Garden Wednesdays, Tall Thistle, + Kidical Mass

Thank you to all who joined last Saturday’s Open House. It was wonderful to see everyone, and we got so much done—repaired fences, transplanted raspberries, continued to gather important native seeds, planted community cold frames, and more!

Join us on Wednesday, 5:00pm until dusk, to keep the good work going!

Read to the end to check out some other magnificent gardening events happening in Chicago this month and next. And save the date for Kidical Mass on Sunday, Oct. 22, which will start at Waters School and end with a celebration in the garden! More info on that below.

Focus on… Tall Thistle

Thistles tend to have a bad reputation as garden weeds. Certainly the non-native Canada thistle (which has nothing to do with Canada) is one of the worst invasive species in Waters Garden, but even so, its flowers are actually quite pretty. The native tall thistle (Cirsium altissimum) is definitely a pretty plant. Like the sunflowers discussed previously, thistles are members of the Asteraceae family, meaning that their blooms are actually composites of many tiny flowers. However, thistles lack ray florets and only have disc florets, which are usually purple colored. Last time, I mentioned the involucre on the rear of the sunflowers; the involucre is a whorl of leafy bracts on the rear of composite flowers, and with thistles, it is what gives the flowers their distinctive shape. The involucre of the tall thistle is somewhat bell-shaped and is covered in tiny spikes.

One way to tell tall thistle from other native thistles—especially the similar-looking pasture thistle—is the shape of the leaves. The leaves of tall thistle are either not lobed at all or are only shallowly lobed, whereas most of the other native thistles have deeply lobed leaves. Note though that there is quite a lot of variation, and the tall thistle plants currently growing in Waters Garden actually have quite prominently lobed leaves. In addition, the leaf undersides (known as the abaxial surface), but not the upper sides (known as the adaxial surface), are whitened by a dense mat of hairs. Botanists use the term tomentose to describe hairs this dense and matted; there are over 30 terms for the varying levels of hairiness of plants in the glossary that I have, which may seem excessive but it allows for precise descriptions of plants.

Tall thistle is largely biennial (living for only two years), though it can survive a few years longer than two. A variety of bees, butterflies, and moths visit tall thistle flowers for nectar. Then, when it goes to seed, it provides food for goldfinch, sparrow, siskin, and junco. So while short-lived, this under-appreciated plant is definitely a strong contributor to the garden ecosystem. Tall thistle grows under the southeast bur oak in Waters Garden; check them out while they are still in bloom.

The “Focus On” series is written by Jeremy Atherton, the parent of a Waters 5th grader. He is a research scientist at Northwestern University Medical School. In addition to volunteering at Waters Garden, he is a steward at Riverbank Neighbors and a member of the 47th Ward Green Council.

Save the Date for Kidical Mass—October 22, 2023!

Join Kidical Mass for a slow, easy-going, and fun group ride focused on kids of all ages and families that will tour the Lincoln Square neighborhood!

Gather @ Waters Elementary 10:00am; depart @ 10:30am. Return to Waters @ 11:00ish for a Garden Celebration, including stories, hot cider, and more fun activities.

Festive dress and decorations encouraged. All kids must bring a parent/guardian with a bike.

More Garden Events Around Town

Check out upcoming gatherings in the Chicago Community Gardeners Association free fall event series!

Garfield Park Community Gardens Tour
Saturday, September 23 • 9:30am–2:00pm
More info and register here.

Oriole Park Teaching Garden Is Turning 10!
Saturday, September 30 • 1:00–3:00pm
More info and register here.