What Are Those White Bags All Over Campus?
If you’ve spent time at Reflection Riding lately, you might have noticed white mesh bags placed over the seed heads of various flowering plants across our campus and wondered what they’re doing there…
Some people might mistake the bags for litter and pull them off of plants, but we promise they are intentional! We wanted to explain what these bags are for and why they are beneficial!
Seed bags provide an easy and effective way to collect seeds from plants throughout the growing season. Native plant material is the basic building block of any healthy ecosystem, so being able to collect native seeds hyper-locally is essential to much of the conservation and restoration work that we do here at Reflection Riding and across Chattanooga.
While our team frequently collects seeds by hand without using seed bags, there are several reasons why the bags make it easier. For one, the time that seeds are ready to drop from plants can be highly variable. Especially given increasingly unpredictable climate fluctuations, seeds may drop earlier or later than historical data suggests. Also, some plants can bloom at different times depending on the environment they are grown in—a flower growing at the edge of a pond might drop its seeds before a flower of the same species growing in a meadow. Rather than trying to predict the biological clock of each plant, seed bags can catch seeds whenever they ripen and drop.
Another reason why seed bags make collection easier is that different plants have different dispersal methods to transport their seeds far away. Some are adapted to catch the wind, some get eaten by wildlife, some attach themselves to insects or animal fur, and some even explode or eject their seeds. For any of these dispersal types, a seed bag can effectively catch the seeds. At the same time, a bag can act as a physical barrier to protect the seeds of rare or endangered species from being eaten by birds, insects, deer, or other wildlife.
Photo Credit: Grant Dotson
The bags don’t interfere with the pollination process because they are put onto the flowers after they bloom and are effectively pollinated. We also refer to the guidelines of Seeds of Success—a national native seed collection program led by the Bureau of Land Management—in deciding which populations to collect seeds from. Then, our Native Plant Nursery staff checks the bags regularly to see if the seeds have dropped. Some seeds might need to be planted right away, but others we will store to be planted at a later date. Whenever they are ready to plant, we can mimic the natural processes that break the dormancy of seeds in several ways using various stratification and scarification methods. Our nursery team is excited to have recently received a grant for a new fridge—this means we have more storage space for collected seeds and are better equipped to safeguard vulnerable species!
Building up a bank of native seeds is vital to restoring damaged ecosystems, creating resilient native habitats, and supporting the overall biodiversity of our area. Collecting seeds on our own property is beneficial because it enables us to cultivate a healthy localized ecology. But we also collect seeds from other areas around Chattanooga through a partnership with Tennessee River Gorge Trust and Southeastern Grassland Institute. Working with these organizations means that we can gather seeds from diverse ecosystems—from the valleys to plateaus—where plants have developed resistance to different environmental conditions. In doing so, we are taking an important step toward safeguarding the genetic diversity of native species, making them more resilient in the face of unpredictable weather patterns and habitat degradation.
Next time you are walking on our campus, keep an eye out for seed bags—but please don’t disturb them!
Photo Credit: Grant Dotson