Container gardens are ideal for small spaces with little to no soil, including balconies, courtyards, decks and patios. They are also ideal for renters and individuals with limited mobility or limited time to care for a large landscape.
Types of Containers There are two types of containers: porous and non-porous. Pots that are porous look more natural but can deteriorate quickly if consistently exposed to moisture and freezing temperatures. During winter months, they should be brought inside to prevent cracking. Non-porous containers have a longer life span and may be stored outdoors in the winter; however, they are often made of potentially harmful materials such as plastic.
Types of Porous Containers • Clay pots • Wooden pots • Pots made of pressed fiber such as baskets
Types of Non-Porous Containers • Glazed pots • Plastic pots • Metal pots
The cheapest way to establish a container garden is to recycle materials that are no longer being used. Items that can be recycled into containers include bathtubs, buckets, baskets, crates, dresser drawers, wheelbarrows and sinks. Avoid tires and treated wood as they will leach chemicals into the soil. We also recommend avoiding metal as it will heat up in the summer, and your soil will dry out more quickly.
If your containers are made of non-porous materials, make sure they have drainage holes so that your soil does not become waterlogged. Two to four holes are recommended depending on the size of your pot. If a container has no holes, you may be able to drill some yourself.
Container Size Vegetable plants do not grow well if their roots are restricted, so it is important to make sure your containers are large enough for the plants you want to cultivate. Most herbs grow well in four-gallon (or eight to 12-inch diameter) pots. Basil, chives and cilantro can be grown in smaller, three-gallon pots. See page 20 for a list of recommended container sizes for popular vegetable plants.
Container Location Place your containers where they receive six to ten hours of full sun each day. Soil is heavy, so move your containers into position before filling them.
Container Soil Container soil needs to provide water, nutrients, oxygen and support for plants. Garden soil tends to compact in containers, reducing the amount of water and oxygen available to plants. To keep your container soil from compacting, you can buy potting mix or you can make your own. (Recipe is below)
Potting Mix: Most potting mixtures do not actually contain soil. Instead, they contain three basic ingredients: peat moss, which retains moisture, pine bark, which adds nutrients, and either perlite or vermiculite, which are lightweight volcanic rocks that are naturally filled with air and promote drainage. You can buy potting soil in any gardening store.
Do-It-Yourself Potting Soil: Garden soil can be used as a container medium but it needs to bemodified. Though it requires a little more work than buying potting mix, creating your own soilmixture can save you money because potting soil is relatively expensive. Garden soil mixtures canalso help your plants by adding beneficial microorganisms and nutrients to your containers. Makeyour own potting soil by adding one part garden soil that has been amended with compost, one part shredded coconut husks, called coconut coir (we do not recommend using peat moss as it is an unsustainable product), and one part perlite, vermiculite, coarse builders sand or shredded leavesDo not use fine beach sand or play sand.
When to change your Potting Soil: Because container soil sometimes harbors pathogens, many gardeners change the soil in their containers after each growing season. Other gardeners empty their containers after one or two growing seasons or if their plants are attacked by a disease or pests. How often you empty your containers is up to you.
Watering and Fertilizing Container Gardens Containers hold a limited amount of soil. They therefore store less water and need to be watered more frequently than garden beds. Every time you irrigate plants, water carries away some of the nutrients in the soil. Consequently, container gardens also require more frequent fertilizing. There are two-types of fertilizers: slow or timed-release fertilizers and water-soluble fertilizers. For environmental reasons, always use organic fertilizers, which you can find at most local nurseries.Slow-release fertilizers provide a steady supply of nutrients to plants over an extended period of time (usually months). They include compost as well as granular fertilizers, which you can buy at most gardening stores. One or both of these should be added to your soil before you plant. Water-soluble fertilizers release nutrients to plant rootsimmediately and for short periods of time. Depending on your plants’ needs and your soil, you may never use water-soluble fertilizers, or you may water with fertilizer every one to two weeks. If you use water-soluble fertilizers, follow product directions for concentrations and timing.Different plants need different amounts of water andnutrients. It is best to grow plants with similar needs in the same container. Below are some recommended combinations of herbs and edible flowers: