Plant Calculator
Enter the approximate length and width of the area you will be planting and click 'Calculate' to determine how many Rudbeckia triloba you will need.
Correct and successful spacing is complex and depends on project conditions. We encourage you to call us at 877-ECO-PLUG for project specific recommendations and further assistance.
Rudbeckia triloba
three-lobed coneflower (brown-eyed Susan)
- Category: Perennial
- Hardiness Zone: 5-7
- Height: 2-3 Feet
- Spread: 12-18 Inches
- Spacing: 12 Inches
- Bloom Color: Yellow
Hundreds of small, deep gold flowers bloom July through October! A naturalizing self seeder. Biennial or short-lived perennial. Georgia Gold Medal Winner in 1997. Three-lobed coneflower is very drought, heat and pest tolerant. Prized by butterfly and hummingbird gardeners.
Green Infrastructure
| • | Meadow/Prairie |
Wetland Indicator Status
| • | Falcutative Upland (FACU) |
Plug Type
| • | Landscape Plug™ |
Propagation Type
| • | Open pollinated |
Additional Information about Rudbeckia triloba
What makes Rudbeckia triloba a solid choice for naturalizing is how it adds a soft edge to well-designed gardens with its hundreds of small, deep gold flowers blooming en masse through July through October. You should never plant just one. Three-lobed coneflower has up to 6 flowers blooming at once and each flower brings a flurry of butterfly activity. It is a naturalizing self-seeder with the tendency to be a biennial or short-lived perennial. Growing 24-36” tall and 12-18” wide, Rudbeckia triloba is a carefree plant, great for gathering in large bunches for a cut-flower display. In 1997, it was a Georgia Gold Medal Winner for its colorful display, long season of bloom, and because it is very drought, heat and pest tolerant.
Found from Vermont to Texas to Utah to Georgia, Rudbeckia triloba prefers sandy or loamy, moist soils but can tolerate periods of drought. Commonly residing in moist fields, it likes disturbed habitats such as along roadsides or rail lines. The wide variety of habitats this plant tolerates display its adaptable appeal, as long as there is full sun. In a happy location, Rudbeckia will self-sow which allows easy propagation for this short-lived plant.
Rudbeckia triloba is in full bloom after Rudbeckia ‘Goldsturm’ begins to fade but before Rudbeckia fulgida var. fulgida comes into its full glory. It has earned its place in our mid-height meadow where plants must tolerate an early summer mow and biennial burns while being less than 3’ tall to maintain sight lines. Three-lobed coneflower supports a multitude of native bees including digger bees and carpenter bees as well as the specialist pollinator, Andrena rudbeckiae. The plant is self-pollinated but that doesn’t stop the wasps, butterflies, and flies from visiting. The foliage is also fed upon by a variety of native beetles, which while it doesn’t help the lower foliage, it does help support a full range of insects for their necessary habitat.
Growing & Maintenance Tips for Rudbeckia triloba
Prefers sandy or loamy, moist soils, but is drought resistant. Spreads slowly by rhizomes. Deadhead to prolong blooming season. Propagate by seed, cuttings and division. Cut back to the ground after first frost and mulch to protect roots for the winter. Outstanding in mass plantings, as a border perennial, or in rock or low maintenance gardens.
