Container Gardening

MARILYN H. JOHNSON iö-

CONTAINER gardening, an ancient Another solution is the vertical garden practice, is coming more and more which, however, takes time, patience, and into favor these days. It now can be seen many plants. It is portable, attractive, and in various forms and locations and may worth the extra effort. A wooden frame consist of a variety of materials, plants, first is covered with chicken wire. Then and mulches. The age-old problems of this is packed with well separated and esthetics and culture still exist, with age- dampened peat moss or sphagnum to old solutions as well as contemporary ones. receive annual plants with small root balls Plant containers today are used for a covered with soil. These should be placed variety of purposes. They can direct the almost vertically in the peat moss. If plants pedestrian traffic, provide visual barriers are applied to both sides, a freestanding and windbreaks, contribute color, texture, wall is achieved. If one side is to be set and shade, and even furnish a transition against the building wall, tar paper or between the interior and the exterior. other water-resistant material should be Plant containers, if below eye level, are placed between the garden and the build- a helpful and subtle method of controlling ing. This will keep the moisture in the pedestrian traffic patterns. The pedestrian garden and out of the building. might become instantly aware that a con- There should be a regular watering tainer garden is contributing color, but if schedule, and the garden should be the elements of color and texture are skill- dampened thoroughly. There must also fully handled, his attention will usually be a regular liquid fertilizing schedule, be captured, and he will be unaware that since the plants require nourishment in he is being guided. order to perform well. Sometimes—especially in these days of I have found the container is a very the terrace, the patio, and the roof gar- effective transition between interior and den—visual barriers are required for exterior. By repeating, with an indoor privacy, to obstruct a view, or as a wind- planter, some of the plant material which break. Container gardening is one way of I have used outdoors, a bond is created controlling these problems. A row of tall- between the two. growing material of the columnar type, Container gardens are flexible and planted in a long planter or in identical versatile and can be used in a variety of individual tubs, is one way to acquire a locations, such as entrances and exits of strong and unified effect (A). buildings, as freestanding tubs on streets and terraces, as elements in exciting roof (A) íííi 1ÍJ tí^ Marilyn H. Johnson is the Landscape Archi- tect at the National Arboretum, Crops Research Division, Agricultural Research Service. She has designed many container gardens for the Agriculture Department.

231 gardens, as vertical garden walls, and as areas in the paving (C) and in fixed window boxes. They can be used in raised areas (D), the container gardens groups to enliven interiors, and they can will, of course, be stationary. be used as single features, such as bonsai More and more contemporary buildings (B), inside and outside. seem to be surrounded with expanses of Container gardens, found in a variety concrete which, in the summer, produce a of forms and locations, fulfill many pur- tremendous amount of reflection. Ways to poses. Some can be portable, such as boxes, combat this problem include use of free- tubs, pots, and hanging baskets. Some can standing containers (E and F), opening be made even more mobile with the addi- of planting areas in the concrete, or raised tion of concealed casters. In fixed open planting areas—all to accommodate trees, shrubs, or bedding plants. (E)

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Perhaps the one element that makes the Since the same design principles apply, greatest contribution to any garden re- equally, to the small or portable garden as gardless of size is the careful thought (or to the larger, stationary one, the plan is of design) devoted to it. Some of the com- a primary importance. Within the plan, ponents of design are balance, scale, color, consider balance first. For a successful texture, dimensions, and harmony. planting, it plays an important, but unob- trusive part. Formal balance (G), most (F) frequently used, is probably easier and more suitable than informal balance (H). One element which seems difficult for the layman to understand is scale. The plants, the container, and the surround- ings should be the proper size in relation- ship to each other (I). An ingredient too small in scale is insignificant, and one too large is overpowering. Center is just right.

Color can be used as a dramatic con- trast to a building if tones of a contrasting color are selected. Complementary colors can be used to accent your building. If a pleasing combination is used, it can do much to make a planting attractive. Since too many colors weaken the effect, fewer colors should strengthen it. I recommend using no more than three complementary colors and one contrasting color in any container composition.

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235-917 O - 67 - 18 Even the smallest planting should have Wood is preferable to metal because it contrasting textures (J) for variety and does not retain heat. Good containers of redwood, pine, cedar, outdoor or marine plywood can be made or bought. If you are building your own, allow for drainage and moisture absorption. Use brass bands or brass screws as fasteners to avoid rust. Most woods should have either paint or a preservative coat—nontoxic to plants— inside and out, for durability. Redwood, rustic in feeling, is really not suitable for urbanized areas or for sophisticated settings. Attractive garden containers can be interest. I would suggest two for a small made by facing plywood with solid color garden container and more for a larger plastic material—the kind which is used planting. As with color, however, do not on kitchen counters. introduce too many textures, since this A concrete container, if not massive or tends to weaken rather than to strengthen heavy in appearance, can have its per- the composition. sonality established by the plants that it There should be a variety of heights as holds. well as textures and colors in a planter. If Transite tubing, cut and painted, makes the planter is to be seen primarily from an attractive container (K). So do painted the front, I suggest using three heights with the tallest in the back, the inter- mediate one in the middle, and the low or trailing type in the front so as to achieve (K) a softening effect. If the container is free standing and can be seen from all sides, I would place the tallest plants in the center, the intermedi- Plastic Mulch ates around them, and the low or trailing sheet ones near the edge of the planter. Transite The pleasing relationship of the integral tubing parts—balance, scale, color, texture, and Wooden dimension—results in a highly desirable blocks situation which is called harmony. The choosing of materials for your con- tainer garden is limited only by your chimney flue tiles. Both can be obtained imagination. In addition to the traditional from your local terra cotta tile dealer. Use materials like wood, terra cotta, ceramic, different heights and diameters for the and concrete, others—rope, Transite tub- pleasing compositions that will result. ing, plastics, and aggregates—can be both A mulch helps considerably whether very serviceable and attractive. indoors or out and gives a garden a fin- But one important question should be ished appearance. Many mulches con- asked before building or buying contain- tribute organic matter to the planting and ers. What is your container supposed to most help to retain moisture and protect achieve? After you have decided its pur- the plant roots from heat. Since mulches pose, you can select your materials. But come in a large variety, you must choose first, study them and be sure they are a for your own particular purpose. suitable choice. Perhaps the materials Wood chips are rustic, good for large have to blend with a certain type of archi- areas, and coarse in texture. They are tecture. If so, the proper choice will result suitable for rustic architecture or for an in a charming composition. outdoor rural setting.

234 Peat moss and tanbark are both good, the plants. They, like all other living and both are dark in color. Peat moss things, have many requirements. Every possesses the finer texture of the two. Its plant must have light, food, and water to texture and richness of color make it thrive. A good soil mixture and spraying suitable for more delicate architecture and program and good drainage contribute for urban settings, but it also may be used greatly toward healthy plants. for rustic settings. A regular fertilizing program will do River washed stones, or slag, make much to make planting succeed. I would attractive mulches although they do not recommend, in addition to fertilizer in contribute organically to the planting. the original soil mixture, that a liquid These, I would say, also are more suitable fertilizer be applied at regular intervals. for the refined, sophisticated setting (L). Since requirements vary according to the soil mixture, geographical location, and (L) type of plants, it would be wise to consult X^ your local garden center. Here, too, a spraying program and precise proportions for soil mixtures can be obtained. The two most common complaints of portable container gardens, too much or too little water, can be solved in many m ways. The container should be slighdy raised above the ground to provide air- space. There should also be drainage holes in the bottom of the container, and they should be covered with large pieces of broken crockery. In the window box, a 1-inch layer of broken crockery should then be placed over the entire bottom surface. In a larger container, the entire The choice of plant materials can do bottom surface should be covered with much to establish the success of the con- gravel 1 inch in diameter to a depth of tainer garden. It can be made to look about 3 inches (M). For all types of con- delicate, substantial, heavy, gaudy, gay, tainers, I place a double thickness of colorfully pretty, severe, plain, unclut- porous fiber glass over the material. This tered, sophisticated, or whatever is desired. I have found (especially with in- door planters) that it is wise to have extra (M) plant material to rotate and freshen the appearance of the container. There are so many bedding plants which will not only live, but thrive in container gardens that there are almost no limits to the choice. The garden can be x" planted year after year with almost no repetition of plants. A good book, or garden center, will usually provide the Soil needed information, both for interior and Mulch ■ mixture exterior plants. Those interested in bonsai Holes will require special books and informa- 2 layers ] ^■ covered tion about this subject. of porous with No matter how much attention you pay fiberglass broken to the esthetic elements and the plant crockery material, your container garden will not 1" dia. Air flourish unless you consider the culture of gravel space

235 helps to keep soil from washing out and flowers or seed pods which will extend the discoloring the surrounding sill or ter- bloom of many plants. Since they react race. Raised beds have a built-in drainage quickly to heat, wind, and reflection, the system, of course. trees and shrubs must obtain proper The best soil mixture, usually a light moisture. Watering should be stopped in one, is placed directly on top of the fiber freezing weather, but can be resumed on glass. Although the components will be the mild winter days. determined by the plants you intend to Although container gardening has been use, almost all mixtures contain some practiced since the time of the ancient combination of loam, sand, peat moss or Egyptians and has flourished over much leaf mold, bonemeal, and well-rotted of the world, those of us in the cooler manure or dried cow manure. climates of this country are still in the Culture for plants in container gardens pioneering stage. With the trend toward is the same as for plants growing under modern architecture and the growing more normal conditions—with added popularity of beautification, the interde- problems. Most vigorously growing bed- pendence of building and landscape ding plants benefit from cutting or pinch- effects is giving us more and more experi- ing back and from the removal of dead ence with container gardening.

For more information: flower {Godetia), heliotrope, candytuft (Iberis), • Consumers All, the 1965 Yearbook of Agri- sultan's balsam (Impatiens (dwarf)), lantana, culture. "Basic Points of Landscaping," pp. lobelia (trailing), double French marigold 279-282, Marilyn H. Johnson. (dwarf), nasturtium, nicotiana (dwarf), blue • Agricultural county extension agent and cup flower {Nierembergia), petunia (trailing), department of horticulture at your State phlox (dwarf) {Phlox drummondi nana com- university. pacta), rose moss {Portulaca), wishbone flower • Various horticultural handbooks of plants {Torenia Fournieri), verbena (dwarf), peri- and gardens, Brooklyn Botanic Garden, Brook- winkle {Vinca), pansy {Viola cornuta), and lyn, N.Y. 11225. zinnia (dwarf). • Various Sunset Gardening books by Lane Suggested colorful plants for containers: Books, Menlo Park, Calif. Begonia, begonia (tuberous rooted), chrysanthe- • Bonsai information from Bonsai Society, mum, geranium, and geranium (ivy-leaf). c/o New York Botanical Garden, New York, Suggested textured plants for containers: Stone- N.Y. 10458. crop {Sedum) and hens and chickens {Sem- Suggested trees for containers: Cornelian- per vivum). cherry {Cornus mas)^ Washington Hawthorn Suggested foliage plants for interiors: Small {Crataegus phaenopyrum), honeylocust (Gledit- plants—Aglaonema varieties, grape ivy {Cissus sia triacanthos varieties), crabapples {Malus {Vitis) rhombifolia), Dracaena varieties, jade species and varieties), sweetgum {Liquidambar plant {Crassula argéntea {arborescens)), Boston styraciflua), and Japanese pagodatree {Sophora fern {Nephrolepis exaltata bostoniensis), heart- japónica). leaf philodendron {Philodendron oxycardium Suggested shrubs for planters: Glossy Abelia {cordatum)), and English ivy {Hederá helix). {Abelia grandiflora) y camellias, Japanese holly Large plants—^Madagascar dragon tree {Dra- {Hex crenata varieties), crapem5rrtle {Lagerstroe- caena marginata), figs {Ficus varieties), split leaf mia indica) i drooping Leucothœ {Leucothoe philodendron {Philodendron pertusum), large catesbaei), Oregon hoUygrape {Mahonia aqui- leaved Mexican breadfruit {Monstera deliciosa), folium), Japanese Pieris {Pieris japónica)) African pine {Podocarpus macrophylla), mock Japanese Pittosporum {Pittosporum tobira), Por- orange {Pittosporum tobira), and spineless Joshua tugal-laurel {Prunus lusitanica), azaleas, and tree {Yucca elephantipes). rhododendrons. Suggested plants for bonsai—^many can be Suggested annuals for containers: Floss flower used, but the most popular are species of: Maples {Ageratum (dwarf)), sweet alyssum, asparagus {Acer), hinoki cypress {Chamaecyparis obtusa), fern (trailing) {Asparagus sprengeri), ornamen- gardenia {Gardenia jasminoides), ginkgo {Ginkr tal basil, amethyst {Browdlia)i calliopsis go biloba), hollies {Ilex), junipers Quniperus), (dwarf), dusty-miller {Centaurea gymnocarpa), oaks {Quercus), pines {Pinus), cherries {Prunus), California poppy {Eschscholtzia), gazania {Ga- dwarf pomegranate {Púnica granatum nana), zania splendens)t transvaal daisy {Gerbera) ^ satin and zelkova. 236