August 2025 Newsletter

The summer is winding down, but that doesn’t mean the fun is over!

Wild Senna at the HQRA

To start, we want to introduce you to a special member of the legume family - wild senna (aka, American senna, Senna hebecarpa). These unique wildflowers are large, long-lived perennial species with showy yellow flowers and fern-like compound leaflets. Mature plants can reach up to 6 feet tall! The species is considered endangered or threatened in some Northeastern states, like Massachusetts, and is regarded as a “Watch List” species in Illinois. Habitat loss is the prime contributor to the species' decline. It is native to Illinois and can be found statewide. Aside from wildlife benefits, wild senna is an excellent plant for soil stabilization thanks to its deep root system. We planted wild senna at the Heritage Quarries this winter as part of our restoration efforts, and as you can see in these photos, it is already beginning to thrive.

Wild senna is an important species that supports a variety of pollinators and other insects. Club-shaped glands at the base of the leaves secrete nectar that is consumed by ants, ladybird beetles, and flies (source). Bees seek out the flowers; various butterfly and moth larvae eat the foliage. Sulphur butterflies are particularly dependent on wild senna. As caterpillars feed on wild senna, they release chemicals called caramones that deter predators and attract pollinators like bees.

Restoration Update

While summer isn’t quite over, it is time to start thinking about the end of the year. For us, it is going to involve a lot of maintenance work! Last fall and winter, we cleared a large amount of invasive overgrowth for the prairie and shoreline restoration projects and began native seeding. Native prairie grasses typically take 3 years before they gain substantial height and start dropping seed. Some wildflowers can take 5 years or longer to reach maturity! To support their growth, we’ll continue selectively clearing, weeding, and seeding the prairies and shorelines during the winter months. This activity allows sunlight to reach desirable plants while preventing seed development and the spread of weedy species. 

Overall, the areas we cleared over the last several seasons are responding very well. The oldest section of the prairie is coming in strong, with native species like hairy beardstongue, daisy fleabane, wild senna, wild bergamot, coneflowers, Ohio spiderwort, Illinois bundleflower, boneset, rattlesnake master, wild white indigo, field goldenrod, big bluestem, little bluestem, switch grass, and broom oval sedge being sighted over the summer. There is still much work to be done, but the success of these species is a great sign for the future. TWWT will continue to broadcast native seed mixes developed with our restoration partner, Stantec; planting will occur in the fall and spring. 

The newly cleared section will continue to develop for the next two to three years until the native forbs are completely established and achieve their full height. Many native prairie grasses and forbs spend their first few years developing their root systems and do not gain much height or flower during this time. Once established, these species are long-lived, providing soil stabilization and valuable food and habitat for a wide variety of wildlife.

Join Us for Quarry Care

Quarry Care will be back this October! Register today to join us in the restoration of the Heritage Quarries Recreation Area. This October, we will be conducting brush pile burns to clear previously cut woody invasives (mainly buckthorns, bush honeysuckles, and tree-of-heaven). Brush pile burns are an effective and controlled method for clearing removed woody material. Burning woody material can release minerals and nutrients into the soil, enabling expedited nutrient delivery. It also reduces the volume of the wood by a significant amount, opening up space for new plants to grow. 

Speaking of new plants, consider registering for our November Quarry Care date! We will be hand broadcasting native prairie, pollinator, and shoreline seed mixes that we developed with Stantec. The mixes contain a variety of native grasses, sedges, and forbs. If the Quarry Care dates don’t work, but you still want to volunteer, also consider our adopt-a-trail program or reach out to organize your very own volunteer day!