Soil: Sand to clay
Light: Full sun to part sun
Bloom colour: Yellow and orange
Bloom period: Mid-summer to frost
Height: Up to 7 feet (see species notes)
Moisture: Dry to medium
Attracts: Mostly attracts bees and syrphid flies, but butterflies may stop as well.
Notes: For attracting bees, typical coneflowers are a bit overrated. They do
attract good numbers of syrphid flies and sweat bees.
The most common garden variety seems to be Rudbeckia fulgida, which is often grown en masse or with purple coneflower. This particular species can be grown in zones 3 to 9 and tolerates a range of moisture conditions. It is usually 2 to 3 feet in height.It is an introduced species in Ontario so you are not likely to find this species in a native plant nursery. This species is perennial and can spread by rhizomes. This makes it suitable for growing large patches but it may require some cutting back when grown around other plants. It has a somewhat similar appearance to shorter-lived Rudbeckia hirta.
Rudbeckia hirta is useful for slope stabilisation and growing in drier soils. Being an annual or biennial, it spreads by reseeding prolifically. Each year these seedlings can be collected in spring and replanted en masse with amazing effect. The fertile disc flowers last only a few weeks and this is the time when many pollinators will visit the plant.You can observe bees working their way around the disc to obtain nectar and pollen. The infertile yellow ray flowers remain in bloom for much longer than the disc flowers and allowing us to enjoy these plants for a large part of the summer. In sandy soil, this plant is definitely biennial and will flower more profusely in its second year of growth. Wait until late spring to see if there is any growth from each plant before you pull them out.
Rudbeckia triloba is an exotic of Ontario, but native to the USA; however, it has become naturalised in the province. It has smaller and more numerous flowers. It is short-lived but reseeds easily. You may see it sometimes growing in the wild as it has escaped cultivation, but you are more likely to find it in gardens.
The taller coneflowers (see below), which grow 6 feet (2 m) high, are excellent bee attractors.My favourite is actually the hybrid Rudbeckia 'Herbstonne', a cross between Rudbeckia nitida and Rudbeckia laciniata. Although it does not produce seeds for birds, its large flowerheads are attractive to bumblebees and butterflies.Like all other tall plants, it should be planted at the back of a mixed border. It can handle part-sun and grows quickly in clay soil. It may completely flop during large storms so provide it with a couple of layers of support as it grows. While native plants are the preferred choice in a wildlife garden, you may find this hybrid easier to manage than the native Rudbeckia laciniata, which can spread too easily by underground rhizomes.
Rudbeckia laciniata, cutleaf coneflower, is great as a specimen plant occupying a larger space or as a background plant. It needs more moisture than the hybrid and if you can give it the right conditions, it will provide at stunning backdrop at the height of blooming. I would highlight Rudbeckia laciniata as an excellent plant to attract beneficial wasps. It flowers in the latter half of summer when there are many bumblebees and wasps around to pollinate the plants.
Grey-headed coneflower is taller than Rudbeckia fulgida or Rudbeckia hirta, but you may want to consider it as an alternative pollinator plant.