What you can do with a few pots, buckets, and bowls. Plus, Phase 3 of a beginner's garden.

Click here  for the third installment of Slate's guide to planting a beginner's garden. Click here and here for the first two installments.

A garden I admire a lot has no lawn, no trees. It's the sort of garden you might see in front of a whitewashed house in Greece or Sicily. Flowers spill out of a dozen of more containers—clay pots of different shapes, a couple of olive oil cans, a blue plastic bucket, a chipped ceramic bowl. The flower colors are mainly pink and red. There are bougainvillea, plenty of geraniums, maybe some basil, and a pot of coleus in the shade by the door.

The Mediterranean sun, of course, brings out the flowers. And the plants manage to thrive in the heat because they're watered regularly, probably by a woman dressed in black. The effect is both generous and thrifty; the flowers abundant, the containers humble.

Many Slate readers, to judge from the e-mails you've been sending, have only a balcony or a small patio. Rest assured: You can be a true gardener with a half-dozen or dozen containers, or just two pots on your front steps. Container gardening can be a great relief from having to deal with actual dirt and the rocks and weeds that come with it.

A cautionary note, though. A plant in a pot is a lot more dependent on you than it would be if it were in the ground and could spread out to look for water and nutrients. Think of it as a pet—a quiet and thirsty one. How often should you give it water? You need to check every day, no kidding. Pots in the sun need water almost daily. Small pots dry out faster than large ones. Woodland plants, like ferns and impatiens, want to stay moist.

The aspiring container gardener may find him- or herself stopped at the outset by a first piece of advice, which is crucial but seems bizarre and contradictory. Garden books, plant tags, and nursery staff all tell you to give your plants "moist, well drained soil." Or in fancier words, soil that is "fast draining yet water-retentive."

If your bathtub is well drained, all the water goes down the drain. After a minute or two your tub is not moist. Indeed, water retention would be a bad thing. For the soil in your pots, the water has to flow through, not puddle. That conscientious Greek or Sicilian woman dressed in black (or her plant-appreciating male equivalent) has drilled holes in the bottom of her turquoise bucket, her olive oil cans, her ceramic bowl, and every one of her clay pots.

Here's the reason. Roots need air as much as they need water. If the soil is saturated, all the tiny air spaces become waterlogged and sludgelike. Unless you're growing a water-adapter like a lotus or a mangrove tree or rice on your balcony, the plants in your care will rot.

But the soil also has to be able to hold moisture without getting saturated. This can work if it has plenty of organic content—tiny bits of peat moss or decaying leaves or bark that act like sponges, holding the water where the roots can get at it. In addition to these water-holding elements, commercial potting mixtures generally have some mineral material—usually perlite or pumice—that keeps the soil fluffy and airy. The mixtures are soilless, so they're really potting stuff rather than potting soil.

You could easily end up paying as much for a bag or two of potting stuff as for your plants. But it's worth it. Digging up regular old soil from your garden is a mistake. Garden soil is too dense to use in a pot. Some books say garden soil comes bearing diseases or critters, but the main drawback is that it's heavy and airless.