How to make a window box

Planting up a window box

Whether you have a garden or not, it’s time to give your window sills the glow-up they deserve. Here’s our five-step guide to creating an enviable window box display.

1. Pick your planter

Consider what space you’re working with and decide on the look you’re aiming for. Pick a window box that’ll help you achieve the aesthetic you want (we know, it’s an agonising choice). A long planter or trough that’s centred nicely on the sill will show your display at its best.

Fibreglass and plastic pots are modern and light, whereas terracotta and metal boxes are more traditional. If you’re feeling ambitious, you could even buy some wood from a DIY store and have a go at building your own.

If your windowsill is already wide enough to sit the planter onto, congratulations. There’s no need to break a sweat and you can move straight on to the main event. If not, you’ll need to grab a drill and install hooks or mounting brackets to attach the flower box to your wall before you start thinking about your plants.

2. Check the light

Do some detective work and figure out how much light your windowsill gets during the day so you can choose plants that will thrive there. Does it get full sun for more than 6 hours a day (the dream), or is it in full or dappled shade?

3. Pick your plants

How to make a window box look really good? It’s all in the plants! Once you know whether you’re dealing with shade or sun, the possibilities are vast and you can go wild with your windowbox ideas.

Perennials and bedding plants with a few hanging plants cascading over the edge never go out of style. Alternatively, you could plant up a one pot herb garden right outside your kitchen window, get some pollinator-friendly plants in there to encourage wildlife through the seasons, or even go mono and just use one type of plant, like nasturtiums, to provide a single splash of colour.

Here are our favourite plant combinations and ideas for window boxes:

Herb garden: oregano, mint and basil
Mono-box: petunias, nasturtiums or lavender
Flower-filled: begonias, fuchsias and pelargoniums
Foliage rich: ivy, euonymus and heather
Shade lovers: busy Lizzies, salvias and coleus
Plants for pollinators: lavender, verbena and marigolds

4. Get to work

Slip on your favourite gardening gloves and grab a trowel to plant up your pot. Spread out a few crocks (aka bits of broken pottery) or some gravel in the bottom of the planter to improve drainage, then fill it up with peat-free compost. Pop your plants out of their nursery pots and bed them into their new home. Make sure you top up with more soil and firm it around them.

Styling tip: Try arranging your chosen plants in a linear pattern, giving them room to bulk out. Trailing plants look best in the middle or at either end, with taller, colour-popping flowers and flashy foliage in between. You can either go for a symmetrical look or mix things up for a more whimsical, rustic feel.

5. The finishing touches

A glug of plant feed and a long drink of water will get your windowbox plants off to a flying start. Plants in containers dry out much more quickly than plants in the ground, so set a reminder to water them regularly, especially during those scorchio summer months. Deadhead any flowers as they go over to keep the box looking good for longer and give your plant babies a slurp of liquid feed every week or so to ensure they stay fighting fit.