Plants That Are Tolerant of Road Salt

Plants near sidewalks and roads in winter are frequently subjected to the overspray of salt- and ice-melting chemicals during winter. In addition to winter chemicals, these gardening locations can lack nutrients and moisture. Not all gardening plants can tolerate these poor conditions. Gardeners must research the growing requirements of plants to determine their tolerance to road salt and other disadvantages near sidewalks, walkways or streets.

Bearded iris (Iris germanica) is a hardy perennial that is tolerant of road salt. Frequently grown as a border plant along sidewalks and roadsides, it can thrive under poor growing conditions. The most important growing requirement for bearded iris is good drainage. It does not tolerate wet soil or standing water, which causes its rhizomes to rot. It prefers full sun and moderately dry soil for prolific blooming. Bearded iris grows best in United States Department of Agriculture hardiness zones 3 to 10. At maturity, iris can reach 36 inches tall. Many cultivars of iris exist, which offer blooms in a rainbow of colors and bi-colors. When planting new iris rhizomes, place them in a well-drained location and set the rhizomes slightly above the soil line. Do not cover the top of the rhizome with soil or mulch. Once established, iris spreads by rhizome roots.

Bee balm (Monarda didyma) thrives in full sun or part shade and is tolerant of road salt. Planted as a border along walkways or streets, bee balm typically grows 2 to 4 feet tall at maturity. As a hardy perennial, bee balm grows best in USDA hardiness zones 4 to 9. Similar to the rhizomes of irises, bee balm also requires well-drained soil. Mounds of green foliage present blooms in red, lavender, purple, and pink from June to August. Abundant blooms cover the plant and offer gardeners a resource for cut flower bouquets. Deadheading is encouraged to promote blooms. The University of Illinois instructs growers to divide the rhizomes of bee balm every three to four years to maintain plant health and vigor.

Gardeners treasure the daylily (Hemerocallis spp.) for its versatility and hardiness. While the daylily tolerates road salt, it also requires well-drained soil, similar to iris and bee balm. Daylily blooms best in full sun but can remain vigorous in partial shade. Botanists recommend this perennial for USDA hardiness zones three to nine. Over 100 cultivars of daylily offer gardeners a wide selection of attractive bloom colors and bi-colors. Providing a long blooming season, butterflies enjoy daylily flowers from May to September. Spreading by their rhizomes, gardeners must divide daylilies every two to three years to encourage growth and new blooms. Growers who deadhead spent blooms will enjoy more flowers throughout the summer.

Garden phlox (Phlox paniculata) is a hardy perennial that's impervious to road salt. This tough plant grows best in full sun. The woodland phlox (Phlox stolonifera) is a variety that enjoys shade. Recommended for USDA hardiness zones 4 to 8, garden phlox can reach 4 feet tall at maturity. For a groundcover, however, gardeners can plant creeping phlox (Phlox subulata). Providing adequate water with good drainage will keep all varieties of garden phlox blooming for years. As a heavy feeder, it must be fertilized regularly. The mounded upright foliage, full of colorful blossoms, attracts butterflies during the blooming season from June to September. Many solid-color and bi-color flowers are available with different cultivars of garden phlox.