As you drive through Iowa, there are some plants that always seem to catch your eye - even at 55 MPH!
The species of plants that grow along roadsides are often tough and prolific plants. Some are natives taking advantage of the unmown roadside or ditch. Others are not native and grow well in the challenging conditions found along the road. Some of these plants (especially the non-natives) are considered weeds and some can be quite problematic in certain settings. However, along the road these plants - native or not - provide blooms, erosion control, and beauty, among other things.
Below are a few common blooming roadside plants you may see on your next road trip. They are organized roughly by bloom time.
These are just a few - many more beautiful flowers can be seen while traversing the highways. Learn more from the Iowa Living Roadway Trust Fund.
Dame's Rocket
Hesperis matronalis
Bloom-Time: May to June (July)
Native Range: Europe
Pink to white clusters of flowers appear atop 2 to 4 foot stems. Plants set enormous amounts of seed that grow easily in disturbed sites like roadsids. This biennial plant is often confused with the native phlox. Phlox flowers have five petals where Dame's rocket has 4 petals.
Foxglove Beardtongue
Penstemon digitalis
Bloom-Time: May to June
Native Range: eastern and central North America
Pale pink tubular flowers bloom along short talks, rising 2 to 3 feet tall. This native perennial grows in a wide variety of conditions, from full to part sun and average to moist soils. Plants are attractive to hummingbirds, butterflies, and other pollinators.
Crown Vetch
Securigera varia
Bloom-Time: May to September
Native Range: Europe, Asia, and northern Africa
Plants are often covered in pink, pea-like blooms. This spreading plant is frequently spotted while traveling as it was intentionally planted along the roadside as it establishes quickly from seed, reducing erosion. It can be an aggressive spreader and is difficult to eradicate once established.
Yellow Goat's Beard
Tragopogon dubius
Bloom-Time: May to September
Native Range: Europe
Yellow daisy-like flowers appear on tall stems and are surrounded by green bracts much longer than the petals. Blooms open in the morning and close by mid-day, so sometimes you only see the elongated pod-like flower bud. Seed heads are similar to dandelion.
Pale Purple Coneflower
Echinacea pallida
Bloom-Time: June and July (sporadic until frost)
Native Range: eastern and central North America
Flowers have pale purple petals that droop downward from a large coppery-orange cone-shaped center. Plants grow 2 to 3+ feet tall. They prolifically set seed and tolerate poor soils and part-shade, making them common along roadsides.
Birds-foot Trefoil
Lotus corniculatus
Bloom-Time: June to August
Native Range: Europe
This low-growing plant's bright yellow pea-like flowers grow well in disturbed sites and are frequently found blooming along road edges. It is occasionally a lawn weed and is sometimes found in forage seed mixes furthering its spread.
Ditch Daylily
Hemerocallis fulva
Bloom-Time: June to August
Native Range: Asia
Orange flowers (that last only a day) arise above grass-like foliage. Unlike many clump-forming cultivars found in garden centers, this daylily spreads aggressively, especially in wet roadside ditches.
Ohio Spiderwort
Tradescantia ohiensis
Bloom-Time: June to August
Native Range: central North America
Bluish (sometimes pink or white) flowers have three broad petals and arise from grass-like leaves. These perennials do well in a wide range of soil conditions but prefer slightly wetter locations.
Milkweed
Asclepias syriaca
Bloom-Time: June to August
Native Range: eastern and central North America
Clusters of small pale to dark pink flowers form on 2 to 5 foot tall stems lined with large oval to oblong leaves. Plants grow well in disturbed sites, including roadsides, and can become weedy in certain situations (crop fields). They are well-known to be one of the host plants for monarch butterflies.
Mullein
Verbascum thapsus
Bloom-Time: June to August (September)
Native Range: Europe, northern Africa, and Asia
Distinctive spikes of yellow flowers are arranged along a thick bluish, gray-green stem that rises above a rosette of hairy leaves. This biennial plant produces stalks that are 5 to 10 feet tall.
Grey-Headed Coneflower
Ratibida pinnata
Bloom-Time: June to August (September)
Native Range: central North America
Daisy-like flowers have a raised, cylindrical grey central cone surrounded by bright yellow petals that hang downward Blooms form on tall 3-5 foot stems. Plants tolerate drought and poor soils well.
Daisy Fleabane
Erigeron strigosus
Bloom-Time: June to September
Native Range: eastern and central North America
Chances are, if you see small (less than 3/4 inch) white, daisy-like flowers blooming along the road, it is some type of fleabane! This common native spreads easily and is typically a short-lived perennial. Other species are annual, and many are considered weeds in some garden settings.
Queen Anne's Lace
Daucus carota
Bloom-Time: June to September
Native Range: Europe
It's so common that you almost think it could be native. White flat top clusters of flowers rise above ferny foliage. These biennial plants spread primarily by seed and do well in a wide range of conditions. Problematic cousins to Queen Anne's Lace are also commonly found near roadsides. Poison hemlock is distinguished by its purple spotted stem, and wild parsnip has yellow flowers and coarser foliage.
Hoary Vervain
Verbena stricta
Bloom-Time: June to September
Native Range: central North America
Blue-purple (sometimes pink-purple) flowers bloom from the bottom up along densely packed spikes that elongate as they bloom. Plants do well in dry fields, prairies, and roadsides.
Chicory
Cichorium intybus
Bloom-Time: June to October
Native Range: Europe, central Russia, and western Asia
Sky blue flowers form on tall stems. The basal foliage looks similar to dandelion foliage. This perennial plant has a thick taproot and thrives in disturbed sites like roadsides.
Ironweed
Vernonia fasciculata
Bloom-Time: July to September
Native Range: eastern North America
Flat to dome-shaped clusters of purple flowers appear on top of 3 to 6-foot stems. This perennial prairie native does well in low areas, ditches, marshes, and consistently moist soils.
Compass Plant
Silphium laciniatum
Bloom-Time: July to September
Native Range: eastern and central North America
Yellow, 2-4 inch, sunflower-like flowers are borne on stalks that rise high above the surrounding grasses (8-10 feet tall). The deeply lobed leaves tend to orient themselves north to south (hence the common name)
Goldenrod
Solidago
Bloom-Time: July to October
Native Range: many species native to eastern and central North America
Dozens of different species bloom along Iowa's roadsides. Hundreds of small yellow flowers cover branched flower clusters late in the growing season. Heights depend on species and ranges from a few feet to 7+ feet.
New England Aster
Symphyotrichum novae-angliae
Bloom-Time: August to October (November)
Native Range: eastern and central North America
Tall plants are covered in pinkish-purple daisy-like flowers late in the growing season. As one of the latest common roadside plants to bloom, it is often seen covered in pollinators like butterflies and bees.
More Information
- Native Perennials for Moist to Wet Soils
- Native Woodland Wildflowers for the Home Garden
- Landscape Plants for Difficult Sites
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