Container Garden

A container garden grows food in a pot instead of in the ground. The pot can be almost anything that holds a growing medium and lets water out of the bottom - clay, wood, plastic, a metal tank, a cut barrel. Needing no trade skill and no structure, it is the entry point for anyone with no ground to plant in: a patio, a driveway, a balcony, a roof, or soil too poor or contaminated to use.

Everything then depends on the filling and the size of the pot. Garden soil is the wrong filling - it packs down, holds water and starves roots of air - so a light soilless mix goes in instead: peat, bark, perlite or vermiculite, with compost up to half of it, or rice hulls, sand or coir where no bagged mix is sold. Drainage holes are essential, and gravel in the bottom makes drainage worse, not better, because water gathers in the mix just above the stones. Size follows the crop, and a pot should be at least as tall as it is wide: a lettuce is content in 2 litres (2 quarts), while a tomato wants about 19 litres (5 gallons). Fruiting crops want six hours of direct sun and do better on eight to ten; leaf and root crops take some shade.

The real cost is attention. There is no soil volume to buffer anything, so a mature planting often needs water once a day and sometimes twice, faster from clay than from plastic and slower under a mulch. That watering carries the nutrients out with it, and an unfed container is exhausted in about eight to ten weeks, so feeding runs to a fixed interval: slow-release at planting, then a liquid feed every two to four weeks. Too much burns the roots and leaves a white salt crust to be rinsed through. Frequent wilting that recovers after watering means the pot is too small; wilting that does not means the roots have rotted. A pot is a colder root zone in winter than the ground beside it, so anything left outside needs wrapping.