With container gardening, it's surprisingly easy to slip into unsustainable practices—here's how to keep it green.

Container gardening is ever-popular with city dwellers and those who do not have much space for in-ground growing. It is also popular with those starting out and growing their own food for the first time.

But even those who have a garden can still have containers to make the most of all their growing space.

However, some may ask themselves: Is container gardening really the most sustainable choice? Unfortunately, it can often be less eco-friendly and sustainable than we might wish.

These tips and ideas for a container garden should help you make the most ethical and eco-friendly choices for today and for the future in your garden.

Must-Haves for a Sustainable Container Garden

To grow your own food and flowers successfully at home in containers, you will need more than just the containers, something to fill them, and your plants or seeds.

For a container garden to be sustainable—literally able to endure and persist over time—we need to think about what is required to sustain any garden over the longer term.

Sustainable Water

The first thing we need to think about is where the water we use to water or irrigate our container garden will come from. Remember, container-grown plants will typically need to be watered more frequently than those growing in the ground.

The first must-have for a sustainable container garden, therefore, is a sustainable water supply. This usually means looking at how we can catch and store rainwater on our properties.

Typically, this involves making sure guttering is attached to downspouts on our homes, and directing rainwater to barrels or tanks.

Water might be manually taken from these sources to water a container garden, or, in some cases, directly irrigated from them. Rainwater might also be fed into an aquaponics growing system. But however it is directed, collecting rainwater on our properties is typically essential for all kinds of container gardeners.

Fertilization

Another important consideration is how we ensure fertility in our garden moving forwards. Central to that is a good composting system. Having one in place will make things a lot easier in this regard.

There are also other systems you might establish in order to obtain important materials for your container plants—such as a bokashi system, leaf mold creation, and creating your own liquid plant feeds, to give a few examples. But some form of compost is an absolute must.

When possible, it's best to be making fertilizers yourself with inputs from your home or garden, rather than buying commercial products. As in many other areas, striving for closed-loop systems in the garden is the greenest way to go.

Sustainable Container Ideas

When you have sustainability in mind, the true cost of items and materials you use is one more in a long list of factors to consider when choosing containers for a container garden.

Plastic is commonly used in many containers. But as Treehugger readers no doubt are already aware, this is a material that comes at a cost to people and our planet. Derived from fossil fuels—with a high carbon footprint, and creating a waste problem at the end of its useful life—purchasing new plastic is best avoided where possible.

Fortunately, there are more sustainable materials from which containers can be made—such as stoneware, clay, terracotta, wood, etc.

And we can also reuse and upcycle materials and items from our homes to grow our plants. Consider empty food containers, pots, pans, sinks, tubs, toilets, washing machine drums, old clothing, single boots, or shoes. The possibilities are nearly endless.

Quirky, sustainable container options are everywhere. Of course, making use of items as containers that would otherwise be thrown away also helps to combat our waste problem and keep those things in use for longer. Additionally, it saves the money we would have spent on buying containers for our gardens.

Sustainably Filling Containers

When it comes to filling containers, a major mistake from a sustainability standpoint is to fill them with a growing medium that contains peat. Peat comes from peat bogs—vital carbon sinks and biodiversity hotspots. Rather than digging it up for horticulture, we should be leaving it in the ground.

Rather than using peat, we should all be using alternative potting mixes—either ones we can purchase (ideally organic ones) or those we make at home on our own where this is possible.

Your own homemade compost can be an important ingredient in potting mixes for a container garden. Taking a DIY approach is usually the most eco-friendly and sustainable choice.

For most vegetables I grow, I find this mix works well:

• 1/3 loamy soil
• 1/3 homemade compost
• 1/3 leaf mold

With these tips and ideas, you can create or expand your growing space without falling into traps that leave a lot to be desired.