The ideal container must be large enough to hold a substantial amount of soil. It should have good drainage facilities through holes or other openings at the bottom or sides, though this is not absolutely necessary. It must not rust, at least in a single season, and it should have a wide enough base to rest firmly wherever placed. Besides, it ought to be heavy enough to withstand average winds. In severe storms, movable containers can be shifted to temporary safety.
Resistance to rot is another requirement. Wooden containers-except those made of rot-resistant redwood, Western cedar, and Southern red cypress-will need to be treated with a wood preservative. Except for permanent containers, movability is another feature of the portable garden. Large boxes and planters can be fitted with wheels, and garden centers have redwood tubs that rest on platforms with wheels. A hole in the platform corresponds to the hole in the tub. Large containers without wheels can be pushed on iron or wooden rollers by two or more persons.
Common unglazed clay pots make good starters because they are readily available and go well with all kinds of plants. Made of natural clay, they acquire a neutral color with age, even though they are harsh orange-red when new. One gardener gives them a mellow look by dunking them in a tub of manure water. On the other hand, clay pots become dirty with accumulations of white fertilizer salts and mosses, but they are easily cleaned by scrubbing with a stiff brush and sudsy water.
Unglazed clay pots are inexpensive, so you can keep
a supply on hand. Since they are easily broken, you must guard them against wind, pulled garden hoses, and dogs. Place them at a safe distance from pedestrian traffic on steps, walks, or other passageways. Stained small pots can be broken into pieces for drainage material. Clay pots vary in size and ornamentation. The large decorated types, planted with lemons, oranges, and oleanders in Italian villa gardens, are also obtainable in this country.
Porous unglazed clay pots insure good aeration and proper drying out of the soil. Yet they often dry out too quickly, more quickly than glazed or wooden containers. In hot weather, plants may require watering in the morning and again in the evening, especially if they are pot bound. Actually, clay pots can lose twice as much moisture through their sides as through the soil surface. A properly prepared soil, with humus or other organic material plus a mulch of peatmoss or pebbles, will cut the loss of moisture. For cacti and succulents these pots are ideal.