Despite the warm weather we’ve been enjoying this summer, the temperatures will soon drop, and fall will be here before you know it — and that means it’s time to begin planning the fall garden. Even if you’re short on space, many of your favorite vegetables can be grown in easy-to-assemble container gardens.
Vegetables can be organized into two categories — cool season and warm season. This simply means that some plants thrive in the cooler temperatures of spring and fall and can handle a light frost, while others prefer the warmth of summer. With the cool-season roster including: several lettuce and spinach varieties; cabbage; greens; broccoli; radishes; peas; carrots; beets; parsnips; and more, you’ll find yourself with a bumper crop of delicious vegetables right on your own patio! Some varieties of vegetables are quite handsome and are considered ornamental — Swiss chard, kale and red cabbage to name a few. Just follow a few important guidelines, and you’ll find how easy and rewarding container vegetable gardens can be.
Pick Your Pots
While I’m a big fan of terracotta pots, containers made from any material — wood, plastic, metal — are suitable for vegetable gardening. But one thing to keep in mind is the weight of the container after it is planted. Lightweight containers are ideal, but if you prefer a style that’s particularly heavy, place them on wheeled plant stands, or if you’re handy, install casters on the bottom of your pots. When it comes to size, I like containers that are about 20 inches in diameter, which allows me to grow more than one plant per pot. As far as depth, 18 inches is sufficient for to support the root system of most mature plants. It’s also very important that your containers have adequate drainage. Galvanized metal tubs are especially popular choices for vegetable gardens, but you’ll have to make your own drainage holes. If you decide to use wood containers, be sure the material has not been treated with creosote or pentachlorophenol. These chemicals can be harmful to both plants and people. You also don't want to use a container that has been used to hold toxic chemicals. Old or new, a good rule of thumb is to thoroughly rinse out containers prior to planting.
Select Your Soil
When it comes to soil for containers, don't fall into the trap of thinking you can just go into the backyard and dig up a little dirt — that soil is generally heavy and doesn't drain well. Instead, I prefer to use pre-blended mixes in bags. These are easier to work with, and the soil has been sterilized, so there's no problem with weed seeds. These blends are also designed to be lighter. The coarse organic material in perlite and vermiculite creates air spaces, making it easier for roots to develop, while peat moss and other forms of humus help retain moisture.
Planting & Care
For fall container gardens, most vegetables are better started from transplants purchased at a local garden center. Biodegradable peat pots, like those from Bonnie Plants, make planning a container garden much easier. Not only do the labels offer up specific information, such as spacing and care, but a variety of peat pot sizes allow for creative container designs that are a cinch to organize.
When determining your planting date and selecting crops for your vegetable garden, you need to know the number of days it will take for a plant to mature and the first frost date of the season. In my zone 7 garden, I start planting as soon as I sense that the heat is about to break, typically at the end of August to the middle of September. To determine when to plant on a plant-by-plant basis, it's best to come up with an imaginary harvest date a few weeks before the first frost date frost and back up from there based on the number of days it takes for a plant to mature.
In addition to requiring at least six hours of sun each day, container gardens need to be watered more often than a regular garden. When the top half-inch of soil is dry, it is time to water again; alternately, when the first plant in a container dries out, then it’s time to water everything.
But because frequent watering washes out nutrients, I like to fertilize my containers every five to 10 days with a liquid fertilizer. As with any chemical, it is important to follow the directions on the back of the package. You don't want to overdo it. Plants in containers are especially susceptible to fertilizer burn, because they do not have a large volume of soil to absorb excess fertilizer.
So often I hear homeowners say they don’t have the time or space to garden. Well, even though the conventional gardening season has now passed, try growing some cool-weather fall vegetables in containers. They are both beautiful and delicious.
