Now summer is upon us, we’ve written you the ultimate guide to the best plants for window boxes ahead. After all, pretty-planted windowsill displays are an easy way to give your home an instant uplift. We’ve recruited help from Modern Gardens Magazine contributor Louise Curley to help with choosing the best outdoor plants for your home, as well as the right containers to house them in.
Similar to hanging baskets, window boxes offer a splash of green, a splash of colour to an area that may have previously been dull. You could even add matching boxes to both upstairs and downstairs sills for more impact. As you all may know, flowers clean the air of harmful toxins and can improve our wellbeing. Not only will your picks look fresh, but they will freshen the air, also. All the more reason to hang a window basket outside your bedroom window – next to your house plants.
Best plants for window boxes at a glance:
• Neon-like coloured blooms: Nemesia 'Sunmesia Tropical'
• Star-shaped violet flowers: Campanula carpatica
• Best plants for summer window box: Flowers for a Summer Window Box Collection
• Unusual flower pick: Pelargonium 'Australian Mystery'
• Marirgold-esque saucers: Arctotis × hybrida hort. 'Orange Prince'
Finding the ideal plants for your window box project doesn't have to be a tricky task. First, the window box you should choose very much “depends on the type of windows and sills you have,” says Louise. When opening your window, you don’t want to damage your plants – and having easy access for watering and general maintenance is preferred. Before you buy, make sure to check if your windowsill is wide enough to take a hook or bracket to secure the window boxes.
Louise reminds us that compost will weigh the planters down, so invest in separate fixings for security. Another drawback of window boxes: “bear in mind that water draining from the box may discolour your sills or walls,” says Louise. So, consider using one with a drip tray underneath. This way, your beloved plants won't be causing any issues - and will look healthy and make a world of difference to your home.
Best plants for window boxes
For a delightful springtime or summer display, we have found the best plants for window boxes.
Vibrant hues
For colour from June to September, pack your window box with a selection of long-flowering plants.
Dazzling red flowers
www.sarahraven.com
Add one petunia ‘Tidal Wave Red Velour’, which has big saucer-like blooms, at each end and one in the middle.
Neon-like coloured blooms
www.sarahraven.com
Put two nemesia ‘Sunmesia Tropical’, which has almost neonlike coloured blooms, in-between the petunias.
Star-shaped violet flowers
www.crocus.co.uk
At the front, add a Campanula carpatica, which will form masses of sparkling star-shaped violet flowers on a bed of long-stalked rounded leaves.
A light touch to darker flowers
www.thompson-morgan.com
Fill out the spaces with compact foliage plant Senecio cineraria ‘Silver Dust’. Its silvery leaves will add a light touch to the darker tones of the flowers.
Beautiful purple flowers
www.waitrosegarden.com
At the back, plant three osteospermum ‘Sunny Mary’, which will dazzle with their beautiful magenta daisy-like flowers that grow atop deep green foliage. They grow up to 30cm, too.
Soft and floaty
If you’d prefer something a little wild looking, try this combination of Mexican fleabane, with its frothy haze of white and pink daisy flowers, and the soft pompom-like, vibrant green blooms of sweet William ‘Green trick’, says Louise.
Best plants for summer window box
www.sarahraven.com
They come as part of the Flowers for a Summer Window Box Collection. Both of these plants should keep flowering, with a little protection from wind and rain, until the end of November. Pop the 'Green Trick' around the widnow box border, fill the centre with the fleabane and allow for overlap. Water wit a full can at least once a week.
Keep the container sheltered over winter and the fleabane will regrow next spring.
Simply stylish
Pelargoniums thrive in a sunny spot, says Louise. "They will flower from May to the first frosts and need very little attention." Luckily, they come in a variety of colours to suit all tastes. These range from "pretty pastels to rich jewel-like colours, and some, such as Brunswick, have a heady, fruity scent". You can also choose from trailing ones that are referred to as ‘ivy-leaved’, such as the Double Trailing Black.
Unusual flower pick
www.sarahraven.com
Plant five pelargonium ‘Australian Mystery’ in a straight row. If the box is quite large, use as many plants as you need to fill it out. It has rich contrasting purple wings, a bright and pretty splash of white in amongst the rest.
Tall, proud and elegant plant
www.sarahraven.com
Fill out the back space with tall Gypsophila elegans. This simple gypsophila could not be more different to the twee, top-heavy double form often used in flower arranging. It'll need decent drainage, though.
Pretty peach
Trailing black-eyed Susan will envelop any container, which is "perfect if you want to cover an inexpensive plastic window box", says Louise. It flowers from June right through until the first frost.
However, Arctotis ‘Flame’ provides height as it grows to about 40cm with "slender stems topped with flame-coloured exotic blooms" from May to October.
Sunset annual climber
www.sarahraven.com
Black-eyed Susans are fantastic annual climbers, flowering hard until your first hard frost. This Thunbergia alata 'African Sunset' variety has flowers in all the colours of a spectacular sunset.
Marirgold-esque saucers
www.sarahraven.com
We love these marigold-esque flowers. The Arctotis × hybrida hort. 'Orange Prince' are delightful - with orange saucer-sized flowers with incredible centres.
FAQs
What are the best window boxes?
When choosing a window box, Louise has some suggestions. This may seem obvious but is an essential step: Make sure to measure your windowsill so your box can fit. After all, you don’t want to have to fuss around with returns. We’ve included dimensions in our top picks. Not to worry.
Louise says to “always buy the largest and deepest planter possible that fits the space.” A larger planter won’t dry out as quickly. Also, “there’ll also be plenty of space for roots to grow making healthy plants and a more attractive display.” Sounds ideal, right?
We’ve avoided listing plants that are tall, bulky or top-heavy. “If you have windows that open outwards you may need to stick to low-growing plants,” says Louise. However, if you have windows that open upwards “you can experiment a bit more using slightly taller plants.”
How do I plant a window box?
Louise Curley has a step-by-step guide on how to plant a window box.
First, Create Drainage. By adding a layer of broken pots to the bottom of the planter, you can help with drainage. After all, window boxes need plenty of drainage holes as “waterlogged compost will cause your plant’s roots to rot.” So, Louise suggests checking when you shop or adding holes by drilling.
Next, Fill It. According to Louise, this should be about halfway with compost that has added plant food. For example, Miracle-Gro All Purpose Compost may serve you well. This way, plant food is “continuously released, keeping your plants fed… for up to three months.”
After this, Plant Up. Create your own design by carefully tipping “out the plants from their pots and position in the planter.” When you’re happy, fill the gaps around the plants with more compost “and firm it down with your own hands.” Avoid overspill by keeping the compost lower than the rim.
Lastly, Water It. This should be done thoroughly, says Louise, so that “water runs out of the base.” Remember: water boxes will dry out quickly. To avoid any issues, check the compost every couple of days, “more frequently in hot weather,” says Louise. If it feels dry, water it with half a watering can.
Top window box pick
www.crocus.co.uk
This Sage Hanging Metal Planter from Crocus may help. it's ideal for fences, balconies, walls and railings. It's made from powder-coated steel for long-lasting plant protection against the elements.
Pros
- Pretty green colour
- Powder-coated steel for long-life
Cons
- No customer reviews
| Dimensions | L33cm x W16cm x H14cm |
| Base | L29cm x W12cm |
| Material | Powder-coated steel |
| Capacity | 7L Compost |
| Hooks | Two |
Perfect for kitchenside herbs
www.crocus.co.uk
Perfect for plants and windowsill herbs, this window box is perfect for brightening up a space. It features a matching saucer which clips onto the base and allows for easy, convenient watering.
Pros
- Made from recyckled resin
- Waterproof, non-porous and UV-stable
Cons
- No customer reviews
| Dimensions | W26cm x H17cm |
| Base | L47cm |
| Material | Lightweight recycled resin |
| Capacity | Unspecified. |
| Hooks | Rack, up to 6cm wide |
Ornate, cottagecore box
www.crocus.co.uk
This Stratford Window Box may have the appearance of traditional wrought iron, but is made from a guaranteed rust-proof material: recycled glass fibre-reinforced resin. It comes flat-packed but is easy to assemble.
Customer Review: "Super, traditional looking wrought iron style but with the plus point of being lightweight and maintenance free."
Pros
- 100 per cent recycled
- Quick and easy assembly
Cons
- Assembly is required
| Dimensions | W21cm x H23cm |
| Base | L81cm |
| Material | Recyled glass fibre reinforced resin |
| Capacity | 1.4L |
| Hooks | Wall Brackets |
Budget wall basket
www.wilko.com
Wilko's Sage Large Metal Wall Basket with Liner adds a style to your garden. Fill these baskets with your favourite flowers, herbs or plants and watch them grow. Perfect for your window or even a wall.
Customer Review: "Very well made plant troughs in a lovely shade of green with lining included. Arrived in good time and exactly as advertised. Two holes at back so can be fixed directly to the wall or onto hooks. Very pleased with my purchase of three of these troughs."
Pros
- Sturdy, metal design
- Adds instant style
Cons
- Need replament liners
| Dimensions | H16 x D19.5 cm |
| Base | L70cm |
| Material | Metal, Fibres |
| Capacity | Unspecified. |
| Hooks | Unspecified. |
15.
Metal Window Box
Sturdy, metal planter
www2.hm.com
This window box is painted metal. It comes with a hanger, so you can attach it to a balcony rail or trellis. This is perfect if your green space is a small one. With three drainage holes in the base, it's a solid choice.
Customer Review: "Already have 3 of the smaller black ones which have been out in the garden for nearly two years now. Just stunning and really well made."
Pros
- Other styles available
- Great size and depth
Cons
- Unspecified capacity
| Dimensions | H16.5 x D13 cm |
| Base | L47cm |
| Material | Metal |
| Capacity | Unspecified. |
| Hooks | Two |
Antique slate window box
www.thompson-morgan.com
We love this decorative, durable planter from Thompson & Morgan. This Anaheim premium Window Box is made from 100 per cent recycled plastic with pre-located drill points for drainage. How handy is that?
Pros
- Made from recycled plastic
- Vinatge, antique look
Cons
- No customer reviews
| Dimensions | H23 x W 25 cm |
| Base | L51cm |
| Material | Recycled plastic |
| Capacity | 20L |
| Hooks | Unspecified. |
Best ceramic window box
www.crocus.co.uk
Finally, we have this Aged Ceramic Trough from Crocus. Glazed, it has been cleverly distressed and aged to give it a vintage Victorian feel. This trough is completely frost-proof and perfect for filling with plants.
Pros
- Vintage Victorian feel
- Frost-free glazed ceramic
Cons
- No customer reviews
| Dimensions | D15 x H16 cm |
| Base | L39.5cm |
| Material | Ceramic |
| Capacity | |
| Hooks |
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Piper Huxley is a Homes, Garden and Wellness Product Writer for Modern Gardens Magazine, an all-rounder. When she’s not writing about houseplants, she’s tending to her own growing collection…