| By Dr. William C. Welch
Professor and Landscape Horticulturist Texas AgriLife Extension Service Texas A&M University |
Every year about this time I wonder why I planted so many pots with plants that require frequent watering. There really are some excellent alternatives that offer year-round interest, color and sustainability. First, let’s explore the role of containers in our landscapes. Potted specimens offer a way to feature the plant. Think of them as accessories in the landscape. The containers themselves can either be a strong visual statement or be more utilitarian in order to make the plant the main focus.
Container gardening can be modest or grand in scope. One of the most impressive container gardens I know is the Orangery at Versailles near Paris. For several hundred years large specimens of citrus, olives and other tender plants are moved out into the garden during the summer months. This required some heavy lifting. When I plant something too large to easily transport into my garage for the winter, I remind myself that I don’t have a “staff” or facilities to handle them. My largest container is an 18”-diameter pot of plumeria. It is happy to go dormant on a workbench in the garage and requires no watering till I put it back out into the garden in April. Containers can also be very simple. One that comes to mind is three recycled washpans displayed on a cut stump and filled with old-fashioned petunias in a rural Arkansas garden.
From a design perspective, containers can give a space structure. Structure is sometimes considered “the bones of a garden.” Good bones are a way to have year-round continuity in the landscape. Large containers or masses of smaller ones of similar color and form are a way to have the garden look good year-round. Containers can have significant impact at entrances and are a great way to accent axis lines. Good designers tend to use large containers rather than small ones.
In recent years I have enjoyed the beauty and practical aspects of some of the succulents. Succulents are plants with thick, fleshy and swollen stems or leaves that are adapted to dry climates. Cacti are succulents but sometimes not horticulturally included with them. I prefer succulents that can withstand our winter as well as our rentlessly hot summer temperatures.
Following are a few favorites. You may have to look for them in the nursery trade or find a fellow gardener who will share. One of the assets of all of these plants is their ease of propagation. Stem or leaf cuttings usually root within a few weeks. I prefer to direct-stick them in pots of professional potting mix sometimes modified with about 1/3 sandy loam soil or builder’s sand. The surface can be covered with rocks, pebbles or just allow the plant to cover the soil.
Sedum palmeri is one of the native Mexican sedums. I don’t know a common name for it, but it has performed well for me for 10 or 12 years. The plants only get 8–10” tall and that is when they are in flower, which is usually from early February through March. The rosettes of bluish-gray foliage look good all year. The yellow flowers are quite showy. They can be grown from individual leaves, but it is much quicker and easier to take stems of the foliage and plant them a couple of inches apart. If this is done in summer, the plants will bloom beautifully the following winter and spring.
Graptopetalum paraguayense, hens and chicks, is an old favorite in Texas gardens. It is another Mexican native and thrives everywhere in our state except in North Texas and the Panhandle, where it appreciates a little winter protection. The stunning rosettes of blue-gray foliage look good all year and bloom in spring with sprays of starry, white flowers. The flowers are nice, but the foliage is the main attraction. The leaves of these succulents break off the stems very easily; so it is important to handle them carefully. This is another one that can be started from stems or leaves. If you can obtain stem cuttings, arrange them several inches apart in the pot and bury the stems up to where the leaves begin.
Graptosedum ‘Vera Higgins’ is another really tough succulent. I got mine from Greg Grant. It is occasionally in the nursery trade but popular as a passalong plant and at sales like the Stephen F. Austin Plant sales each spring and fall. ‘Vera Higgins’ looks like a sedum but also like a Graptopetalum, better known as “hens and chicks.” Culture and propagation are from stems or leaves and the flowers are not really significant compared to the reddish/gray foliage.
Sedum potosinum is another Texas heirloom from Mexico. It, too, has bluish-gray foliage that forms masses and has small, attractive star-shaped flowers in spring. This is a small plant, about two inches tall, but makes an impressive pot, groundcover or edging where it can spill over edges.
Sedum acre, gold moss sedum, is known for its golden green moss-like foliage and also has showy yellow flowers in spring. It roots quickly from cuttings. All of these plants prefer a sunny location, but none require full sun.
Opuntia cacanapa ‘Ellisiana’ (Ellisiana spineless prickly pear) is a spineless form of prickly pear that makes a strong statement in the garden or in containers. Although it has none of the fearsome spines of the native form, it does have tiny, hair-like glocids that should be avoided. Both the flowers and fruit are highly attractive. The leaves and fruit are often consumed by Mexican-Americans. New plants are started by taking a leaf or several leaves and partially burying them in soil. Roots will appear within a few weeks. Once established, prickly pear can thrive on natural rainfall.
Mixed pots of succulents and grasses are another interesting possibility. The one shown was assembled in late August and photographed about a month later. In addition to the Opuntia, hens and chicks, a small clump of ‘Emerald’ zoysia and a few cuttings of large flowering purslane were combined. We created two matching 12” clay pots to serve as accents at either end of an outdoor sofa. The only maintenance has been to replace one of the pots that blew over in a 40-mile-per-hour wind this winter. We scooped up the plants and put them in a new pot, and they continue to thrive.
