Soil Mixtures and Planting
To a great extent, the success of the container garden depends on proper soil. You can have good results with soil taken directly from the garden, but even better if you take the time to prepare a proper mixture. This control of soil is where growing plants in containers have an advantage over gardening in the open ground.
Soil mixtures can also be purchased at nurseries and garden centers with special kinds available for acid-loving plants (azaleas, camellias, and gardenias) for ferns and begonias, and for cacti and other succulents. If you live in a city where garden soil is not easily obtainable or if you grow only a few plants, it is practical to buy a prepared mixture.
SOIL MIXTURES All-Purpose
2 parts good garden loam
1 part sand
1 part peatmoss or leafmold or other humus
1 teaspoon bonemeal for each 5-inch pot of mixture (5-inch potful to each bushel)
For Acid-Lovers (Azaleas, Camellias, Gardenias, Heathers, etc.)
2 parts good garden loam
2 parts sand
2 parts acid peat
1 part leafmold
1/3 part old manure or 1/2 part dehydrated manure
For Fine-Root Plants (Begonias, Ferns, African Violets, Gloxinias, Christmas and Orchid Cacti, etc.)
2 parts good garden loam
2 parts sand
2 parts leafmold or peatmoss
1/2 part old manure or 1/2 part dehydrated manure
For Bulbs (Hyacinths, Daffodils, Tulips)
2 parts good garden loam 1 part sand
1 part leafmold or peatmoss 5 inch pot of bonemeal for each bushel
For Cacti and Succulents
2 parts good garden loam
2 parts sand
1/2 part leafmold or peatmoss
5 inch pot of bonemeal for each bushel
5 inch pot of finely ground limestone for each bushel
For Orchids and Bromeliads
6 parts Osmunda fiber
1 part of 1/2 -inch charcoal
The container should be filled with 1/3 drainage material. If Osnlunda fiber is not available, use equal parts peatmoss, sand and granulated charcoal.
PLANTING When you are ready to mix ingredients, be sure the soil is damp and workable. To determine this, take a handful, squeeze it and allow it to drop. If water comes out, it is too wet; if it breaks apart, it is too dry. But if the lump of soil retains its shape or cracks just a little when it is dropped, it is in good condition to work.
Be certain containers are clean when you start. Soak used or new clay pots overnight so they will not draw moisture from soil after planting. Clean dirty clay pots with a stiff brush and hot, soapy water.
Though redwood, cedar, and cypress containers may be left natural, they may also be stained or painted. First clean the surfaces then apply one or two coats of stain or paint. Let dry completely before planting. Concrete, metal, plastic, fiberglass, and similar materials all need cleaning.
Suit Plants to Containers Consider the shape of each container, its color, and texture in relation to the color of flowers and foliage and the present as well as ultimate size of each plant. Don't choose material that is too small, and if you want a group of plants for a large container, select one tall specimen for the center to give height and scale.
In low pots or bulb pans and in tubs, use low-growing plants-fancy-leaved caladiums, petunias, verbenas, Ian-tanas, ageratum and wax begonias. Hyacinths, tulips, and daffodils are also appropriate. In tall containers, plant specimens of geraniums, heliotropes, coleus, balsam, dwarf dahlias, fuchsias, and marguerites. Reserve large tubs and boxes for trees and shrubs.
Keep in mind the form of plants, particularly the evergreens which stand out boldly in winter. Rounded types, as clipped yews or globe arborvitae, look well in angular containers. Hollies or yews, sheared into squares or pyramids, look better in circular tubs. This contrast of the curving with the straight always gives interest.
How to Pot The first step in potting is to place sufficient drainage material in the bottom of each container so that water can pass through freely. An inch or two of flower pot pieces (rounded sides up), or chips of brick or flagstone, pebbles, gravel, small stones, or cinders can be used. The larger the container, the larger the pieces should be. Some gardeners spread a piece of coarse burlap and a layer of sand over large drainage pieces. A layer of Vermiculite or sphagnum moss over the drainage material is also fine to keep soil from clogging holes.
Above the drainage, spread a layer of soil, the amount depending on the size of the container and the root ball of the plant. Place the plant in position so that the surface of the soil will be an inch (more for big plants) below the rim of the container. This space is needed to hold water.
Fill soil in around the roots, firming gently with your fingers or a piece of wood so as to eliminate air pockets. Add more soil and firm, but do not make the soil too tight for fine feeding roots must be able to penetrate it with ease.
Finally, water plants well, let them drain. If water passes through the pot very rapidly, press soil again to firm it. If the soil holds water too long, loosen it a little.
Place container plants in a sheltered spot out of sun and wind for the first week or so while they make new root growth and adjust to new conditions.
When your permanent trees, shrubs or perennials grow too large for their containers, shift them to bigger ones. Water the night before so the soil will be moist for transplanting. Dry soil tends to break apart, except on root-bound specimens. To remove most plants, invert the pot over your left hand and tap the pot rim sharply on a step or table or slip a knife around the inside edges. Turn larger plants on the side, knock the pot to loosen the plant and remove with a firm, gentle pull.
Handling Large Plants Planting large specimens purchased in temporary containers is a more involved process. If they are in baskets or boxes, these can be broken or torn apart, but be careful not to disturb the roots. Tins must be opened with tin cutters. To remove plants, put the cut containers on their sides and pry steadily at the ball of soil gently in order not to break it.
All container plants benefit from a mulch spread evenly over the surface of the soil. This will keep the soil cool and moist and weeds under control. Use peatmoss, sand, gravel, stones, pebbles, buckwheat hulls, or Vermiculite. One of these will also give an attractive appearance but since the mulch conceals the soil, it is more difficult to determine when to water. Test by poking a finger through the material to touch the soil.
Though drainage holes are recommended, they are not essential. I have seen flourishing geraniums and wax and tuberous begonias in jardinieres, jugs, and iron kettles with only a thick layer of pebbles, broken flower pots, cinders, or coarse sand spread at the bottom to catch water. Of course, what is important here is a sensible program of watering rather than the presence or lack of drainage outlets.
Pointers for Planters In the case of planters, again make certain drainage facilities are good. Usually there are holes at the base or sides. For best results, every four square feet should have a two-inch drainage outlet.
Planters attached to buildings are often open at the base. As with other containers, before filling with soil, spread a thick layer of broken flower pots, crushed bricks or coarse gravel over the bottom. With large-sized planters, this should be six to eight inches thick with a layer of straw or sphagnum moss above to prevent soil washing. Planters require day-by-day care to keep plants at their best. This means pruning, staking, spraying, feeding, and more particularly watering. Planters adjoining walls dry out quickly, especially where heat is reflected from brick, stucco, or concrete. Often planters are located under overhanging roofs or broad eaves. Wherever they are, do not depend on rain, but apply the hose as often as needed, which is usually daily and sometimes more often. Remember to have planters in factories, offices, and public buildings watered on week-ends and through vacation periods.
Planting the Strawberry Barrel You can make your own strawberry barrel from a nail keg (which is easy to handle) or a barrel. A 55-gallon molasses barrel is fine for your purpose.
With a keg or barrel, first bore five or six half-inch holes in the bottom for drainage. Then make two-inch holes, in alternate rows, around the sides, starting six inches from the bottom. Keep the holes six to eight inches apart. If you want the wood natural, treat it with a non-injurious preservative, or paint it with a light color to set off the foliage.
To enable all plants in the barrel to get water, insert a drainage pipe in the center. But first, spread broken crock or brick over the bottom with a two-inch layer of gravel on top. Then hold a piece of rolled cardboard upright in the center of the barrel and fill with sand. Or take a downspout, with several quarter-inch holes bored in the sides, and hold it in position in the center while you fill it with sand.
While holding the cylinder with one hand, with the other spread potting soil over the drainage layer and up to two inches from the lowest row of holes. Tamp to firm. Then add more soil just up to the holes. The cylinder should now stand alone while you insert plants through the holes. Spread out their roots and cover with soil.
Repeat to the top of the barrel, setting plants in the holes and tamping soil so it will not settle later. At the top, place more plants around the drainage cylinder, spacing them about six inches apart.
Pull out the cardboard when all the planting is finished. The sand will then act as a drainage outlet. However, if you used a perforated cylinder, let it stay. Then when you're watering your strawberry barrel, pour a little water right into the cylinder to reach the plants at the base, and pour more over the top around the cylinder.
Besides fruiting strawberries, you can grow strawberry begonias, pick-a-back plants, episcias, chlorophytums, and small-leaved English ivies. When plants get rampant, remove some of the runners so the surface of the barrel will show a little. In hot, sunny positions, ivy-leaved geraniums, trailing lantanas, verbenas, cacti, and succulents will thrive. Annual sweet alyssum adapts itself well to this novelty container, and a combination of white, pink, and lavender varieties is a pleasant sight.
If you live where there is winter freezing, move the strawberry barrel to a cool, frostproof place. Alternating freezing and thawing is harmful, especially with the glazed jars, which crack and break. If you have a cool, well-lighted window for the barrel, plants can be left in place. Otherwise, you must remove them and plant them again in the spring.