By Mary Leigh
[from summer 2026 newsletter]

Dubuque Audubon purchased four 3-4′ eastern white pine and two 2-3′ white spruce for approved planting at Mines of Spain SRA. Three volunteers planted, caged, and watered the six trees on May 1st. 

The trees were divided between the Mines of Spain south entrance and Riprow Valley (two pines and one spruce at each location). We hope these new trees will prove to be a good initial size, growing faster than bare root seedlings, while avoiding the adjustment delay often seen with larger trees.

The cages are to protect these small trees from bucks, who like to rub their antlers on young, pliable trees, removing bark and potentially killing the trees. Once these trees are older, their trunks are no longer so appealing for antler rubbing, and the cages are no longer needed for that purpose. 

As a separate issue, deer find eastern white pines to be very tasty, so they’ll eat whatever branches they can reach. The cages are also an attempt to protect some parts of the pines from being eaten, to allow them to eventually get tall enough to have branches that are out of reach for deer browsing. White pines are native and fast-growing (2-3 ft per year or more) and will grow up to 80+ ft tall and 25 ft or more wide. They can live over 100 years in windbreaks but usually have a shorter lifespan due to breaking in wind and ice storms.

Deer are far less interested in browsing on white spruce, so hopefully these trees will retain their lower branches, but the cages are still needed initially as protection from antler rubbing. Deer do not normally eat white spruce unless they can’t find other options, such as during a particularly harsh winter with lots of snow. White spruce are medium to fast-growing (2+ ft per year) and will grow up to 60+ ft tall and 20+ ft wide. They can live 80+ years in windbreaks, and heavy snow and ice storms cause little damage.

Below are photos of mature trees for both species, where the cages were removed many years ago, to clearly show the deer browsing preference!

2024 Tree Planting Follow-up

Some may recall that Dubuque Audubon planted 16 eastern white pine bare root seedlings at Mines of Spain in May 2024. One of the survivors can be found at the south entrance (see photo) near the two larger pines we just added. It may continue to struggle in shady conditions, but we hope that removing competing grass around it this year will help.