If you’re an urban gardener, container-grown edibles may be your best chance to raise food crops at home.
Growing food in containers requires less weeding and digging and is a great alternative for those who may be physically unable to tend in-ground plantings. Although they require less weeding, stooping, and digging, it is critical to consider that container plants need more regular attention than plants growing in the ground, as they rely solely on you for all of their needs.
Over the past several years, plant breeders and hybridizers have been busy creating vegetable, herb, and berry cultivars with dwarf or compact habits that are better suited for small garden plots, containers, and limited spaces. Read on for information on how to keep potted plants healthy and productive!
Soil & Container Type/Size
Always use quality potting soil, never garden soil, and plant in appropriate-sized containers (at least 12 inches deep) with adequate drainage.
- G&B Indoor/Outdoor Potting Soil is organic, full of nutrients, and has good texture for most edible selections.
- If re-using last year’s soil, “recharge” it with Worm-Gro worm castings or G&B Harvest Supreme, using up to 50% new soil to old.
- If planting extra-large containers, G&B Raised Bed & Potting Mix is a good filler, but should be mixed with G&B Harvest Supreme to boost nutrient levels and add beneficial microorganisms.
Watering
When it is warm and sunny, most containers will need one to two daily waterings. Test moisture levels by feeling the weight of the container or by putting a finger into the soil up to the first joint—water when container feels light, or soil feels dry beyond the top layer. It can be a challenge to learn how much and how often to water your plants so they get enough, but not too much water. Be sure to water your containers until the water comes out of the holes in the bottom of the pot. If you use a saucer to catch runoff, make sure plants are not constantly sitting in water.
Newly planted containers may need to be watered lightly, but more frequently until the plant roots extend into the surrounding soil. Often, newly planted containers benefit from some form of shade or protection from extreme sun and/or wind.
Cover potting soil surface with mulch to reduce evaporation between waterings. Mulching container plantings can be done with various materials including wood chips, straw, compost, leaf-mold (shredded, partially decomposed leaves), rocks, pebbles, or even recycled wine corks!
Some crops suffer from developmental or flavor changes when not watered properly. For example, lettuces and other greens may become bitter if allowed to dry out too frequently during growth. Tomatoes grown in containers are often prone to blossom-end rot if not watered consistently and provided with enough calcium (lime and bone meal) to form fruit.
Fertilizer
Most edible plant selections require supplemental nutrition to be as productive as possible. Without adequate fertilizer, plants can become vulnerable to the stresses of insects or diseases and often deliver lower than usual harvest yields. Slow-release, organic fertilizer is best added at planting time and reapplied monthly. We suggest G&B Tomato, Vegetable & Herb Fertilizer or G&B Citrus & Fruit Tree Fertilizer.
In addition to the slow-release granular fertilizer, plants can be given a liquid feeding that rapidly provides water-soluble nutrients when needed. Liquid fertilizing may be most necessary when plants are growing quickly and/or being watered frequently, but it can generally be applied about every two to three weeks. Depending on the specific crop and plant’s growth stage, we suggest fertilizing with G&B All Purpose, G&B High Bloome, or G&B High Growth liquid organic plant food.
Exposure
Most edible plant selections require at least six hours of sunlight per day to reach their full potential; you can grow shade-tolerant edibles such as leafy greens in areas with less than six hours of sun.
Protect container plantings from weather extremes like intense temperatures or high winds with temporary shade cloth or other screening materials. If growing during winter months, be sure to keep watch on extreme low temperatures. Always water container plantings thoroughly before a predicted freeze and consider moving potted plants to a protected area like a carport, shed, or space against the house and under the eaves. If unable to move a container, wrap the container with insulating materials such as old blankets or bubble wrap to keep the root ball from freezing.
Crops for Containers
Specially developed edible plant varieties for container growing are compact, dwarf, or slightly smaller, overall. The list of vegetables that can be grown in containers is long and includes bush beans, carrots, beets, chard, cucumbers on trellises, eggplant, kale, kohlrabi, leeks, lettuce, pak choi, peppers, radish, scallions, spinach, certain squashes, and certain tomato varieties (especially cherry types and determinate selections). Choose crops that are reliable, heavy producers such as parsley, kale, lettuce, cherry tomatoes, etc.
Interplant containers with a mix of tall and short crops—in a large container, consider planting a root crop such as a carrot or beet, a filler crop such as lettuce or a leafy green, and a trellised crop in the center such as cucumbers or peas.
Some New Varieties to Look For
- Tasty Patio Black and Tasty Patio Yellow Zucchini
- Spacemaster Cucumber
- Little Leaf Pickling Cucumber
- Tom Thumb Pea
- Little Gem lettuce
- Little Bells or Mini Bells Sweet Pepper
- Little Fingers or Parmex Carrots
Don’t even get me started on the list of herbs, berries, and fruit trees that are great for containers—just know that figs, blueberries, strawberries, raspberries, and fresh gourmet herbs await you!
More Edibles for Containers
Snap Beans
- Container: 5-gallon, window box
- Varieties: Bush ‘Blue Lake’, Bush ‘Romano’, ‘Compass’, ‘Cupidon’
Broccoli
- Container: 1 plant/5-gallon pot, 3 plants/15-gallon tub
- Varieties: ‘DeCicco’, ‘Green Comet’
Carrots
- Container: 5-gallon or window box at least 12 inches deep; sow seed 3″ apart
- Varieties: ‘Danvers Half Long’, ‘Little Fingers’, ‘Parmex’, ‘Oxheart’, ‘Round Romeo’
Cucumbers
- Container: 1 plant/5-gallon pot
- Varieties: ‘Little Leaf Pickling’, ‘Patio Snacker’, ‘Mini Munch’, ‘Persian Baby’, ‘Spacemaster’
Eggplant
- Container: 5-gallon pot
- Varieties: ‘Black Beauty’, ‘Ichiban’, ‘Slim Jim’, ‘Ophelia’, ‘Patio Baby’
Lettuce
- Container: 5-gallon, window box
- Varieties: ‘Ruby’, ‘Salad Bowl’, ‘Little Gem’, ‘Jade Gem’
Onions
- Container: 5-gallon, window box
- Varieties: any
Peppers
- Container: 1 plant/2-gallon pot, 5 plants/15-gallon tub
- Varieties: ‘Cayenne’, ‘Long Red’, ‘Sweet Banana’, ‘Wonder’, ‘Little Bells’, ‘Mini Bells’, ‘Pimento de Padrone’
Radishes
- Container: 5-gallon, window box
Varieties: ‘Cherry Belle’, ‘Icicle’
Squash/Zucchini
- Container: 1 plant/5-gallon pot, 3 plants/15-gallon tub
- Varieties: ‘Reno’ compact Acorn squash, ‘Butterbush’ compact butternut squash, ‘Bush Baby’, ‘Tasty Patio Black’ or ‘Tasty Patio Yellow’ zucchini
Tomatoes
- Container: 5-gallon if determinate, 15-20-gallon if indeterminate
- Varieties: Determinate cultivars include ‘Oregon Spring’, ‘Patio’, ‘Willamette’ and many more; Indeterminate cherry cultivars include ‘Sungold’, ‘Sunsugar’, ‘Sweet Million’, ‘Sweet 100’, ‘Snow White’, and ‘Chocolate Cherry’. Look for compact ‘Tumbling Tom’, ‘Cherry Falls’, ‘Pot n’ Patio’, and other new varieties introduced each year!