Fall Flowers Add Color to the Garden
"Native wildflowers and their cultivars - yellow goldenrod, purple asters, golden sunflowers, and dusty rose Joe Pye create a lot of interest not only because of the attractive flowers, but also, the amazing variety of native butterflies, moths and other insects that feed on them," said Nancy Pollard U of I horticulturist.
"Fall wildflowers are particularly outstanding at attracting adult moths and butterflies, which lay eggs that hatch into larva (caterpillars). The larvae provide a high protein source of food for many birds, particularly warblers and neo-tropical migrant birds of conservation concern. Birds are very good at keeping populations of these insects in check, so it is a very good situation for all."
Flowers that bloom in the fall can to be tall - two feet to six feet or more depending on the species and cultivar. They often work best at the back of the flower border. Some varieties have been selected and given cultivar names because they are shorter, more compact or more disease resistant than the average species plant. Cultivars are usually propagated by cuttings. Cultivars do not always come true from seed, so you may want to cut back stems after flowering to prevent selfseeding of cultivars.
While there are some perennial sunflowers (Helianthus sp.) available commercially, Helianthus annuus, the native annual is so beloved, it is a garden staple. There is a sunflower for every garden situation ranging from the 16 inch 'Elf' to the three-foot 'Solar Flash', to the 12- foot Mammoth. The color palette has expanded from yellow with a brown center, to whites, burgundies, rose pink, with many tints and shades of colors in between. "While easy to grow from seed, sunflowers prefer sun," Pollard noted.
Joe Pye (Eutrochium, formerly Eupatorium) is a great plant not favored by deer. The showy 'Gateway,' has burgundy stems four to six feet tall, topped by dusky rose nosegays a foot across. Cut back the tips in June to create a bushier plant. It is a magnet for butterflies and birds in the fall. Joe Pye prefers full sun, and likes average to abundant water.
Goldenrod (Solidago sp.) thrives in sun to part sun and are deer resistant perennials. They are stunning paired with blue and purple New England asters. Many species are available. Great performers include:
- Solidago flexicaulis 'Variegata' with variegated foliage it brightens semi shaded wooded areas. This goldenrod is over four feet tall and has a spreading nature. It blooms from early September to mid-October.
- Solidago sphacelata 'Golden Fleece' which has pyramidal densely flowering stems that form a compact groundcover, 18 to 36 inches depending on site conditions. It is drought-tolerant and is also good for fall container gardens. September flowers attract hummingbirds, bees, and butterflies.
- Solidago rugosa 'Fireworks' has graceful fine textured foliage with arching branches. The stems of the golden blooms arch in multi directions like fireworks. It grows three to four feet tall. It tolerates wet soil, and grows slowly by underground rhizomes, but generally doesn't get out of hand. It blooms mid-September to late October.
Asters (Symphyotrichum but widely sold as aster) do well in sunny sites with good air circulation, or their foliage might suffer from mildew. Pinch back the taller varieties until June as you would chrysanthemums. Most will tolerate sandy, clay, poor soils and some drought. There are mixed reviews whether these are deer resistant or not, leaning towards not. It depends on many factors.
Two favorite asters trialed at the Chicago Botanic Gardens are New England aster, A. novae-angliae 'Alma Potschke', a three-foot, showy reddish pink and 'Purple Dome' a dwarf (18 inches) purple.
- Aromatic aster (Symphyotrichum oblongifolium, formerly Aster oblongifolius) was also a Chicago Botanic Garden favorite. Abundant sky-blue flowers are borne on stiff, one to three foot stems into October or later before frost. The cultivar 'October Skies' is a winner at just 18 inches high.
- Aromatic Aster 'Fannys' is a good cultivar with abundant 1.5 inches, dark purple and yellow flowers. Blooms late in October or even November. The gray-green, rust resistant fragrant leaves spread to form large clumps three to four feet tall. It grows easily and quickly in dry to average conditions and tolerates clay or sandy soil.