Low-carbon container growing
From choosing your container to picking your plants, there are lots of easy ways to make sure your potted garden is a sustainable haven
Although potted plants have a smaller role to play than plants in the ground, they still take carbon from the air. Indoors, they’ll also help create a more natural environment by absorbing pollutants and oxygenating the air. Manage them sustainably and you’ll maximise those benefits.
Sustainable ways to grow plants in pots
Part 1 - choosing your pots and plants
- Use second-hand containers: look in reclamation yards, vintage shops, and online auctions for zero-carbon pre-loved planters. Choose the biggest you can: With a few exceptions, the larger your pot, the more your plants can spread out their roots. Choose pots that have a diameter of at least 45cm (18in). Or build your own planter boxes from reclaimed wood.
- Grow plants that like container life: Plants that are happiest in containers are relatively slow growing, with naturally small root systems, such as dwarf (“patio”) fruit and veg, small shrubs like skimmias, and herbs.
- Use pot dishes: Catch and recycle water and by using containers with saucers or reservoirs wherever possible.
- Plant permanently: Permanent shrubs, trees, perennials, and grasses absorb carbon over the longest period and generally need less , water, and fertilizers than hungry, fast-growing .
Going peat-free is vital for sustainable gardening. However, the only truly low-carbon way to grow in containers is not to buy compost at all, but to make your potting mixes at home.
Mix your compost as needed. You don’t have to mix huge amounts at a time – use a loaded spade as the measure for a wheelbarrow load, or a trowel if all you want is a bucketful.
For potting on and containers:
4 parts loam
1 part garden compost, municipal green waste, or well-rotted manure
1 part leaf mould
1 part sharp sand
1 heaped trowel of seaweed meal per loaded wheelbarrow
This is a basic mix. Add more sand for alpines and herbs, and use composted bracken instead of garden compost for acid-loving plants like blueberries.
Part 2 - sustainable techniques
- Grow from seed: Raise your own annual flowers, bedding plants, or vegetables from seed, sown into pots of home-made compost.
- Don’t change all the compost: When replanting in spring, leave as much compost undisturbed as possible by digging out and replacing only the top 5cm (2in) of old compost.
- Use captured rainwater: Plants prefer rainwater, as it’s full of nitrogen and slightly acidic (unlike tapwater, which tends to be limy). You’ll avoid all the emissions involved in treating and transporting tapwater, too.
- Feed with home-made fertilisers: Artificial fertilisers are another source of greenhouse gas emissions (and tricky-to-recycle plastic bottles) so make your own.
- Grow a container fruit garden: Potted orchards of fruit trees and berries are the ultimate in sustainable container growing, majoring on permanently planted, carbon-rich woody trees.
"Mining peat for gardening releases a huge amount of carbon into the atmosphere. There are better and more climate-friendly choices for potting compost."
