5 of the best flowers for window boxes to brighten up your home's façade

Wondering what's the best flowers for window boxes? You're in the right place.  Window boxes are a sure-fire way to boost your home's curb appeal, brighten up your outside space and make use of an otherwise unused area of your home. 

But where do you start? Introducing a kaleidoscope of color, adding wildflowers and growing your own are all having a major moment in the container gardening world. But just like when it comes to adding a welcomed pop of color to any part of your outdoor space, there's a lot to think about. 

To discover all this and more, keep reading. We've put all the questions to the experts to find out what's the best flowers for window boxes. 

What are the best flowers for window boxes?

Firstly, do you want your plants to bloom all year round? Or are you partial to a perennial? You'll also want to consider how much sun and shade your plants will get, along with how tall they'll grow (remember: you'll want to be able to see out the window), and how often they need watering. 

1. Plant annuals like petunias

If you’re after all-year-round color, then consider planting annuals in your window box.

‘Annuals are probably best for color as they bloom all season long as compared to perennials that go in and out of flower throughout the season,' Diane Blazek from the National Garden Bureau tells us. 

Perhaps the most common flower trend spotted blooming in window boxes is the much-loved Petunia. The bright and beautiful florals are a sure-fire way to add some color to the outside of your home. But just be warned: the annual flower loves regular watering and sunlight. 

2. Opt for perennials like geraniums

Easy to grow, easy to love and easy to look after, geraniums make for popular options in hanging baskets for more reasons than one. 

The vitamin D-loving flower, which is more informally known as cranesbills, is believed to have more than 422 species and it comes in a variety of shades, including red and white, orange and yellow, pink, violet and lilac, so there's something to suit every modern front garden color scheme. 

For other sun-loving plants, Blazek recommends adding, ‘calibrachoa, geraniums, snapdragons, verbena, lantana and shorter varieties of zinnias and marigolds.’

3. Try herbs like rosemary 

Don't have room for a herb garden? Create your own herb garden from your window sill. Coming in handy for cooking, adding rosemary to your window box will give your sill a hit of greenery and leave a pleasant aroma for anyone walking by. Plus, it's also ideal for all those living the good life with a small backyard. 

‘Some herbs like basil and rosemary are good fillers and oregano and thyme as spillers,' Blazek says. Or learn how to grow cilantro for another window box addition. 

4. Fill your box with fuchsias

Does your window box get more shade than sun? Consider adding bright and beautiful shade-loving florals to your window with a perennial like the much-loved fuchsia. 

The exotic-looking flower, which looks like little hanging lanterns, tends to trail (although they can grow upright with a little bit of TLC) making for the perfect addition to hanging baskets. 

Blazek says for other shade-loving options, try, ‘Coleus, impatiens, caladiums, begonias and perennials such as astilbe, ferns and hostas.’

5. Try fillers, like ivy

It’s not just flowers and herbs that you can fill your window box with. To help decorate the space and add some greenery to your window sills that will improve your home's curb appeal, consider adding evergreen fillers to your box. 

According to Blazek, ‘Sweet potato vines, ivies, vinca minor, creeping Jenny, and other trailing foliage or blooming plants’, would work well. 

How many flowers should you put in a window box?

‘There are two things one needs to know first in order to figure out how many flowers are needed,' Blazek says. 'First, what size (height and width) are the flowers you wish to use? Secondly, how long and deep is your window box? 

‘For a window box, you can position each plant closer together than what the tag or label suggests. Just know that some plants are more aggressive growers so they may outgrow their neighbors. 

'A little trial and error goes a long way in learning what works best together but to start, and in general terms, you can place one plant every 6” in a window box, going right to the ends to really make the box look full and lush.’

How can you keep flowers alive in a window box? 

Once you’ve gone to all that trouble of finding the right flowers for your window box, it’s now time to think about their aftercare. 

To help keep your flowers alive, Blazek recommends thinking about three things. This includes: 

1. Know the amount of sun your window box will get. 
2. Water the right amount depending on the amount of sun and the types of plants but make sure the window box has good drainage.
3. Fertilize blooming plants for season-long flowers.