Window Fleur garden window box tutorial

How to create a beautiful DIY window planter box for summer

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Filled every corner of your home with greenery? There’s one space you might not have thought of – your windowsill. Read these expert tips from the founder of Window Fleur on how to make your own garden window box.

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When the weather is warm, it feels wrong to be sat inside all day. But, unfortunately, lots of us have to do just that during the week. But, as people have realised over the past year or so, there are many ways to make the four walls we stare at day-to-day feel a bit more exciting, including bring some of the outside world indoors.

From hanging planters to our ceilings, to sprucing up supermarket herbs and finding corners of our homes we didn’t previously know were there to fill with fresh flowers, we’ve found lots of new ways to start injecting more greenery into our homes during lockdown.

One area you might not have considered decorating – but one that nearly everyone has access to – is your windowsill, which is the perfect space to try your hand at some outdoor gardening if you don’t have a garden or a balcony. Garden window boxes are great because they improve the appearance of your home both from the outside and the inside and can be fairly low-maintenance if you plant them properly.

Frannie Liddle and her cousin Joe Revell realised that window planter boxes could be a great solution for those looking to up their greenery game. During the first lockdown in the UK, they founded Window Fleur, a garden window box delivery company. Frannie is a trained florist and creates a variation of boxes to choose from each season, including a herb box and a box that helps to support bee habitats. “Curating the plants and making sure people get a really nice selection is my favourite part of my role,” Frannie says.

Frannie has shared her expert tips and recommendations for anyone looking to create their own garden window boxes at home, including how to curate your plants for each season and how to keep them alive

White garden window planter
Founder of Window Fleur with window planter box
garden window planter box pink flowers
Window Fleur create postal garden window boxes, How to make a garden window box with Frannie Liddle, A garden window planter tutorial

What you’ll need to create your window planter box

  • 1 planter box to fit your windowsill (Window Fleur boxes are 90-130cm)
  • 1 bag of multipurpose compost (ideally peat-free)
  • Your preferred plants

How to fill your window planter box

  1. Fill your pot with compost, leaving a 2cm gap between the top of your compost and the rim of the pot.
  2. Leaving your plants in their pots, arrange them in the container, with the tallest plants in the centre and smaller plants around the edges.
  3. When your happy with the layout, remove all of the pots and plant.
  4. Fill in any gaps with compost and push it down with your fingers.
  5. Place it on your windowsill in an area with a decent amount of light exposure.
  6. Thoroughly water your plants.

Frannie’s plant recommendations

Frannie has spent a lot of time curating plants for Window Fleur, so she knows just what kind of combinations will work together for each season. “I advise that you buy boxes of bedding plants,” she says, explaining that they will only last up to one year but they work really well in window boxes so they’re worth the investment. If you can, Frannie recommends changing your plants up each season, in order to get the most out of them in terms of growth and appearance.

Her plant recommendations for each season are:

Spring: primroses and bell daisies

Summer: verbena, begonias, calibrachoa

Autumn: calluna, skimmia japonica

Winter: hellebores, ivy, erica darleyensis

You can also grow herbs in your window planter by simply planting the herbs of your choice in your box (supermarket herbs will work just fine). You can even grow fruits and vegetables in your planter, if the weather allows for it, in the same way you would usually grow fruits and vegetables outdoors.

Window Fleur has a special box in collaboration with Burt’s Bees which is dedicated to helping boost the bees’ natural habitats by using pollinating plants. If you want to use your box to help attract and look after wildlife, opt for plants like borage and coneflowers.

Frannie’s expert tips for making beautiful window planter boxes

Frannie Liddle watering garden window box
Frannie Liddle with garden window planter
Window Fleur offer seasonal garden window boxes, Frannie is the co-founder of Window Fleur

Pick a box that suits your interiors styles

“There are so many different containers to choose from, whether that’s a traditional terracotta pot or a simple metal one,” Frannie says. She explains that you should pick a container that suits your interiors style and also keep in mind the kind of plants you’re going to fill it with, so you can make sure they compliment each other.

Work out a good drainage system

Depending on where your windowsill is placed, your box might need a form of drainage system. Adding a layer of gravel to the bottom of your box is always a good idea, Frannie says, adding that, “if your window gets a lot of rain, choose a plot with drainage holes or add some in yourself.”

If you’re worried, secure your planter to your windowsill

If you use a heavy box, made out of metal or ceramic, it’s unlikely to slip from your windowsill but there are some things you can do to make it more secure if this is something you’re concerned about. Window Fleur boxes come with detachable arms which will help keep your planters in place. You could create a similar effect by placing a security wire around your planter, or using some kind of bracket to keep it in place.

Make the most of the summer months

“During the winter months and some of spring, you don’t have lots of choice in terms of what you can plant and your plants won’t grow much during these seasons either,” Frannie says. It’s therefore crucial to really make the most of your window planter in the summer, taking care to put more effort into looking after it than normal and maybe investing more money into your plants during the warmer months too.

Tailor your maintenance plan to the weather

The main thing you need to do to look after your planter boxes is to water them regularly. Frannie recommends doing so every other day, as a rule. If the weather has been particularly hot, you might need to water them more. If it’s been rainy, then your plants won’t require as much water. You should also do some research on the specific plants you’ve chosen in order to figure out how much water the specific plants you have chosen need. 

The other thing that Frannie recommends you do to look after your plants is regular deadheading, which means keeping an eye on your plants and removing any parts that are dying in order to encourage more healthy blooms.

“And then as soon as the weather conditions change seasonally, it’s best to replace your compost and your plants,” Frannie adds.

  • Frannie Liddle, co-founder of Window Fleur

    Frannie Liddle in garden
    Frannie Liddle's expert tips on creating a garden window planter

    Frannie is a trained graphic designer who after a number of years in industry founded her own design studio in 2016. She later went on to train as a florist before co-founding Window Fleur in 2020.

Images: Window Fleur

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