Overview:
By Nichole Callicutt
Each week, Signal Akron will help you in your gardening adventures with an excerpt from "The Root of It," a monthly newsletter from the Summit County Master Gardeners, Ohio State University Extension.
The name globe thistle (Echinops ritro) may bring visions of a weedy and ornamental thug. Far from it, this thistle is a beautiful ornamental that brings an architectural element and interest to the flower bed.
The globe thistle’s genus name, Echinops, comes from the Greek words echinos (hedgehog) and ops (looks like), due to its spiky, globe-like flowers. Globe thistles are a striking addition to any garden; but more importantly, the nectar-rich flowers attract pollinators and the seeds are nutritious for wildlife.
A native of Europe, globe thistle belongs to the Asteraceae family — think sunflowers and marigolds. Like all plants in this family, the heads are a composite of numerous tiny flowers. One spherical globe contains a cluster of about 100 flower heads, each with its own set of petals, making it a standout in the garden.
This perennial is easy to grow and tolerant of summer heat without needing a lot of water. Its taproot allows it to adapt to most environments, but it likes well-drained soil. Globe thistle grows from two to four feet tall, so be mindful when placing it in your garden. Planted in May to early June, it will bloom the same year, with a bloom period from July through September, a beautiful addition to the fall floral display.
Benefits of mixing in globe thistle
Incorporating a variety of plants supports wildlife and brings biodiversity to the garden. Pollinators such as bees, butterflies and hummingbirds are highly attracted to globe thistle’s nectar, as are shield beetles, ladybugs and hoverflies. Clemson Cooperative Extension (2022) notes that hoverfly larvae can “eat over 400 aphids during its development” and that having hoverflies in your garden can reduce aphid populations in your garden by up to 70%.
Its spiny flower and spiky foliage make globe thistle rabbit resistant. Globe thistle is deer resistant and can reach a height of 4 feet, which can discourage deer from jumping over it; having it as a border plant is beneficial.
This foliage is perfect for butterfly larvae such as the thistle caterpillar, Vanessa cardui, which becomes the painted lady butterfly. And talk about birds! Globe thistle seed heads are desirable to birds such as the goldfinch. The Ohio Department of Natural Resources says, “Finches are at the top of the evolutionary line of Ohio’s birds” and are found in every Ohio habitat (ODNR, nd). Globe thistle flowers bloom into late fall, which works well for the nesting habits of goldfinches. They collect the down from mature thistles to line their nests and use the seed to nourish their young.
Globe thistles are late bloomers and last for extended periods, making them a stunning addition to the fall garden. Their ornamental silvery-blue spheres dry well, add texture to floral arrangements and make a beautiful contrasting addition to floral arrangements. They should be harvested before the pollen shows. Leave some spheres in the fall to provide a food source for late fall and winter birds. You can deadhead this perennial in the spring to prevent reseeding, but it does not need special overwintering techniques.
Although planting a thistle in your flower bed may go against your gardener instincts, give this one a try. Its beautiful flower head and foliage and the wildlife support it offers are a win-win!