Adding a spray of color or the scent of fresh, growing vegetables to the living areas in your home is simple if you have the right materials. Although larger pots can take up more space, your plants need room to grow just like children need room to run and play. There is no one-size-fits-all-solution for plant pots, but in most cases you can use the full-grown size of your plant as a guide.
Annual and perennial flowers usually have less-stringent requirements than garden vegetables. Most annual vines and flowers or herbs less than 12 inches tall can thrive in a plant pot that is larger than 4 inches wide and deep. Annuals that grow to more than 12 inches need a larger pot that measures at least 8 inches tall and wide. Perennial plants need a bigger pot since they have to survive there for years. It is usually better to plant your perennials in a pot that is 8 inches deep and wide or larger.
Tall plant pots provide a deeper soil for indoor trees or large garden plants with extensive root systems. Large garden plants such as bell peppers (Capsicum spp.) or tomatoes (Solanum lycopersicum) grow best when they are planted in a 5-gallon container that is 12 inches deep with a diameter of roughly 11 inches.
Depth and Volume
Deeper plant pots hold more soil and are ideal for plants that need lots of moisture to grow. Most vegetables need at least 8 inches of soil in a container that is at least 8 inches in diameter to produce a healthy crop. Large plants such as summer squash (Cucurbita pepo) have shallow spreading roots that perform best in a wide container that is at least 8 inches deep by 36 inches wide and long. Smaller herbs and flowers can grow in pots with a 4- to 6-inch diameter.
Small container trees provide a luscious source of green in your home, but they can be a potential mess or a serious hazard if the pot is unstable. The best type of container to grow your large potted plants in has a square base or sides that run straight up and down with a flat bottom. Containers with sloped sides or a V-shape are inherently unstable and are more likely to tip over under the weight of child or pet trying to climb onto the planter. Using heavy containers made from glazed ceramics can add a decorative flourish to a practical consideration; heavy containers are more difficult to tip over.