Vegetables in Pots Are a Moveable Feast

When the vegetable garden’s beds, as outlined on the coming season’s planting plan, are all spoken for, and you wish there was just a little more space for a pepper plant or two, or a small patch of that new lettuce variety, think pots.  Vegetables in pots are a moveable feast.  The pot that this year grows lettuce in a shady corner of the perennial bed was used last summer to grow basil on the sunny porch steps.

Eggplant "Pot Black" (courtesy National Gardening Bureau)

Eggplant “Pot Black” (courtesy National Gardening Bureau)

Potted veggies are a feast for the eyes as well as the table.  We are not fond of eggplant’s texture or flavor, but in 2012 we grew a pot of the variety ‘Hansel” for its bright purple miniature fruits and lovely lavender flowers, both summer long features of this slender “little finger” eggplant.

Recommended Container Sizes for Vegetables

Almost any container will work, provided it has drainage holes in the bottom and suitable capacity.  Use the following table to determine the minimum size container needed for various vegetables.  For direct sown crops, sow seeds and thin seedlings according to packet directions.

Vegetable          Minimum Container Size         Number of Plants

Beans               5-gallon pot/window box         direct sow
Beets                5-gallon pot/window box         direct sow
Broccoli             5-gallon pot                             1 plant
Carrots              5-gallon pot/window box         direct sow
Cucumber         2-gallon                                   1 plant
Eggplant            5 gallon                                   1 plant
Green Onions    1-gallon                                   3-5 plants
Leaf Lettuce      5-gallon pot/window box         direct sow
Parsley              1 gallon                                    3 plants
Peppers            5 gallon                                   1-2 plants
Radish               5-gallon pot/window box         direct sow
Spinach             5-gallon pot/window box         direct sow
Squash              5 gallon                                   1 plant
Tomato              5 gallon                                   1 plant

Growing Medium

There was a time when container gardeners had to make their own growing media, mixing horticultural grade vermiculite, peat moss, perlite, and various mineral nutrients to produce a soilless mixture that would provide physical support for the plant yet drain well (garden soil drains poorly in containers).  The only other options were packaged soil mixes that were generally too tight, held too much water, and thus drowned plant roots.  Thank goodness those days are over!

These days there are some excellent soilless media for container vegetable production.  I use either ProMix or one of the Fafard mixes, adding composted cow manure or worm compost as a nutrient source (one part compost or castings for every four parts soilless mix) and wetting the mixture thoroughly before seeding or transplanting.

Fertilizing

I like to give all of my containerized veggies a shot of liquid fish emulsion once a month during the growing season, beginning a week or so after potting.  My thinking is that the frequent watering necessary for container production rapidly leaches nitrogen out of the pot and it needs to be regularly replaced.  I use half the recommended amount of the fish emulsion concentrate unless the plants tell me there is a definite nitrogen deficiency (yellowing foliage or no new growth) – too much nitrogen can delay flowering and fruiting.

Watering

Most importantly, avoid wetting the foliage of plants when watering since moisture on the leaves encourages plant diseases.  When to water will depend on the container size, plant size, and weather conditions, so you should check each pot every day.  Use your index finger to see if the soil is dry about an inch below the surface; if so, water the pot slowly, letting the water seep into the soil, until you see some water emerging from the drainage holes at the bottom of the pot.  This will ensure thorough watering.

I put our pots on large rocks or other surfaces that will allow excellent drainage of excess water.  The drainage holes of pots placed directly on the ground can become plugged with soil or roots that grow out of the container and into the surrounding soil.  Elevated pots are also less likely to attract slugs which like to spend the day beneath objects resting on the ground.

Mulches can be placed on the surface of the container’s soil mix to reduce water loss.  Keep in mind, however, that you may be providing another hiding spot for slugs.

Recommended Varieties

Vegetable varieties that are recommended for growing in containers typically have more compact growth habits.  For example, compact or bush type cucumbers, such as the variety “Little Leaf”, grown in a pot with a small trellis, will take up one-third the garden space as the vining types.  Similarly, the zucchini variety “Raven”, growing only 2 feet high and 3 feet wide, is ideal for growing in a 5-gallon pot.  Almost all varieties of lettuce and other leafy vegetables can be grown in containers.  The following table recommends several varieties of popular garden crops for growing in containers.

Plant Type                                                    Varieties

Bush Beans                  Provider, Strike, Tavera Haricot Vert, Bush Blue Lake, E-Z Pick
Beets                            Bull’s Blood, Detroit Dark Red, Red Ace, Early Wonder Tall Top,

Sprouting Broccoli        Santee, Hon Tsai Tai

Broccoli Raab               Spring Raab

Carrots                         Red Cored Chantenay, Yaya, Danvers 126, Necoras, Scarlet                                        Nantes, Dragon,Yellowstone, Negovia, Napoli, Jeannette, Miami,                                        Thumbelina, Minicor, Parmex

Corn                             Tom Thumb

Cucumbers                   Picolino, Little Leaf, Bush Champion

Eggplant                       Fairy Tale No. 226,  Hansel, Gretel, Ophelia, Falcon,                                                       Black Beauty, Pot Black, Ping Tung Long, Diamond

Leeks                           Alto, Bandit, King Richard, Tadorna

Sweet Pepper              King of the North, Ace

Summer Squash          Eight Ball Zucchini, Raven Zucchini, Geode Zucchini
Midnight Lightning Zucchini, Success PM Yellow Straightneck

Tomatoes                     Cherry Falls, Roma, Mountain Princess, Rutgers, Medford,                                          Sunkist, Gold Nugget, Bellstar, Green Tiger, Pink Tiger,                                                      Patio, Sprite, Husky Red, Husky Gold, Husky Pink

Tomato "Cherry Falls" (Courtesy National Garden Bureau)

Tomato “Cherry Falls” (Courtesy National Garden Bureau)

Container gardening is a rapidly growing avocation.  For me, growing a vegetable in a pot creates a moveable feast for both taste buds and eyes, a chance to try a new variety, a spot of color in the summer perennial bed.  For many urban gardeners, containers are the only gardening option.  Pots filled with vegetables, as well as flowering plants, are a common site on the balconies and patios of apartment dwellers.  For parents and teachers, growing veggies in containers is a great way to introduce children to the joys of gardening.

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About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)