Care for Container Plants
The container garden is really easy to care for. However, since plants are more prominently displayed than in the garden, they require regular attention to keep them looking their best. Enough water is most important. To keep plants neat, remove faded flowers and yellow leaves as soon as they appear. If you go over your plants a little each day, it is easy to keep them well groomed. Some kinds, like fuchsias, drop old blossoms, which must be picked up by hand or with a small broom and dust pan. Also, keep sweeping up fallen leaves. When geranium blossoms fade, remove them with a firm snap of the fingers or with pruning shears or scissors. Cut off faded petunias to prevent seed formation. Do the same for marigolds, verbenas, snapdragons, zinnias, stocks, and other annuals as well as hardy flowering trees and shrubs, tropical plants, perennials, and bulbs.
Pinch and Prune
Some plants need pinching to shape them and prevent legginess. Cut tips from English, German, and Kenilworth ivies, variegated vinca, and other trailing plants to make them short and bushy. This is more important with plants in containers on terraces and other paved surfaces. Also snip shoots of petunias, fuchsias, snapdragons, marigolds, browallia, and other annuals. Some perennials, like phlox and fall asters, remain shorter and produce smaller but more numerous flower heads if tips are pinched once or twice in the late spring or summer. This practice delays blooming, thus extending the flowering season.
Woody plants need regular pruning and clipping. With lemon, orange, oleander, Chinese hibiscus and other tender trees and shrubs, cut out dead branches and prune to open up and shape. Do the same with hardy, woody plants. For formal effects, shear yews, hollies, arborvitae, boxwood, pittosporum, and sweet bay after new growth has hardened. Jagged tips may be cut off at any time of the year.
Water With Care
The importance of proper watering cannot be stressed enough, since container plants that are exposed to wind and sun dry out quicker than those in the ground. There are no exact rules about watering. You have to become acquainted with the needs of various plants. The best way is to examine them daily and water when the surface of the soil begins to look dry. Feeling the soil will also help you determine moisture needs. How much and when to water will depend on the kind of plant and soil, the type and size of container, and the amount of exposure to sun and wind. Climate and the weather also play their part. During hot spells, most plants need daily watering, except those in small clay pots, which may require it twice.
Some plants, like fuchsias and tuberous begonias, wilt when dry, but geraniums and succulents are not so sensitive to neglect. On the other hand, it is good to let soil dry out a little between waterings. This prevents the soil from turning sour. Since unglazed containers dry out quickest, watch them more closely. Wooden tubs, window boxes, and planters dry out more slowly; metal is the slowest of all. Groups of plants in large containers keep moist longer than single specimens. Groupings of plants, arranged close together, shade one another and help prevent excessive moisture loss.
Ways to Water
There are several methods of watering. If you have many containers or large ones, depend on the hose, allowing water to flow through slowly and gently. Water small pots with a watering can that has a long spout. When plants are grouped closely, set up a sprinkler or hose with a fine spray nearby, allowing it to run for a long while, until soil is soaked. In California, where large containers are common and where summers are dry, a permanent apparatus is often set up for watering trees and shrubs and flowering plants with just the turn of a faucet. With geraniums and petunias, avoid sprinklers which spot blossoms.
One thing is certain; you must not depend on rain. Even heavy showers deposit a surprisingly small amount of moisture, and unless rains are frequent and lengthy, you must do your own watering. Window boxes and other containers near houses or under trees can stay dry in spite of an all-day downpour. Though it is essential to give enough water, it is equally important not to overwater and so cause root rot. Over-watering also prevents aeration of the soil, and causes it to turn sour. One good method is to set containers, if not too large, in a basin or pail of water for several hours, or until the surface of the soil feels moist. Or immerse the pot in a tub or large barrel of water and leave it there until air is eliminated and the bubbling stops. The best general rule is to soak soil thoroughly when you water and then allow it to go just a bit dry before you water again.
If you go away for long periods during the summer, give the container garden serious thought before making it a project. On the other hand, you can enjoy both holidays and plants if you are absent for only short periods. The best safeguard is to entrust your plants to a responsible friend. Some neighborhoods employ handy men for this, as does Beacon Hill in Boston for its extensive window-box project. Landscape gardeners will come to water, as will nurserymen, who have more time for this during the quieter months of summer.
Several devices can be practiced. One is to arrange smaller containers in boxes of peatmoss, sawdust, or soil, which has been well soaked. Then there is the pot-in-pot method, whereby small pots are set in larger ones, with moist peatmoss inserted between. Some enthusiasts even take their plants with them when they are vacationing.
About Every now and then you will want to shift plants around to accommodate their needs. On hot, windy days, move into the shade exposed pots that are subjected to reflected heat from stone walls, concrete walks, or paved areas. Remember, too, that hanging baskets dry out the quickest. In the event of a violent wind or rain storm, move containers to safety.
A good feeding program will result in healthier plants with more bloom. In the confined soil areas of containers, plants utilize nutrients sooner than they do in the garden; so, in general, feed plants every two weeks with a balanced chemical fertilizer, following directions on the package. For more immediate results, apply liquid fertilizer. Some plants are voracious and will need more frequent feeding. Foliar fertilizer can be applied as a supplement.
Containers on pavements, patios, walks and driveways will not need saucers and are better without them, for water will run out freely. However, on other surfaces, as painted porch floors or tables, saucers are needed to prevent staining. You can use plastic saucers, light, non-breakable and inexpensive, in black, gray, green, rose, or red. Avoid clay saucers, since their penetrating moisture leaves circular, whitish marks. When saucers are used, be careful that pots do not stand in leftover water for any length of time.
From time to time, clean saucers with a stiff brush and soapy water. Containers will also require washing out. Painted tubs that stand on or near plant beds become spattered with mud during heavy rains or during sprinkling. If the mud is allowed to dry, it will rub off easily with a piece of cloth or your fingers. When you plan a party, it is a good idea to give containers a quick going-over with a damp cloth or sponge to make them sparkle.
When to Repot
As plants become pot bound, they will need shifting to larger quarters. This applies to such permanent plants as trees and shrubs, but not to annuals or temporary kinds. Though spring and fall are the best times to repot, it can be done any time if roots are not disturbed. Usually, the rule is to move a plant to a container of the next larger size. If a plant is in an eight or nine-inch pot, shift to a ten-inch size. If it is already in a ten-inch size, supply a tub that is just an inch or two wider in diameter.
As a rule, tubbed trees and shrubs can stay in the same container for several years if fed regularly and if some soil is removed from the top annually and replaced with fresh mixture. Some actively growing plants may require moving to large containers every two years. On the whole, avoid overlarge containers since the soil will hold too much moisture for plants to absorb it quickly. Overpotting tends to promote a water-logged condition.
Winter care varies with climate and types of plants. Discard annual and temporary kinds and bring house plants indoors or to a greenhouse. Palms, gardenias, and camellias in the South and yews, arborvitae, and pieris in the North can be left outdoors. In some cases, they will require shifting to less exposed spots and may even need covering with burlap, plastic film, or evergreen branches to guard against windburn or sunscald. Spraying the tops of evergreens with plastic wax in the early winter will cut down on evaporation. Remember that container plants in the winter still need water, but if soil freezes hard, wait for periods of thaw.
Where temperature drops to zero and below, soil will freeze solidly and many hardy plants may be killed. This is due, not so much to the cold, but to frozen soil, which does not allow tops to draw moisture, though they are still constantly transpiring. In below-zero regions, hardy evergreens, arborvitae, Japanese yew, hemlock, pines, and Douglas fir, if planted in containers with sufficient soil, will survive winters out of doors.
Where temperatures drop only to twenty degrees above, the choice of plant material is greater, extending to pieris, rhododendrons, azaleas, false cypress, firs, English and Korean boxwoods, cherry laurel, leucothoe, mahonia, and climbing euonymus. English ivy, myrtle, and pachysan-dra are three low evergreens that are reliably hardy. For milder climates, with little or no freezing, the choice is almost limitless, including camellias, oleander, hibiscus, crotons, poinsettia, aucuba, pittosporum, nandina, podo-carpus, acacias, palms, bougainvillea, and ficus, not to mention many annuals. In sections where soil does not freeze, watering is no problem in winter. Unless rains are frequent, water with the hose, sprinkler, or watering can. Depending on climate, sweet bay, oleander, orange and lemon trees will need the winter protection of a cool greenhouse, a well-lighted shed or unheated room where above-freezing temperatures can be maintained. During this resting period, give just enough water to prevent soil from drying out.
Winter Preparation for Spring
The winter, too, is the time to clean and prepare containers for the next season. Bring indoors-into cellar, shed, tool house, garage, attic, or spare room-easily moved containers, as this will help preserve them. Especially is this true of materials that deteriorate, among them several kinds of wood. Clay or glazed pots will break if not emptied of soil, which freezes and thaws, creating pressure against the sides. Valuable glazed or porcelain containers should never be left outdoors, with or without soil.
Empty soil from clay pots before bringing them in and then clean them with a stiff brush and hot water plus a detergent. Empty the soil from wooden tubs and boxes as well and scrub surfaces with soap and water. Paint or stain them later when they are thoroughly dry. Plant stands, wall brackets, baskets, wooden hanging baskets, small window boxes and other containers should be cleaned late in fall and made ready for the coming season well before planting time in spring. Large planters, boxes, and window boxes, which are not easy to move, must be left outdoors. However, their condition should be carefully checked before winter sets in to see whether they need bracing or a coat of paint.