How to Plant a Container Garden

While some bamboo will grow well in containers, not all types are suited. Clumping types work the best, but be aware that any bamboo grown in containers won’t grow as thick or tall as it would grow in the ground. To give the plant room to grow, use the largest planter that is practical — at least 20 inches by 20 inches. Low, stable planters work best. Since bamboo is an invasive plant, look for a material the roots can’t easily get through. Metal works well, but it can transfer heat and cold easily, so you’ll need to have some sort of insulating material. A wood planter will insulate better than metal, but you’ll need to line it with plastic to help contain the roots. Whatever type of planter you choose for bamboo, plan to divide the bamboo every two to five years to prevent the root system from growing so large it cracks the container.

A cactus planter should have a diameter an inch larger than the base of the cactus. Shallow planters work well since cactus roots don’t grow very deep, but the planter should weigh enough to support a top-heavy cactus that is holding water. Clay pots, for example, are stable containers for a cactus, and unglazed clay pots will breathe, allowing the soil to dry faster. You shouldn’t need to repot a cactus often since they grow slowly.

Outdoor containers can make good homes for smaller types of trees. A planter for a tree should be large enough to allow the roots to grow out and down, but it shouldn’t be so large that it overpowers the look of the tree. It should be deep enough to hold about 2 or 3 feet of soil. Large planters also help keep the soil temperature more constant. Heavier planters are good choices because the wind won’t blow them over easily. If you decide to use a more lightweight planter, add a layer of stones to make it more stable. To see some ideas for planter trees, read Grow a Japanese Maple in a Pot and Dwarf Fruit Trees.

Selecting a pot for a bonsai tree can be something of an art, but there are some basic principles that can help you get started. In addition to choosing a container large enough to allow root growth, to find the right bonsai pot you also need to fit the container to the size and shape of the tree. The shape of the pot can reflect the shape of the tree — for example, a rectangular pot fits a tree that grows straight while an oval pot complements a curved tree. If you want an oblong pot, look for a length about 2/3 the height of the tree. Circular or square pots should have a diameter or length about 1/3 of the tree height. For trees that are wider than they are tall, base the sizing on the width of the branches. Shallow bonsai planters work for trees with narrow trunks, while a tree with a thicker trunk needs a deeper planter. The planter color should also complement the tree. You can choose a color that is present in the foliage or the flowers of the tree or pick a color that suggests the tree’s native setting.

Planters for orchids typically offer more drainage than a typical planter. In addition to having more and larger drain holes, an orchid planter may also have drainage holes running down the sides. However, standard planters with multiple drainage holes can be suitable for orchids as well. Many orchids have roots that spread outward rather than down, so they do better in shallow pots. If your orchid has deep roots, look for a taller planter. Keep in mind that pots with a wide base will be more stable for orchids that are top-heavy. There are a few considerations for container materials. While plastic pots do a good job of holding in moisture, they aren’t as stable as pots made of heavier material. You may need to steady them to keep the orchid from tipping over. Terra cotta and clay pots are heavier, making them more stable, but since the material is porous, the soil will dry out more quickly than with other materials, so make sure to keep the orchid properly watered.

Sunflower varieties that grow to a maximum height of 4 feet or less are suitable for containers. Those that reach the 4-foot mark need a good-sized, stable container — look for a capacity of at least 5 gallons. Lower-growing sunflowers can work in a container with a 12-inch diameter.

Herbs are favorites for growing in containers, whether indoors or out. While there are some varieties of herbs that do well in small pots, container herbs perform best when planted in pots that accommodate their full, mature size. Most need a pot from 6 to 10 inches in diameter. If you want to grow several herbs together, look for larger containers. You can purchase gardening kits that include the seeds and containers you need to start your own herb garden. Hydroponic or hydrogardening systems let you begin growing herbs indoors on a countertop with little or no soil. To learn more about starting your own container herb garden, see Grow Herbs in Containers.

Another edible, the onion, is also a good candidate for growing in containers. A gallon container with about 6 inches of soil is sufficient for starting a small group of onions or for onions to harvest as scallions or green onions. If you plan to grow onions to full size, you’ll need a container with at least a 5-gallon capacity that allows 3 to 4 inches of spacing between the plants and holds at least 10 inches of soil.

Succulents typically don’t have roots that grow very deep, so they usually don’t need deep containers. In addition to growing in traditional planters, succulents work in repurposed household items such as pots and pitchers. While very small containers can be a home for some succulents — such as a hens and chicks planter made from a teacup — containers that are too small (or too big) can prevent the plant from growing larger. In general, look for planters that will allow about a 1/2-inch space around a plant. If you’re placing several plants in a single container, you have a couple of options. A planter large enough to allow up to 1 inch of space between the plants encourages more growth. A planter that groups the plants closely together restricts growth but will immediately give your display a full, finished look. Pay attention to drainage. If the planter doesn’t allow drainage and you can’t drill a drain hole, be very careful not to overwater. For step-by-step instructions on planting a succulent container, see Plant a Succulent Bowl, and take a look at Succulent Planting Ideas to get some inspiration for creatively displaying these versatile plants.

Watch our Garden Basics video: How Do I Pick The Right Container?