When the snow begins to fall, it brings a change in work for the Arboretum land care crew. Chainsaws and forestry mowers rumble to life and critical steps toward prairie and oak savanna restoration begin. This time of year is also when the land care crew creates seed mixes to sow seed and overseed in restoration areas. In 2022, we collected a record total of 377 pounds of seed from 163 species. This amount was then nearly doubled by two donations. One $15,000 gift from a generous donor allowed us to buy 240 pounds of seed. In addition, Ron Endres collected and donated 124 pounds of seed. This year has proved to be a record-breaking year in terms of seed weight and number of species obtained.
Seed collection commences in late spring when ephemerals produce fruit. Numerous species then set seed between July and late November. The land care crew diligently monitors the prairies and woodlands to collect seed from species as they are ready. Once collected, the seeds are laid out to dry. Then the crew puts the seed through a hammer mill to loosen the seed and scarify (open) the seed coats. Scarification is an important step for germination of many prairie species. The crew then divides the seed and mixes it with wood shavings to make it easier to plant. The timing of sowing is another important consideration, as many prairie species need two to three months of below-freezing temperatures to successfully germinate in the spring.
We begin to create seed mixes for specific units of the Arboretum by looking at the habitat type where particular plants will grow. Some plants prefer it wet, and others very dry. We also consider the plants’ sunlight needs – some need full sunlight while others prefer nearly complete shade. We have many wetlands with a high density of cattails, so finding native species that can establish well in those areas is important. In recently forestry-mowed areas, such as Lost City Forest or the Southwest Grady Savanna, it is critical to include pioneer species that establish well in disturbed conditions.
Thanks to generous donations and the successful efforts of our land care team, we will be able to sow the largest and most diverse seed mix ever in our new restoration areas. Plant diversity is beneficial for several reasons. Different species will bloom and produce fruit at different times of the year, providing pollinators and animals with food sources as the seasons change. Diverse plantings also support different habitats for mammals and insects that need specific host plants.
In 2022, the crew forestry-mowed a total of twenty acres – nine at Lost City Forest and 11 at Southwest Grady Savanna. Both sites were choked with invasive species such as bittersweet, buckthorn, and honeysuckle. Most of this year’s seed will go to these two places, and the new growth will hopefully provide some competition for the invasive woody species. We use repeated management practices such as prescribed fire, selective herbicide treatment, and re-seeding to help the native vegetation establish.
Any remaining seed will be put down in areas that need overseeding – the process of putting down seed in areas where beneficial plants have established but we would like more plant diversity. Restoration has many steps and seed collection and sowing are key to success. We are proud of our accomplishments this year and thankful for our donors who helped make this a record seed year.
—Land care staff, Chelsea Camp, Chris Kregel, Balin Magee, Lance Rudy, and Michael Hansen