1272 Solidago sempervirensCommon Names: seaside goldenrod,saltmarsh goldenrod Family: Asteraceae (aster Family)
Reaching a height of up to 8 ft (2.4 m), seaside goldenrod is our largest goldenrod. The basal leaves are oblong, to 16 in (40 cm) in length, and have stems (petioles). They are persistent. Leaves on the upright unbranched stalk are shorter and lance shaped, and the uppermost ones lack petioles. The stalk, stems and leaves are essentially hairless; compare this to other common roadside goldenrods, such as sweet goldenrod (S. odora), and common goldenrod (S. canadensis) which have short hairs on the stems, leaf undersides and leaf margins. The upper part of seaside goldenrod dies in winter, leaving a conspicuous and easily recognizable brown stalk with whitish leaves and a dried brown flowerhead. Only the basal rosette of leaves remains green. The roots are shallow and send out numerous rhizomes to start new basal rosettes that will give rise to next year’s stalks. One plant soon grows into a cluster of plants. The bright yellow flowerheads are dense spikes, and larger than any other goldenrod species.
Solidago sempervirens occurs near the seacoast from Quebec and Ontario all the way through the Atlantic and Gulf coastal states around to Texas. It occurs also near the Great Lakes from Pennsylvania to Michigan and Illinois. Natural occurrences of seaside goldenrod are almost always within a few miles of the Atlantic or Gulf coasts or the shores of the Great Lakes, but there is a scattering of more inland populations. Along the coast, seaside goldenrod grows on blowouts, dunes, and grassy transition areas. It often occurs with other dune plants such as switchgrass (Panicum virgatum), salt meadow cordgrass (Spartina patens), and (in the southeast) sea oats (Uniola paniculata).
Light:Seaside goldenrod is at its best in full sun, but can tolerate partial shade. Moisture:Grow goldenrod in well drained, poor to moderately fertile soil, preferably sandy. Not surprisingly, since it grows on sand dunes, seaside goldenrod is (once established) tolerant of drought. It grows like wild fire in rich, fertile soils with plenty of moisture. Hardiness: USDA Zones 2 - 10. Propagation: You can divide the roots and break off new plants along the rhizomes, but you probably won’t need to. The seeds germinate readily as soon as they ripen. In fact, they probably do not remain viable for very long after their first year. Expect a few seedling to pop up here and there outside your original planting.
American gardeners just don’t appreciate goldenrods as the Europeans do. Maybe it’s because Americans think goldenrods cause hay fever (they don’t), or maybe it’s because goldenrods are so abundant and weedy along roadsides and in abandoned fields, that there can’t be anything special about them.
Gardeners who appreciate seaside goldenrods plant them in semi-natural flower beds and butterfly gardens where the plants can spread and even fill up the bed, but where they can be kept in bounds with a lawn mower. The richer the soil, the more goldenrod will thrive and spread, so it’s best to use them in sandy, well drained soils and not to fertilize.
Seaside goldenrod is used for erosion control and stabilization projects on dunes and disturbed, sandy soils, even old mines and quarries. It is tolerant of drought, salt spray, and salty soils, and recovers quickly from fire. Seaside goldenrod blooms in the fall and late summer when butterflies are at their maximum abundance. This species is especially important to migrating monarch butterflies as they embark on their winter vacation to Mexico. Various kinds of wasps overwinter in galls on goldenrod stalks and these provide a food source for overwintering birds. Remove the flowerheads right after blooming to prevent seeding unless you want your goldenrods to spread.
There are around 150 species of goldenrods, with most occurring in North America and a few in South America, Asia and Europe. Solidago sempervirens was first described in 1753 by none other than Carolus Linnaeus, the father of plant and animal taxonomy.
Goldenrods are much more popular as garden flowers in Europe than they are in the New World, even though most species originally came from North America. European horticulturists have created numerous goldenrod cultivars and hybrids, most of long-forgotten parentage, a few of which can be found on this side of the Pond if you look. Clearly, American gardeners need to discover these beautiful, carefree flowers for fall color, attracting butterflies and cutting.
Goldenrods do not cause hay fever! Goldenrod pollen grains are large and sticky so that they can be transferred from stamen to pistil by insects. Plants with tiny pollen grains, such as ragweed, oaks and pines, produce great quantities of pollen that blow on the wind and get in people’s faces. Ragweed (Ambrosia artemisiifolia), which blooms at the same time and in the same sorts of places, as goldenrod, is the menace that causes millions to sneeze and cough every autumn.
Be warned: Seaside goldenrod can be invasive on rich soils. Have a plan to keep it in check.
Steve Christman 9/27/16