How to Create a Container Garden

Wherever there is light, there is an opportunity to grow, so no matter where you live, you can have a garden! The difference is in the scale. Apartment dwellers might grow herbs and salad greens on a balcony, or flowers on window sills and ledges. Renters can pot up tomatoes and monstera; anyone can grow herbs on the kitchen bench. The benefits of growing far outweigh the cost and effort required to keep a plant alive. Here are our best tips on getting the most out of gardening in containers.

Choosing a container

The obvious choices here are pots and planter boxes, which you can find at hardware stores and garden centres everywhere, or look online for a huge range of options. If you plan to purchase a planting structure, check the quality of the build, the weight (once full of soil) and whether the container has a lining to prevent water and soil leakage and to provide a barrier between treated wood and the soil you’ll be growing in.

Purchased or crafted planter boxes can make a garden of any space.

Another option is to create your own planter box. The internet is teeming with instructional videos and blogs for building planters; take a look at this, this or this one.

Building from scratch is all very well, but upcycling is often easier! Nearly any container can house a plant. If it doesn't have drainage holes, these can be created using a drill or simply a nail and hammer. Buckets, tubs, baths, basins, teapots, and even plastic or polythene bags can be turned into planters.
Side note: If you're using anything made from plastic, ensure it is modern, BPA-free plastic.

From chic to repurposed, DIY or upcycled, most containers are suitable for planting; just add drainage and good potting mix.

Drainage

Drainage in container gardening is just as important as watering. Lack of adequate drainage can literally drown the plant and cause root rot. Drainage is more important with plastic containers than clay or terracotta pots because clay breathes while plastic does not allow evaporation to occur in the depths of the container. As mentioned above, if your container doesn’t already have holes, you can use a drill or hammer and nails to create holes in the commonly used pots and containers we've mentioned.

Start with a base of non-organic matter to allow space for water to drain and prevent the bottom of the container from getting compacted. Gravel, broken terracotta pots or even squashed aluminium cans will do the trick.
Tip: Rather than fill a large container with heavy soil, use your drainage base to build up the level to where it needs to be.

Berries thrive in containers and are simple to grow!

The growing medium

Add a good potting mix next. Don't use soil from your garden, because it will compact in the containers and won't drain water properly. It may also contain weeds and disease, negatively affecting your plant's new home. The potting mix should be lightweight, to enable good drainage and prevent root rot. This also allows nutrients to get to the roots easily. A good potting mix might include vermiculite, perlite and peat moss; you can even mix your own. It’s beneficial to add slow-release fertiliser and water-absorbing crystals to the soil. The crystals absorb water and turn into a gel, slowly releasing the water to quench the plant. Be sparing with the water-absorbing crystals; too much will clump together. One teaspoon of crystals can absorb four cups of water! Water in well with liquid fertiliser. Over time the slow-release fertiliser will break down and do its job of nourishing the plants. 

Add a thin layer of mulch such as bark or pea straw to keep moisture in. You can purchase many varieties of mulch or try making your own using dead leaves chopped up with the lawnmower! Compost or grass clippings can also act as mulch.

When planting, follow this 3-step watering rule: water the plant, water the hole, then water it in thoroughly once planted. Let excess water drain out before you put the container into place.

No matter the scale, you can successfully grow your own food in containers.

The right plants

Depending on the purpose, choose plants that prefer the same conditions to place together. Veggies and herbs are a good mix, but ferns and cacti are not. Here are some suggestions for a flourishing and useful container garden:

Pizza garden: tomatoes, basil, oregano

Add a trellis or stake and put the tomato in one end so it doesn’t shade the smaller plants. Use a dwarf/patio variety of tomatoes if your container is not large. Basil will grow bushy so place it in the centre. Oregano grows in a trailing manner, so place that near the edge and it will spill over attractively.

Salad garden: lettuce, tomatoes, basil, capsicum, rocket

Once again, stake your tomato and place it towards the back. Capsicum is the next tallest plant, then basil, then rocket and lettuce or mesclun mix.

Flower garden: sweet peas, potted colour, calendula, borage

Sweet peas (even the dwarf variety) require a stake or trellis. If picked frequently, sweet peas will continue to flower for weeks and even months! Potted colour can be a lot of fun to grow, pick off dead and dying flower heads to encourage new growth. These plants are usually annual and will die off at the end of the season. 

Companions: marigold, calendula, borage, basil

These plants help to ward away pests and improve the soil of other nearby plants.

Veggies: peas, courgettes, cucumbers, capsicum, chilli, lettuce and salad greens

These will all grow in pots and containers, giving you an abundance of fresh produce all summer. In fact, capsicum plants like the confines of a container!

Herb garden: basil, parsley, coriander, tarragon, thyme, mint

Keep your herb garden near the kitchen - or inside the house - to easily take advantage of their colour, flavour and health benefits at nearly any meal.

Fruit: strawberries, blackberries, blueberries

Berries love growing in containers and most will stay alive through winter to fruit again in the next growing season.

Watering

Many vegetable plants, such as tomatoes, need lots of water. However, you don't want to drown your plants. The goal is to keep the soil evenly moist but not soaking wet.

To figure out whether your plants need water, stick your finger down into the soil about an inch. If the soil feels dry, add water; if you're unsure, wait and check later in the day. At the height of summer, you'll probably need to water at least once or sometimes twice a day. This is often the most high-maintenance and critical aspect of vegetable container gardening. The best time to water is early morning before the sun gets too hot. Water on hot leaves can scald them: watering in the evening can encourage sooty mould and other fungal diseases.

Key tip: As the plants grow taller, water the soil, not the leaves of your plant.

Fertiliser

Check your local garden centre for advice on fertiliser - some plants, such as tomatoes are gross feeders and require more frequent fertilisation than others. Generally speaking, a good liquid fertiliser should be applied to your plants every fortnight for the best results. 

Hot eco tip: Does your household consume bananas? Don't throw away the peels once you've eaten them! Chop them up and soak them for a couple of days in a bucket of water, then use the water to fertilise your plants! Throw the remains into your compost to further make use of their soil-nourishing properties.

Want some more garden inspo? Check out this blog with tips on getting your garden and garage in shape for the coming months. Or get nature to do some work for you with these tips.

Back to articles