3-lobed Black-eyed Susan
Rudbeckia triloba
Flower colour
Numerous small, golden-yellow flowers (about 1–2 inches wide) with dark, chocolate-brown central disks.
Bloom time
Mid summer through fall
Height
24-60"
Light
Prefers full sun to partial shade. It is more shade-tolerant than the common Black-eyed Susan (R. hirta).
Moisture
Average though it is quite adaptable. It can handle clay, loamy, or slightly rocky soils and has moderate drought tolerance once established.
Native to Ontario
Non-native
Ecological benefit
Because it blooms so late and so profusely, it is a vital nectar source for bees, wasps, and butterflies preparing for winter or migration. It supports several species of Andrena bees (mining bees) that specialize in the Asteraceae family. Like its relatives, it serves as a larval host for the Silvery Checkerspot butterfly.
Notes
The abundance of small seeds makes it a high-value winter food source for songbirds, including chickadees and finches.