Choosing the right size, shape and style of containers is one of the first decisions you’ll have to make when it comes to starting a container garden. You’ll need to factor in things like the garden’s size, location, and the size and shape of the plants you want to cultivate.

There are many types of containers sold at your local garden or hydroponic supply store, giving modern growers more options than ever when it comes to selecting the right ones for the needs of their plants. There are some important things to consider when looking for a container, such as:

  • Can it be reused?
  • Can it be cleaned?
  • Is it safe to use chemicals to clean it?
  • Is it porous or non-porous?
  • Does it allow for good air circulation?
  • Does it allow for adequate drainage?

Leafy greens like lettuce, parsley and other shallow-root plants don’t need deep containers, while tomatoes, beets, onions, carrots and other deep-root veggies do. Taller-reaching plants like tomatoes, roses and crawling vines take up a lot of space, so knowing where to place your containers will help you design the most productive garden possible.

In a greenhouse, for example, using smaller trays or containers on raised beds ensures optimal use of space, with smaller plants against the walls, and offers storage and other options underneath. Placing larger containers in the center of the greenhouse gives the height space required by some plants.

Some containers, such as fabric containers, offer better airflow and drainage to the root base than others while others are scavenged buckets, coffee cans and other household items. There are even some pre-formed containers that fit together and can be vertically stacked, which are great for strawberries and other smaller plants. I look for containers that are fairly inexpensive, allow for optimal drainage and airflow, can be cleaned and reused, and are durable and available in many sizes.

The most common container sizes are 5 and 10 gal., which can hold fairly tall plants and accommodate huge root masses. Larger containers that hold more than 30 gal. can be put on wheeled platforms, like furniture dollies, so they are easy to move around. Ground-based containers containing 100 gal. or more of potting mix are often built partly into the ground. This is a popular way of growing large plants and trees. Finally, containers should always be a dark color so light doesn’t interfere with the root mass.

Things to Consider When Buying a Potting Mix

Once the style and size of your containers has been determined, it’s time to decide how you’ll fill them up. Simply putting some dirt in a pot with a seed, some water and sunlight won’t provide the results you are looking for. The potting mix you choose must fulfill the needs of what you are cultivating. Adding organic matter to your potting mix will provide the beneficial nutrients your garden needs. Keep in mind that some items like eggshells and coffee grounds need to be treated first before you can add them to your soil.

Adequately mixing your grow media is an important step. If you’re using a composting-style soil bin, you want to make sure you have removed the larger organic matter before mixing. Many gardeners I know use large plastic trays or kiddie swimming pools to mix their soil in. These pools are cheap, easy to find and can be used for many years, but you’ll need to keep it covered to keep windblown seeds and pests from getting into your soil.

There are many different recipes for mixing your soil, and starting off with a good base soil is essential. Most major brands offer potting mixes that are already mixed with everything you need. Read the labels carefully, and don’t be afraid to ask questions at the store. If you choose to make your own potting mix, you will have to amend it with all the nutrients your particular crops need to grow.

Knowing what your plants need is extremely important so you can tailor your mixes for better overall production. Tomatoes require more of a sandy substrate with higher alkaline levels than onions or carrots require, for example. Here are some useful and easy items to use to help fertilize your soil:

  • Crushed eggshells
  • Coffee grounds
  • Epsom salt
  • Crushed rock dust
  • Worm castings
  • Kelp
  • Bat guano
  • Composted garden waste

As mentioned earlier, drainage and airflow both play an important role in your soil. Adding perlite to the mix improves its airflow and allows for better drainage. It also makes it easier for plant roots to penetrate the grow media. Remember, the root mass is what holds a plant in an upright position, so you need to shoot for strong root masses in your containers.

Plan for Pest Control

One final step when planning your container garden is having a plan in place for pest control. Keeping pests out of your containers takes a multi-pronged approach. Treating your soil and water before any problems show up means you are one step closer to keeping containers clean and pest-free at all times. Putting a petroleum-jelly product on the upper edges of your containers will help keep the smaller crawling bugs at bay.

Adding ½ in. of clean playground sand to the top of the soil will prevent the creepy crawlers from emerging from your soil after they have hatched. If they can’t get out, they can’t lay more eggs, and will eventually die off. Fungus gnats, root aphids, thrips and other pests cause major problems in any garden they manage to invade, so take the time to stop them before they start.

When it comes to container gardening, using the right type of containers and the right kind of potting mix will lead to better root masses and a more productive garden.