How to Plant Flowers: Step-by-Step Guide to Planting a Window Box

This summer, make your home’s exterior bloom and learn how to plant flowers in window boxes! (If you don’t have window boxes yet, check out this tutorial on how to make your own for an easy DIY window planter box!)

Planting a Window Box

If you’ve always wondered how to achieve that professional and luscious look in a window box but aren’t quite sure how, this tutorial on how to plant flowers on a window planter box is for you.

We’ll show you step-by-step photos and give you tips to help you on your way to creating the most beautiful window box planters on the block.

How to plant flowers in a planter box

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This photo represents only a week or two after planting – similar to what the box will look like when you plant.

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Top Tips for Planting a Window Box Planter

Before we get started, we want to share with you a few of our top tips regarding the soil in your window box. As you’ll see below, we use potting mix for this project today.

You’ll want to avoid just using potting soil in your window planter boxes, as this soil will quickly lose the needed water and nutrients for your window box plants.

One thing to keep in mind is to never add organic material into your soil, such as wood chips or straw. You can add it onto the top if you want, but it shouldn’t go into the soil itself.

Window Box Planting: How to Create a Beautiful Plant Window Box for Your Home

Step 1 – Empty Your Window Box from the Past Season

If you have used your window box planter during the past season, now is the time to empty it out.

Get rid of all the soil (you don’t have to throw it out, though – toss it into the garden or a flower bed) so you’re starting fresh.

It’s important to use fresh soil each season for optimal flower growth.

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Step 2 – Get Your Potting Mix

Grab your sack of potting mix. Note that this isn’t the same as potting soil.

Potting soil is specifically designed for areas such as flower beds, while the potting mix is designed for things such as planters, hanging baskets, and window planter boxes.

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Step 3 – Fill Your Window Planter Box with Potting Mix

Fill your window box planter to 1”-2” from the top edge with the potting mix.

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Smooth out the potting mix, pressing gently to remove air pockets.

Ensure it’s nice and evenly spread throughout the window planter box, to give your plants the best environment to grow.

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Step 4 – Decide on the Arrangement of Your Plants

For spacing purposes, arrange your plants (still in their pots) in the order you think is most attractive.

Don’t be afraid to move things around, group them together, spread them apart– whatever looks balanced and appealing.

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Step 5 – Transfer the Arrangement onto the Ground

Transfer this arrangement onto the ground, in the order that you determined looks the best. For your reference, this tutorial’s window box planter is about 4’ long, 5” wide, and 6” deep.

We planted four wave petunias, four geraniums, one creeping Jenny, and one sweet potato vine, all in 4” pots, for a total of ten plants as these are the best plants for a window box.

This may seem like a lot, but the trick to a beautiful, luscious window planter box is packing them in.

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Step 6 – Begin Planting Your Flowers and Plants

Start on one end of your box and begin planting, following the layout you’ve created on the ground nearby.

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When you pull a plant or flower out of its pot, it’s helpful to gently break apart the bottom of the root base– this is the most important tip you need to keep in mind when learning how to plant flowers.

It’ll probably make a ripping sound, and you might feel like you’re damaging the plant.

But the truth is, you’re liberating the roots so they will grow and expand faster in their new home than they otherwise would.

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Step 7 – Stagger the Plants Throughout Your Window Planter Box

Stagger the positioning of your plants’ placement of front-to-back.

By this, we mean if you want your taller flowers to fill in the back of the window box planter (in this case, geraniums), don’t be afraid to plant them closer to the back of the window planter box.

The plants don’t need to be exactly evenly spaced apart.

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As you can see, we planted the “back” row (geraniums) first, leaving enough space in the “front” row for the other plants.

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Step 8 – Fill in the Front Spaces of Your Window Box

Fill in the front spaces.

The order we used (staggered front-to-back in the window box planter) from left to right was: wave petunia, sweet potato vine, geranium, wave petunia, geranium, wave petunia, geranium, creeping Jenny, geranium, wave petunia.

Pro Tip: Take note of these plants as these are the best plants for window boxes or as what others prefer to call, the evergreen window box plants.

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Step 9 – Weave Your Soaker Hose Through the Plants

Carefully weave your soaker hose among all the plants, taking care that each plant has water access.

This detail is key to thriving window planter boxes – if they are not on an automatic watering system (soaker hose connected to a drip sprinkler, for example), by mid-summer your plants will likely be drying out and struggling.

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Stake the end of your soaker hose down with a landscape staple.

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Step 10 – Make Any Final Adjustments to Your Window Box Planter Display

Make any adjustments you think you need at this point, either to the soaker hose or the plants themselves.

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Step 11 – Add Extra Potting Mix as Needed

Add in the extra potting mix where needed.

We try to aim for the dry potting mix level to hit about 1/2″-1” from the top of the box because when water is added, the potting mix will compact a bit.

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You’re close to being done (we’re sure your window box looks beautiful at this point!), but there’s one final step to help your professional-looking box flourish.

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Step 12 – Add Fertilizer to Your Window Box

Get your hands on a fertilizer that focuses on root growth and blooming.

We use this Fertilome Blooming & Rooting fertilizer with great success – it helps with root growth, water retention in the potting mix, and slow-release fertilization over several months.

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Dilute it with water as per instructions and pour the fertilizer thoroughly over the plants in your window box.

Now just water regularly (every day or two, hopefully via your automatic system) and fertilize with regular flower fertilizer a couple of times a week.

A good rule of thumb for sufficient watering in a planter window box is water until you see water dripping through the holes in the bottom of your window box, so you know the potting mix is sufficiently saturated for that day.

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This photo shows the window box plants about 1.5 weeks after planting. Sunshine and warm temperatures had been scarce during that time, so the plants are maintaining but not expanding.

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This photo shows the plant window box about four weeks after planting.

Warmer temperatures helped the geraniums bloom and the petunias explode. The creeping Jenny and sweet potato vine (trailing plant for window boxes) should follow suit.

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We were so pleased with how this window box turned out, and we love the pop of color it adds to the exterior of the home.

It’s such a simple project, and creating your own window box planter is very easy to do as well.

A window planter box is so easy to refresh each season, and you can add new flowers and plants to keep up with the changing colors. For anyone with only a small garden space, you’ll still be able to add extra flowers to your home this year without taking up much room at all.

Colorful blooms make any space a pretty one, and a window box is no exception. (Want more? Check out our tutorial for planting bloom hanging baskets.)

Happy planting!

The best plants for window planter boxes

You’d think building the window planter box is the hardest part of this sort of project but choosing what plants to fill it with is not an easy process either.

To help you out we did some research and found out what the best plants for window boxes are.

Petunias

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This is one of the most colorful and beautiful plants for the summer season.

It makes these vibrant blooms which can be white, red, pink, or purple, and which you can combine if you want a multicolored display for your windows.

Coleus

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The coleus plant is a lovely choice if you want some color but you’re not that fond of flowering plants.

Its leaves look magnificent and are famous for their red and purple colors and their beautiful patterns.

They look gorgeous in window planter boxes and they’re great filler plants if you want to combine them with something else.

Creeping Jenny

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Speaking of filler plants and beautiful colors, the creeping jenny is absolutely magnificent.

It cascades down from window boxes and planters and has these lovely penny-shaped leaves in a really vibrant shade of green.

Sweet potato vine

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Another great option for those who love foliage and interesting colors is the sweet potato vine which comes in several different varieties.

The green and purple variants are really beautiful and stand out without being too bold about it.

Dusty Miller

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The dusty miller plant is famous for its exquisite silver-colored leaves which look like they’re frosty but also have this soft and delicate look as well.

They don’t grow very tall and they do well in the heat or with limited water which means keeping them healthy is not demanding at all.

Snapdragon

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The Snapdragon flowers are vibrant and eye-catching and they grow quite tall so they’re a nice choice for window planter boxes because you can see them from inside.

This is a summer plant so you might want to combine it with a few other ones if you want color all year round.

Fuchsia

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The fuchsia plant, just like the color, is bold and eye-catching.

Its flowers feature a magnificent combination of bright pink and purple which stand out in any context. It doesn’t like to be exposed to full sunlight so avoid putting it in sunny window box plants that don’t get shade throughout the day.

Impatiens

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A lot of flowers and plants don’t enjoy being exposed to the full sun which can be a problem in some cases. However, shade is not easy to deal with either.

The impatiens plant is one of few which thrive in shaded areas and also makes colorful flowers too.

Verbena

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Another eye-catching plant is the verbena which makes these bright pink and purple flowers with stripes on the petals that make them look like little candy canes.

They look delicious and they’re a great fit for window planter boxes because they have a cascading appearance.

Licorice

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The licorice plant may not be very colorful but it stands out differently.

It’s famous for its felted leaves which look super soft and fuzzy and have this subtle white overlay that dims their green color.

There’s also another version which has yellow tones.

Variegata

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This plant is also known as variegated ivy and is a wonderful choice for window boxes especially if you want something that will cascade down and that’s also super easy to maintain.

It’s not fussy about sunlight and it’s also drought-tolerant so you don’t have to worry about it too much.

Ornamental grass

Ornamental grass

In addition to all these fancy and colorful flowers and plants for window boxes, there’s also another type that might appeal to you differently: ornamental grass.

You can use it as a filler plant or just to add texture and color to a window box.

DIY window box planter ideas:

Off-the-shelf window boxes are definitely convenient but don’t really offer much in terms of originality and customization, not if you want something very specific.

They’re also usually designed in standard sizes so you might have trouble finding one that fits.

Luckily there’s always the DIY route.


A lattice window box

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This is such a simple design but it’s also a beautiful beautiful one.

The lattice window boxes featured on prettyhandygirl are deep enough to allow the plants lots of room to grow and simple enough to allow the focus to be on the greenery.


A simple wood window planter box

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Wooden window boxes are perfect for giving the exterior of your house a homely and inviting look. If the windows have shutters, that is a wonderful opportunity to add planters that match those.

A lovely example in that sense can be found on beneathmyheart.


Extra-long window box

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As mentioned before, off-the-shelf window boxes have certain standard dimensions which means if you want something super long you’ll probably have to build it yourself.

This extra-long box design from twotwentyone is great if you have double or triple windows and you want to unify them and keep the décor simple on the outside.


Pallet boxes

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Reclaimed wooden pallets are an excellent resource for lots of DIY projects, including these lovely window boxes from paradiseperspectives.

Use the pallet wood if you want to keep the cost of the project low but also if you want to give the boxes a rustic and worn look for more authenticity.


Simple stained box

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Isn’t this window planter just charming? The one featured on shanty-2-chic is perfect for this old brick house because it almost blends in.

That really helps the brightly-colored flowers and leaves to stand out more and to look absolutely dreamy.


A design to match the window

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Window boxes are not necessarily designed to be placed under the windows but if you do choose to do it this way perhaps it would be nice to go with a matching design.

You can make your window planter boxes match the windows in color and style, like this one from remodelaholic does.


Mini fence planter

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Does this window box from makeit-loveit remind you of picket fences?

Well, that’s because it was made from cedar fence planks.

If you don’t want to build it from scratch you could choose instead to decorate an existing planter with some cut fence boards.


Chevron boxes

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If you already have some window boxes that are still in good shape there’s no reason to replace them yet.

You can instead just give them a makeover. How about this cool chevron pattern idea from addicted2decorating?

It’s pretty easy to get right and you can have a lot of fun combining colors and creating an interesting design for it.


Scrap wood planter

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Scrap wood, whether it’s from a pallet, some old fence boards, or leftover pieces from previous projects, is a great resource for window boxes and planters in general.

This simple design from instructables shows you how to emphasize its beauty and uniqueness.

First, you make a simple box, then you decorate the front with boards of different sizes, shapes, and colors.


A design that blends in

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The window planter boxes themselves don’t need to stand out too much. It’s actually the contents that get that privilege.

With that in mind, you might want to come up with a design for your DIY window planter boxes that allows them to blend in and look natural underneath your windows.

The design featured in this tutorial on construction2style seems just right.


Window Planter Tips

How to hang window planter boxes?

Here is an easy step-by-step guide on how to hang window planter boxes:

  • Measure the window frame where you want to hang your window planter box and mark the spots where the brackets need to be. 
  • Drill holes in the marked spots.
  • Attach the brackets to your window frame with screws and secure them firmly in place. 

Hang your planters from the brackets and start planting your flowers.

How to plant in a window box?

The detailed steps on how to plant in a window box can be found in the tutorial above but here’s a quick recap:

  • Pick a window planter box that complements your window or if you have one from the past season, simply clean it out. 
  • Fill your window box planter with soil that is appropriate for your chosen plants. 
  • Carefully plant your flowers on your window planter box. 
  • Water the plants and add some fertilizer.

What plants are good for a north-facing window?

Plants best suited for north-facing window are those that thrive in shaded areas. These include the following:

  • Snapdragon
  • English daisy
  • Cardinal flower
  • Wax begonia
  • Astilbe
  • Creeping myrtle 
  • Fuschia

Frequently Asked Questions (FAQ)FAQ

Are north-facing windows good for plants?

North-facing windows are good for plants that thrive in low-light environments, thus, it is the best spot for shaded window box plants.

What window direction is best for plants?

The best window direction depends on the type of plant you have and its light preference. For you to be able to best determine which window direction works best for your plants, you first need to know if you java trailing plants for window boxes, shade plants for window boxes, or sun-loving plants.

What to plant in window boxes?

You can find a list of the best plants for window boxes in the tutorial above but we prefer planting begonias, zinnias, and petunias as main-theme flowers, with vinca and ivy planted over the edge of the window planter box.

How many plants per window box?

The number of plants you can put in your window planter box depends on its size but aesthetically speaking, you should keep your plant and flower choices to a maximum of three. Nevertheless, it’s still up to you and your preference.

Can you grow plants in a north-facing window?

Absolutely yes! But you have to keep in mind that plants that love indirect sunlight or those that are shade-loving are the ones you should put in a north-facing window.

What plants can survive in a bathroom without windows?

Some of the plants that can survive in a bathroom without windows include aloe vera, peace lilies, English ivy, and snake plants.

What to plant under front window?

The following are some of the best plants for window planter boxes placed under the front window that can instantly add that luscious curb appeal: coleus, petunias, creeping jenny, Fuschia, verbena, licorice plant, purple prince zinnia, and salvia.

Does window film affect plants?

Window films do not generally affect or harm plants even if your plants are indoors or outdoors.

What size window box planter is the best option?

The size of your window planter box ultimately depends on how big your windows are since its length should complement the length of your window.

Another thing to consider when choosing the perfect size for your window box planter is the number of plants/flowers you’re planning to use.

The depth of your window planter box should be appropriate to the number of plants you’re going to put on it since you need to have enough room for those plants to grow.

Conclusion:

Well, there you have it! Everything you could possibly want to know about window boxes.

Now that you’ve learned how to plant a window box and found a few ideas for plants and design, you’re ready to turn your windowsill into a lush green garden.r

No matter where you live, whether it’s in a house or an apartment, or even a hotel room, there is no reason for you not to be able to create your own flourishing garden. All you need is the right planter, tools, and plants. Once you have those things, all that’s left is to get down to work.