Corner box planters can be used indoors and outdoors to fill an under-utilised space with foliage and bright colours. They can sit beautifully on a shelf or fit neatly into the corner of a balcony or patio. Some outdoor planter boxes even incorporate a shelf in their design.
If you’re feeling adventurous, you could try a pond corner box, bringing some wildlife and aquatic plants to your garden. Read on to discover the best design to suit your space and how to make it.
There are a few things to consider before you start:
How much weight will your corner planter box have to take?
If it is mounted off the ground, consider the material of the planter box. If it’s made from wood, it’s likely to be heavy, especially when filled with soil. When you water it, the soil becomes heavier again so you may want to choose a plastic or wicker planter box.
If your planter is on the ground, you don’t need to worry about the weight. You can buy corner planters made from wood, plastic and ceramic to suit all budgets and spaces. However, if you decide to have a pond corner box, think carefully about the weight of the box and the water when it is filled up. See more below.
How much light will your planter get in both summer and winter? Does the sun ever reach this corner? If not, you will need to ensure that you provide artificial lighting or that you choose shade-loving plants.
Light can be provided by artificial bulbs but my advice is to place plants here that are tolerant of low light conditions. The snake plant, Sansevieria, Boston ferns and some palms will thrive and also improve the air quality. NASA ran some tests on many indoor plants to see which showed positive results for cleaning the air of toxins and these all proved to be successful.
Ferns and hostas add wonderful foliage to shady corners and if there is sun higher up, you could plant a climber or even some bamboo which will climb to reach the light. All of these are frost tolerant – just check the label. If in doubt, you can move the planter under cover when the temperature plummets.
Will you be using a watering can or a self-watering system to water your plants? If the planter box is full of succulents, this task is easy peasy because they need infrequent watering but otherwise, you need to consider how to water if the corner box is in a hard-to-reach place.
Soil is the final component of your planter box. Think about the type of plants you intend to grow there. A sunflower will struggle to find enough nourishment in a small corner box but you can certainly plant herbs, which do not have very long roots or any number of colourful annuals.
Indoor corner planter boxes
Tall, metal corner planter boxes can fit nicely into urban indoor corners, their metallic finish contrasts beautifully with green foliage. The size of the planter will determine how tall the plants inside will grow.
A corner box planter on a shelf is a simple, inexpensive way to add some colour to the area. Choose plants to suit the light conditions.
An aquarium corner box planter is a great option if you have a large budget. Many aquarium suppliers offer options to fit a corner box aquarium in your living room.
There are some pretty, fern-like plants available that will add greenery to a lit tank. Buy some water snails in bright colours who will earn their keep by cleaning up the surface of the tank.
Outdoor corner planter box
Keep reading for some DIY options for your outdoor corner planter box.
My favourite corner planters are the tiered corner wooden boxes like the one pictured below. You would need some treated wood to make this and also to line the boxes to make it waterproof.
The top box could house herbs or colourful geraniums, pansies or sweet peas. If you decide on sweet peas, don’t forget that they will climb so add some bamboo supports at planting time.
Another idea is to use flowers that hang over the edge, like trailing petunias. They will offer colour all summer long as long as you keep removing the old, wilted flowers.
For suggestions about which plants to use, see Best plants for a planter box
DIY aquarium corner box planter
Provided that you ensure it is waterproof by using a pond liner, then your outdoor corner box planter could have fish swimming in it and plants such as a dwarf waterlily or a climber.
- Check that fish will survive outdoors. Goldfish, shubunkin and koi are hardy fish.
- Beg, borrow or find. I’ve seen outdoor aquariums constructed from old metal containers upcycled from agricultural or factory use, then painted or decorated after the liner has been positioned. These provide great excitement for children too, who will love to feed the fish and watch them swim.
- If you want to grow something edible, then a watercress plant is a great option. You may want to take a few plants indoors during the winter to ensure you have a ready supply when the weather gets colder.
DIY brick semi-circular corner planter box
Use up any old bricks leftover from building work by creating a shape to fill the corner. Find a corner space outside, where you can place a waterproof liner with bricks to hold it in shape. No cement will be used; the bricks will keep the liner in position and bricks can have some gaps, making an attractive pattern.
- Place a planter box liner to fit the space in the area, allowing extra for the vertical height of all sides of the planter box. You can cut it to fit the actual shape once you have draped the liner over the top layer of bricks
- Lay the first bricks in a semi-circle at the front of the planter box area, with the liner ready behind.
- Make sure all bricks on the ground are touching each other to make a semi-circle to fit the corner.
- Then, pull the liner up behind the bricks, as you lay the second layer of bricks and then a third. By now you have 3 bricks high and you can add soil to the level of the highest bricks. This may be deep enough, or you can add a fourth layer of bricks.
- Ensure that the edge of the liner is now underneath the last row of bricks you lay. Fold it in neatly and lay the bricks on top. This way, the liner won’t show and you can fill the corner box to the top with soil and compost.
- Plant up the box with your chosen plants.
Corner planter box plans
Here are some ideas to download to help you construct your corner box planter: