Setup 2 - Setup pure conservation plots within the Delaware Valley Region containing several pure Butternut trees (at least ). The goal here is both local genetic conservation of individual trees, but genetic diversity for the entire plot. This will include PURE Butternut trees from

  • Northern Delaware and Southeastern Pennsylvania

  • From the Piedmont 8.1.3 Ecoregion south to Virginia for climate adaptation

  • From the Midwest for increased genetic variation in hopes of finding canker resistance

  • STATUS -

    • May 2024. Plantings in place with 3 partner sites on protected lands using pure USDA trees.

    • Sept 2024. Research continues on tissue culture, pollen collection and storage, and seed propagation of local native pure trees.

Restoration

When the project is completed, we use the seedlings from the above Conservation plots to screen for natural resistance to the canker. Promising seedlings will continue to be planted on protected lands.

A note on hybrids

Due to the presence of foreign Japanese Walnut throughout the east coast, naturally occurring hybrids are now common. There are reasonable arguments both for and against the use of hybrids in the search for canker resistance, however, that is not part of this project. We leave those efforts to others who are more passionate and knowledgeable about the use of foreign genetics as part of the solution. Instead the focus of this project is only on finding, preserving, and blending local germplasm with pure genetics from across the Butternut’s native range to give them the best chance of naturally adapting to the Canker on their own.