Amid the coronavirus pandemic, many people are concerned about food security. Under normal circumstances, the Clatsop County Master Gardeners Association would be partnering with host agencies to offer the Seed to Supper program to increase food security.
As a substitute for in-person programming, we’re offering a series of posts on starting a vegetable garden. This science-based information comes from the Seed to Supper program, developed by the Oregon Food Bank. During these difficult times, the Oregon Food Bank welcomes your donations.
Want to grow your own vegetables but don’t have the space? Consider containers! As with in-ground gardening, a wide variety of plants can be grown in containers. Plants grown in containers have a similar growing season to in-ground plants, and they require similar amounts of sunlight.
But there are also some significant differences. For your container plants to be healthy and productive, you need to pay attention to the 3 R’s:
Right preparation: When you garden in containers, you’re creating a closed environment for your plants, so your containers need to be appropriately sized for what you’re growing. Plants with big root systems, like tomatoes, need big containers. All sorts of containers can be used—bushel baskets, gallon cans, well-cleaned plastic jugs with the tops cut off—but make sure that your containers have adequate drainage, drilling holes in the bottom as necessary. Seed packets and catalogs can help you determine what size container each plant needs to thrive. You also need to give your container plants the right kind of soil.
Because soil composition and drainage are critical in these closed environments, you must use potting soil, not soil from the ground or bagged top soil. Because you’ll need to buy potting soil, container gardening can be more expensive than in-ground gardening.
Pick a site where your container plants will get plenty of sun. Flowering vegetables, like tomatoes and beans, need at least 6 hours of sunlight per day. Plants with edible leaves, like lettuce and kale, need at least 4 hours of daily sunlight. Plants with edible roots, such as carrots and beets, need at least 3 hours of sunlight each day.
Right plant selection: Not all plants thrive in containers. Those that do thrive include cherry tomatoes, pole beans, peas, arugula, lettuce, gourmet salad greens, strawberries, kale, spinach, and herbs. As you consider seeds and starts, choose varieties that do well in containers. Look for dwarf, miniature, and container varieties in online seed catalog such as this one from Territorial Seeds.
Right care: Due to smaller volume, soil in containers dries out more quickly than soil in the ground, so you’ll need to water more frequently. For the same reason, container plants also require more fertilizer. If using soluble fertilizer that can be mixed in water, fertilize every three to four days with a solution that’s half the strength of the recommended mixing ratio. If you use dry fertilizer, fertilize every three weeks. Follow these same principles if fertilizing with organic materials such as compost and blood meal.
You’ll also need to water regularly, as the soil in containers dries out quickly. On sunny days, you may need to water daily. But don't let the soil become soggy or have water standing on top of it. Many plants don’t like “wet feet.” Water when the soil feels dry and until it runs out the drain holes.
Don’t put pebbles or marbles into the bottom of your containers; that will cause shallow roots. Instead, elevate your pots on bricks or boards so water can freely drain from the drainage holes.
After you harvest your spring and early summer crops, you can replant your containers with late summer and fall vegetables, just as you would with an in-ground garden.
Next up: Location, Location, Location