Carrots:
Carrots are a perfect vegetable to grow in a pot. Start with baby varieties like ‘Little Fingers', ‘Short 'n Sweet', or ‘Thumbelina'. If you water diligently, you can get a bumper harvest in pots as shallow as 6 to 8 inches deep. Longer varieties need deeper pots. After thinning, you should end up with 20 or so carrots per 12-inch pot.
Cole crops — broccoli, cabbage, cauliflower, and so on:
All the cole crops grow well in containers as long as your pots are big enough; try planting three or four plants in a half barrel.
Cucumbers:
You can't go wrong growing small cucumber types like ‘Bush Pickle' and ‘Salad Bush'. I've harvested cucumbers out of 12-inch-diameter hanging pots — planted with three seeds to a pot. Plants dangling over the edges of a hanging pot are something to behold. Plant large-growing varieties in bigger pots and slip a sturdy wire cylinder into the outside edge of the pot for the plants to climb on.
Eggplant:
An eggplant's purple foliage and compact habit are perfect for pots; any variety works as long the container is at least 5 gallons. Plant one eggplant per 5-gallon pot. If a plant gets floppy, push a small stake in the pot to support the plant.
Lettuce and other greens:
Lettuce and greens may be the ultimate container vegetables. The size of your pot doesn't really matter — just sprinkle some seeds in it, keep the soil moist, and then get out your salad bowl for a great harvest. You can harvest the whole plant or snip off just what you need. If you want a really pretty pot, plant some ‘Bright Lights' Swiss chard.
Melons:
Melons aren't ideal container subjects; they're wild and unruly. But through the magic of modern science, some dwarf varieties, like ‘Bush Sugar Baby' watermelon, grow well in containers. Plant one to two plants in a big pot (at least 5 gallons) and let the vines sprawl over the edges, supporting the fruit if necessary. And don't let up on water and fertilizer.
Onions:
Green onions — scallions or bunching onions if you prefer to call them that — grow well in containers. Just buy a bag of sets, plant them 2- to 3-inches deep, and you're in business. You can grow onions to full bulb size; just make sure that you use a big pot (preferably 5 gallons) and give them plenty of room to grow.
Peas:
Go with dwarf pea varieties like ‘Green Arrow' and ‘Maestro', English peas, ‘Sugar Bon' snap pea, or ‘Dwarf Grey Sugar' snow pea. Any variety larger than that needs a trellis. Planting six plants in a 12-inch pot should be fine.
Peppers:
You can grow any pepper variety in a pot, but the bigger the pot the better. I like to grow small-fruited varieties like ‘Serrano' and ‘Black Pearl' peppers; they produce so much colorful fruit that their containers become showpieces. A 5-gallon pot should hold one to two plants.
Potatoes:
Potatoes are fun vegetables to grow in a container. Just place 8 to 10 inches of potting soil in a big pot (at least a 5-gallon size). Plant two to three potato eyes 2 to 3 inches from the bottom of the pot, and then water them in. After the plants start to grow, cover the stems with more soil (leaving the very top exposed) until the pot is full. In a couple of months, you can harvest a pot full of spuds. Start harvesting earlier for new potatoes, later for larger ones. (For more on growing potatoes in small spaces using towers, see Chapter 6.)
Radishes:
Growing radishes is quick and easy even in the smallest container. Scatter some seeds in the top of a pot, keep the soil moist, and you'll have radishes in less than a month.