By Dr. William C. Welch
Freelance Writer
The water’s edge is a magical place in both the natural and man-made landscape. Selecting plants to accent the water’s edge offers interesting design opportunities in our gardens. Whether it be a small pond, lake or fountain, there are many choices that add color and interest to the landscape. Calla lily, various reeds, marsh mallow, swamp rose and elephant ears are great plants that can help us transition the watery zones in our landscapes to dry land.
Seldom in any area of our cultural development is progress uniform or predictable. New personalities and ideas burst on the scene, sometimes with startling impact. So it was in the field of landscape planning. In 1841, there appeared the first edition of Andrew Jackson Downing’s Landscape Gardening. This book found instant popularity. Overnight. Downing was the founder of a new and more natural school of estate and park design. His design method became quite popular and by 1859 his new book, Theory and Practice of Landscape Gardening, could be found on almost every parlor table in the country.
Among the critical issues to success in a garden is the use of water. To quote Downing, “Cascades and water-falls are the most charming features of natural brooks and rivulets. Whatever may be their size they are always greatly admired, and in no way is the peculiar stillness of the air … more pleasingly broken, than by the melody of falling water … leaping over a few fantastic stones. [It] has a kind of lulling fascination for the ear, and when this sound can be brought so near as to be distinctly heard at the residence itself, it is peculiarly delightful.” Many of the most celebrated authors who have treated the subject of water in the landscape appear to agree that the work of artists relating to water in the garden should most represent the natural creations of nature.
There are several perennial plants that add color, textural contrast and floral beauty to the water’s edge that are all easily grown in Texas gardens.
Louisiana iris (Iris ser. Hexagonae). These irises are bred from native species primarily found in East Texas and Louisiana. They occur naturally in wetland areas but can be well grown in dryland gardens. They thrive in the water or along its edge and are useful in boggy or poorly drained areas, including septic fields and lowlands. Fertile soils are preferred and their greatest need for water is in the fall and winter, when moisture is naturally abundant.
Colors range from light yellow to blues, whites, maroons, purples, rusty reds and blends. Bloom time is early to mid-spring. They grow from rhizomes that sometimes go semi-dormant in the heat of summer. Ideal planting time is fall but most anytime will work. Winter protection is not needed, and Louisiana irises grow in every state.
Calla lily (Zantedeschia aethiopica). Calla lilies prefer partially shaded locations having rich, moist soils. They can also be grown in containers in water. Callas grow from thick, tuberous roots and various-colored forms are available. White and yellow are the most common, but I have only had success with the white form as a water plant. Callas are somewhat cold sensitive and are best grown in Zone 8 and farther south. The flowers are elegant and recur from early spring through mid-summer.
Marsh mallow (Hibiscus moscheutos ‘Lady Baltimore’). Marsh mallows are native to the swampy coastlines of Texas and Louisiana. ‘Lady Baltimore’ is a hybrid that roots easily from cuttings. These mallows may freeze to the ground in winter but are root hardy all over Texas and the South. The flowers only last one day but are spectacular and often occur in abundance. Fertile soils provide abundant flowering from mid-spring through frost. Individual plants may reach 6 to 8 feet tall and be just as wide. A mid-summer pruning and application of fertilizer promote a long season of spectacular blooms.
Spider lily (Hymenocallis liriosme). This attractive native is found in low, wet places and has bold, beautiful foliage together with striking large and fragrant “spider-like” flowers during the summer. ‘Tropical Giant’ is a large, vigorous form of spider lily that is popular throughout the Gulf Coast states. Large umbels of white flowers occur on long stems in late June and July. It grows well in clay soils and its coarse texture and bold foliage make a statement in the landscape. Propagation is by division, and cold hardiness extends through Zone 7. Foliage is usually cut back in early spring in locales that freeze.
Swamp rose (Rosa palustris var. scandens). The swamp rose is a native plant from Louisiana eastward to Florida, occurring along streams and in marshes. Its ability to tolerate wet, poorly-drained locations is rare among roses and adds to the value of the plant. The form found most often in old gardens in the South has double or semi-double flowers, which bloom in mid- to late spring. It is weeping in form and is almost thornless. It is an attractive shrub even when not in bloom. Fragrance is excellent and the soft pink flowers can nearly cover the gracefully arching limbs for several weeks each spring. Propagation is from cuttings.
Elephant ears (Colocasia esculenta ‘Mojito’). Elephant ears have long been an easy-to-grow tropical perennial in Southern gardens. ‘Mojito’ has green leaves set off by dramatic dark flecks and streaks. It grows from bulbs and thrives in sun or partial shade. Combining ‘Mojito’ with dark-purple grasses or chartreuse sweet-potato vine can add significant color and interest to the garden. While some elephant ear varieties can be invasive, ‘Mojito’ and several other fancy varieties have been bred to provide bold, beautiful foliage without having to worry about it taking over.
Horsetail rush, scouring rush (Equisetum hyemale). A tall, slender reed-type plant that grows in swampy areas. It prefers some shade and may be considered invasive. There is a rough texture to the stems that made it attractive to Native Americans for scouring. This plant creates strong, vertical interest and may have the tops trimmed to create a “hedge” effect. It is cold hardy through Zone 7.