Vegetable gardens: Containers can add space, height and color
Containers are useful for adding height, color and growing space in the vegetable garden.
It is better to use fewer larger pots or planters than many small ones, which will look fussy and are harder on plants. Large containers retain soil moisture better and allow roots to become long and widespread.
Containers must drain for plants to survive, so make sure they have drainage holes, and don't place them on saucers. You can reduce the volume of soil if needed by placing bricks or large stones at the bottom of the pot and then lining it with filter fabric before adding soil and plants. Leave an inch or two between the soil line and the rim for easy watering.
Herbs like free-draining conditions and make ideal container plants. Lavender, rosemary, oregano, thyme, sage and basil are attractive and useful plants for containers. Fast-sprouting greens, such as mesclun mixes, loose-leaf lettuces, mustard greens and arugula, make for great spring and fall potted gardens. Add pansies or violas, both edible, to enliven the show.
Terra cotta and other freeze-damaged containers will have to be emptied and stored in a dry area for the winter.
You can grow some fruit trees in big pots of 20 inches or more, but the containers will need to be frost-proof if they are kept outdoors year-round. In sheltered gardens, container-grown sweet bay, fig, rosemary and dwarf pomegranate may survive Washington winters, especially if the pot is sunk into a garden bed in winter. Citrus trees and tender passion vines should be brought into a cool, bright room from October to April.