I love adding drama to a garden, especially choosing a plant that will stop you in your tracks with your mouth gaping open! One such plant is the giant coneflower (Rudbeckia maxima). It’s a coneflower on steroids that is native to the Central and Southern United States. The genus name is in homage to Olof Rudbeck (1630-1702), a Swedish botanist who developed the first botanical garden in Sweden.
This beautiful perennial is hardy in USDA planting zones 4 to 9. Plant it in moist, well-drained, organically rich soil. It is best planted in full sun but will tolerate light shade. It can be grown from seed, but if you’re impatient, check your local nursery for plants. If your giant coneflowers are planted in the right place, they will self-sow or spread by rhizomes to form a large mass.
Blooming in June and July, the long-lasting yellow 3-inch flowers have a 2- to 6-inch brown cone. The bloom stalks can reach a height of 6 to 8 feet. The 2-foot-long basal leaves are a striking bluish-green, sometimes giving the common name cabbage coneflower. It is essentially a trouble-free perennial, but slugs and snails might feed on young plants. Be sure to plant with good air circulation to prevent powdery mildew. Plants in good health usually recover from mildew, so fungicide applications are usually unnecessary.
Giant coneflower is an excellent addition to a pollinator garden, wildflower meadow, or borders. It’s deer, rabbit, and vole resistant. I always leave the flower stalks as goldfinches and other small songbirds love to feed on the seed in the winter months.
If you want a real conversation piece, then giant coneflower is just the ticket to add to your perennial collection. For more information on pollinator gardens, see HGIC 1727, Pollinator Gardening.