Autumn Seed Collecting

As the growing season winds down, plants are producing millions of seeds.  Some of these seeds are collected every year and used in a variety of ways.

Collected seeds can be spread into areas that are not covered through natural seed dispersion.  Seeding can add diversity to a habitat to improve the quality of the area, or provide new habitat for rare and endangered plants.  Seeds add new species into disturbed ecosystems and help to establish plant diversity to overcome invasive species.  New plant species provide host food sources for insects and structure for building nests and other shelters.

The amount of seed collected depends on how much seed is available.  General guidelines are to harvest no more than half of all seed, less if the plants are only found in small populations.  To avoid adversely affecting existing habitat, seeds are collected from several locations across different days.  Seeds are usually collected in  sites that are geologically and climatologically similar or connected to the site where the seed is to be dispersed.

Seeds can be immediately sown by hand into a new or adjacent area, but many seeds are stored for later use.  Seeds are dried on racks or in paper bags to prevent mold.  If possible, the stems and leaves, known as chaff, are separated from the seeds.  Large seeds encased in hard outer shells are broken open using a hammer mill. 

Seeds in nature are exposed to many environmental conditions that play a role in determining when they will germinate.  Some seeds must be exposed to freezing, thawing, fire, moistness, or a combination of these factors in order to sprout.  Legumes require scarification, making small cuts across the skin of the seed.  Fall grasses can be stored in large quantities provided they are kept dry, whereas spring ephemerals with fleshy, moist fruits must not be allowed to dry out, and are stored in cool, moist conditions.

Seeds are often prepared in mixed batches by habitat type such as dry, wet, savanna, woodland, and wetland.  Seeds can be planted late in fall prior to the ground freezing, over winter on top of snow or frozen ground, or in spring after the first thaw.  For seeds that require freezing, plant in early winter and let nature do the work.  If a burn is likely in the area, consider dispersing the seed after the burn.

Stewards in charge of seed collecting keep extensive records of all activities.  This helps with the selection of desired seeds in the future.  Information collected may include GPS locations of seed collection sites, dates and species picked, weight of seeds after processing, and the processing methods applied to each seed species.  In addition, the species included in each seed mix and the date and location where each mix is planted can provide information for assessment in subsequent seasons.

The gallery below includes a sampling of the many seeds that are available at summer’s end including Big bluestem, Andropogon gerardii; Butterfly weed, Asclepias tuberosa; Black-eyed susan, Rudbeckia hirta; Buttonbush, Cephelanthus occidentalis; Common ironweed, Vernonia fasciculata; Common milkweed; Asclepias syriaca; Golden Alexanders, Zizia aurea; Green dragon, Arisaema dracontium; Grey headed coneflower, Ratibida pinnata; Jack-in-the-Pulpit, Arisaema triphyllum; Smooth Solomon’s seal, Polygonatum biflorum; Prairie dropseed, Sporobolus heterolepsis; Shooting star, Dodecatheon meadia; Purple coneflower, Echinacea purpurea; Wild colombine, Aquilegia canadensis.