Growing Vegetables and Flowers in Containers

Container gardening is ideal for small spaces, or can be used to emphasize plants seasonally. This article discusses appropriate plants, soil, and types of containers to use.
Growing Vegetables and Flowers in Containers - Articles

Updated: May 21, 2018

Growing Vegetables and Flowers in Containers

Photo credit: Mark Krotulski

If you have limited time or space, container gardening is an attractive alternative to growing plants in the ground. You can have a garden on your patio, balcony, deck, or porch by using pots, baskets, boxes, or barrels to contain your flowers and vegetables. There are numerous benefits: you can control the soil composition, move the pots around to take advantage of the weather, call attention to a unique plant, and change the entire look of your space. I have ample room to garden in the ground, but I add containers to make bold statements and highlight seasonal changes. They make pleasing additions to any outdoor area. Here are a few simple ingredients for success:

Select Suitable Containers

Containers may be made of plastic, terra cotta clay, metal, wood, fiberglass, or concrete. In addition, you may grow vegetables in buckets, milk jugs, ice cream containers, bushel baskets (lined with perforated plastic), barrels, dishpans, or trash cans. If your container is for flowers, it is important that it is pleasing to you. Choose a color to accentuate the flowers that you plant in it. All containers should be clean and non-toxic; they must have at least one drainage hole. The size will vary, but most plants need at least six to eight inches for adequate root growth. I find containers that hold at least two gallons of soil work best. Remember, that small pots dry out very quickly and tend to blow over in windy weather. Very large containers can be quite heavy, so consider using dollies or plant caddies (platforms with wheels.) Placing plastic saucers under your pots or using self-watering containers will prevent water stains on your concrete patio or wooden deck. When you elevate your planters slightly, you help the drainage holes work properly.

Choose the Right Growing Medium

Good growing mixes provide essential plant nutrients, hold adequate moisture, and allow excess water to drain. There are two types of growing media: those that contain soil and those that don’t. Never use soil straight from your garden by itself, as it may contain too much clay. Clay holds moisture when wet, blocking air from the roots. Also, be aware that garden soil may contain insects, weed seeds, or diseases. For vegetables, you may use a high quality packaged potting soil from the local garden center. Soilless mixes are usually too light for vegetables, so you could mix them with 25% soil. I make my own growing medium with one part peat moss, one part garden loam, and one part perlite.

Select the Best Vegetables

You can grow most annual vegetables in containers with the exception of sweet corn, because it needs numerous plants for adequate pollination. Also, vining crops like squash, pumpkins, and melons require more space. There are some new cultivars that are suitable for containers: bush-type squash, cucumbers, and melons grow as compact bushes rather than as sprawling vines. When choosing tomatoes, look for determinate cultivars that grow to a predetermined height. Indeterminate tomatoes grow too tall. Some examples of vegetables, size of containers, and spacing: Plants for one half-gallon container are beets planted two to three inches apart, Swiss chard or lettuce planted four to six inches apart. Plant one cherry tomato in a one-gallon container. For two-gallon containers plant bush beans two to three inches apart or bell peppers one plant per container. Plants for five-gallon containers are cabbage planted 12 to 18 inches apart or cucumbers spaced 14 to 18 inches apart. Plant one eggplant, one summer squash, or one tomato in a five-gallon container.

Create a Four-Season Flower Container

  • When choosing plants for flower containers consider the following: Are they growing robustly at the base? Are the leaves healthy with no spots or pests? Will the size of the plant, as stated on the tag, meet your needs? Do the growing requirements of the plant coincide with the location of the container—are you placing it in full sun, shade, or part sun/shade?
  • You may feature just one plant in each pot or consider the thrill, fill, spill concept: place one plant in the center to ‘thrill’ the eye and draw attention, ‘fill’ the planter with an accenting color, and pick one or two plants to ‘spill’ over the sides to soften the appearance. Many gardeners use the spike dracaena as the ‘thrill’ plant. I prefer red fountain grass, or you may try snapdragons, salvia, coleus, or dahlias. Suitable ‘fill’ plants are African daisies (Osteospermum sp.), million bells (Calibrachoa sp.), some zinnias, and geraniums. Examples of ‘spill’ plants are wave petunias, sweet potato vine, alyssum, and lobelia.
  • To create four season containers you can completely change some pots each season or just change a few plants. In spring, plant bulbs, pansies, dianthus, primulas, lobelias, and snapdragons. In summer, you may use tropical plants such as cannas, or try miniature sunflowers. I use zinnias and marigolds for my summer containers; this year I may try dahlias. In fall, you need oranges, deep golds, and rich reds. Mums are the obvious choice, but calendulas, ornamental kales, snapdragons, and pansies also work well. Try edibles like Swiss chard in your fall containers. In winter, fill your planters with boughs of evergreens and with red twig dogwood for a stunning display. Holly, daphne, boxwood, and small conifers give winter interest.
  • Don’t be afraid to add perennials to your containers.
  • Group your planters by varying their heights, standing some on bricks for example.
  • Place large, bold containers in the garden itself. Work them into a flower or shrub border for specimen or sculptural accents.

Photo credit: Chris Abel

Plant With Care

Cover the hole in the bottom of the planter with a rock or a piece of landscape fabric to prevent clogging with soil; add the media. Fill the container until it is half to three-quarters full. Set your transplants on the mix and add potting media to one-inch below the rim and press lightly. Sow seeds and plant transplants to the depth and spacing stated on the seed packet or tag. Put your container where it will receive the required amount of sunlight for the plants’ needs. Water thoroughly.

Take Care of Your Container Garden

  • Soil in containers can dry out very quickly, so check at least once a day and water as necessary. Do not allow the media to become completely dry. Apply water until it runs out of the hole at the bottom.
  • Fertilize with fish emulsion every couple of weeks at the dilution recommended on the bottle. If you purchased a soil mix with added fertilizer, then you won’t need to do this for eight to ten weeks.
  • Periodically check vegetables for insects and diseases.
  • Shelter your containers in severe weather, and protect from early fall frosts.
  • Keep your plants well groomed by removing spent flower heads.
  • Harvest vegetables when ripe so the plant will continue to set more fruit.

With just a pot of colorful zinnias or a barrel of red peppers you can brighten a dull area of your garden. By following these tips, you can grow almost anything in a container that is grown in the ground.

Authors

Pamela T. Hubbard