How to Choose Pots for Your Container Garden
Plant containers come in myriad styles and types. When choosing pots for your container garden, consider the ultimate size of the plants you'll be growing, what the pot is made of, and some critical features you can't do without.
Garden containers: How big? What's it made of?
Gardeners can choose from clay pots, glazed or not; plastic pots, pretty or ugly; or wood pots, big or small. And that's just the tip of the iceberg. Here are some points to keep in mind when choosing a pot for growing vegetables:
Size: In most cases, pots that are bigger (in terms of width and volume) are better, especially for growing large plants like tomatoes. Lots of root space means that your vegetables are less likely to get cramped; they'll also be easier to water and fertilize.
With some vegetables, the depth of a container is as important — if not more important — as its width. You can grow quite a few carrots or radishes in a narrow container, but the container must be deep enough to accommodate the length of the plant's mature roots.
A half whiskey or wine barrel is a large, inexpensive container that can hold quite a few vegetables — ten heads of lettuce, ten bush bean plants, one or two small tomato plants, or four or five small cucumber varieties. You can purchase these containers at garden centers and nurseries.
Material: What a pot is made of can affect how often you have to water and how long the container lasts. Pots made of porous materials like clay dry out faster than those made of plastic or wood, so you must water the plants in them more frequently, especially in hot or windy climates. If you prefer wood containers, make sure they're made of rot-resistant materials like cedar or redwood; otherwise, they won't last very long.
Keep in mind that using preservative-treated wood containers isn't a good idea for growing vegetables or other edibles because the chemicals may leach into the soil and then into your plants.
Polypropylene bags are a recent innovation in vegetable gardening. Felt-like polypropylene is a breathable fabric that prevents overwatering and promotes good aeration. The bags come in various sizes and depths, and they fold flat for storage.
Must-have features for garden containers
No matter which style or type of pot you choose for your container garden, you can't ignore some key features:
Drainage: All the pots you use for growing vegetables should have drainage holes; fortunately, almost all do. But because a wooden half barrel often doesn't, you have to drill your own holes in the bottom of the container (eight to ten evenly spaced, 1-inch holes should be fine). If pots don't have drainage holes, the soil becomes a swampy mess, the roots drown, and the plants die. Bummer.
A saucer to place underneath your pot: A saucer collects water that runs out of the holes in the bottom of a pot and prevents the pot from staining whatever it's sitting on. You can find saucers made of the same or similar material as your pot or ones made of clear plastic. Plastic saucers are least likely to stain.
Just make sure you don't let water stand more than a day in the saucer; water rots roots and wooden pots.
Wheels for mobility: Most nurseries sell wheeled platforms that you place under large pots to move them easily. Otherwise, you have to lift the heavy pots or cart them around on a hand truck.
Self-watering containers for gardening
An especially useful type of pot is a self-watering container. This type of pot is made of rubberized plastic and has a false bottom and reservoir under the soil that can be filled with water. You pour water into a pipe at the top of the pot or through a hole in the side of the pot to fill the reservoir. A wick draws water up from the reservoir and into the dry soil so you don't have to water as frequently. These pots allow you to get away during the heat of summer and not worry whether your plants are getting watered.

Use self-watering containers to simplify watering.

Gardening Glossary
annuals
Plants that complete their entire life cycle within one growing season. The plant germinates from seed, grows and blooms, and then produces seed and dies.

Gardening Glossary
biennials
A plant that take two growing seasons to complete its life cycle. It germinates and grows leaves and stems in the first year; produces flowers and fruit (seed) in the second, and then dies.

Gardening Glossary
bolt
When a plant flowers or produces seed prematurely.

Gardening Glossary
cold frame
A wooden or concrete block box in which you can grow plants or hold dormant during the cold winter months.

Gardening Glossary
cole crops
A family of vegetables, including broccoli, cabbage, cauliflower, kale, and Brussels sprouts. They thrive in cooler weather.

Gardening Glossary
complete fertilizer
Any fertilizer that contains all three of the primary nutrients, N-P-K (nitrogen, phosphorus, potassium). Phrase is based on regulations governing the fertilizer industry. Does not mean that the fertilizer literally contains everything a plant needs to thrive.

Gardening Glossary
deadheading
The practice of pinching or cutting off spent flowers

Gardening Glossary
evaporative-pad humidifier
A humidifier in which fans blow across a moisture-laden pad that sits in a reservoir of water.

Gardening Glossary
harden off
The process of acclimating plants grown indoors gradually to the brighter light and cooler temperatures of the outside world.

Gardening Glossary
hardiness
The ability of a plant to survive is called its hardiness.

Gardening Glossary
humus
A stable end product of organic-matter decomposition that's believed to increase microbial activity in soil, improve soil structure, and enhance the root development of plants.

Gardening Glossary
Bacillus thuringiensis Bt
An effective bacteria that attacks only the larvae of caterpillar family insects. It is safe to other insects, animals, and humans.

Gardening Glossary
macronutrients
Mineral nutrients that plants need in the largest quantities: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Gardening Glossary
mulch
Organic or inorganic material placed over the surface of soil, usually directly over the root zone of growing plants. Used to conserve moisture, kill weed seedlings, modify soil temperature, provide attractive covering to garden beds.

Gardening Glossary
organic matter
Once-living stuff like compost, sawdust, animal manure, ground bark, grass clippings, and leaf mold (composted tree leaves). Used to enrich soil and improve soil texture.

Gardening Glossary
perennials
Any plant with a life cycle of three or more years. Herbaceous (non-woody) perennials include flowering plants and herbs, mainly. Woody perennials include trees and shrubs. Longevity depends on the plant and growing conditions.

Gardening Glossary
pH
The measure of soil's acidity. Soil with low pH means it's too acidic; soil with high pH means it's alkaline. Most plants grow best in soil with a pH value between 6.5 and 7.2. Neutral soils measure 7.

Gardening Glossary
photosynthesis
The process through which plants take nutrients from the air and from the water in the soil to produce sugars that fuels the plant's growth.

Gardening Glossary
primary nutrients
Nitrogen, phosphorous, and potassium are the three nutrients plants need in the largest quantities.

Gardening Glossary
root crops
Plants with edible underground roots such as onions, carrots, beets, potatoes, turnips. Most root crops are cold-weather crops.

Gardening Glossary
self-blanching
A type of cauliflower with leaves that naturally curl over the head and exclude light. Requires cool temperatures for leaves to curl effectively.

Gardening Glossary
sets
Small onion bulbs, about 1/2-inch wide, that were started from seed the previous year. Grow onion sets with the pointy end up.

Gardening Glossary
side-dressing
The act of adding a small amount of fertilizer around or "on the side" of plants after they're growing.

Gardening Glossary
succession planting
Planting small, 2-to-4-foot patches of plants every two weeks throughout the growing season so that you can harvest a crop over an extended period of time.

Gardening Glossary
thinning
The act of cutting the least robust seedlings in your garden to give the healthier plants more room to grow.

Gardening Glossary
vining crops
Crops that grow on vines, such as cucumbers, melons, pumpkins, and winter squash. They usually require support (staking, trellising, etc.) to keep them off the ground.