The Problem with Redbuds

Eastern redbud is a common native understory tree and a popular choice for both residential landscapes and street trees. One of the harbingers of spring in Missouri, the clusters of small rose-purple flowers make a gorgeous display even before the heart-shaped leaves appear themselves.

The blooms of late March to early May are a nectar source for bees. Humans can enjoy the blooms themselves in a variety of ways. Fresh blooms can be enjoyed in salad, incorporated into baked goods, fried and sautéed dishes, or even nibbled right off the branch if you feel daring. For a taste of spring year round, you can even pickle and jelly the blooms. Seed pods form as early as September, and are enjoyed by several species of birds. The tree’s leaves turn yellow in fall, and the seed pods hang onto the bare, graceful branches through winter and even into spring.

Eastern redbuds are found statewide as they are able to grow in a wide range of soil conditions. They tolerate both full sun and partial shade; more blooms will form in full sun. They tend to branch low to the ground and their attractive irregular branches form an attractive, arching structure. Mature trees can reach up 40’ tall and almost as wide, making them a good fit for small properties and urban streetscapes.

Eastern redbud flowers, Courtesy of MDC

Given their beauty, adaptability, and relatively small size, it is easy to see why they are a popular landscape tree and often planted in urban tree lawns. They don’t tend to cause complaints due to leaf or seed litter, and are small enough at maturity to be unlikely to buckle sidewalk or other infrastructure. When older, larger, “problem” trees are removed, and potential replacements are being considered the Eastern redbud is a very easy tree to enthusiastically welcome to your landscape. 

If there is a downside to the popularity of these beautiful, adaptable, small trees in urban spaces it is what we unwittingly forego by making that easy choice too often. Urban trees’ benefits are critical to making developed areas healthy, humane places to live, but this capacity is dependent on the species and size. For example, a large oak supports many times more native species and has a vastly superior capacity to improve air quality, reduce summer heat, and absorb stormwater. While experts like Douglas Tallamy advocate for investing in large species like oaks, what is often also left unsaid is that in many communities, we have largely lost the option to plant species like oaks on neighborhood streets. 

Young Eastern redbuds planted in a narrow tree lawn, Courtesy Erin Godwin

The mantra of “Right Tree, Right Place” reminds us to choose a species that will do well in existing planting conditions without outgrowing the available space or posing a hazard to critical infrastructure like electrical transmission lines. Unfortunately, a planting space initially large enough for an oak can be partially paved after the tree is planted. Its roots fight back against the encroaching concrete, and the unfortunate oak will become yet another large “problem tree”. With little, if any memory of what the planting space originally looked like – we neighbors will understandably blame the planters for choosing the ‘wrong’ tree. When the space is later replanted, rather than restoring the planting space and planning stewardship for the next oak, we usually learn we must plant smaller, less problematic species like the Eastern redbud in our communities. 

STL TreeLC is a new group providing residents with the training and equipment to mulch, water, clearance prune, inventory, and protect street and park trees. Ongoing volunteer urban forestry is possible with affordable and accessible technology. STL TreeLC is currently developing a web app to get new trees ‘adopted’ by volunteers to help them have long, productive lives and prevent small tree problems from growing into expensive headaches.  This increased care and attention also creates new opportunities to improve planting sites to again fit larger shade trees. With community support, STL TreeLC is hopes to support the tree canopy throughout St. Louis city and the region. 

Nice Bur oak specimen tree on University of Minnesota campus. Image Courtesy Joseph OBrien, USDA Forest Service, Bugwood.org

We must help our community really see the trees in our urban forest, so we can provide the proactive care they need and conduct the thoughtful planning and preparation needed to enable more varied species selection. We should embrace Eastern Redbuds, but we must also make space and commit to planting the larger tree species being squeezed out of our urban canopy.