How to Plant a Beautiful, Thriving Window Box Garden
Improve your chance of success with these tips for choosing, combining and caring for plants in window boxes
Filling a window box with bright flowers and gorgeous foliage plants is one of the quickest ways to give your home a fresh look for the season. If you’re new to window planters, or looking for a refresher on the topic, read on to learn how to choose the best plants for your window box, how to prep your window box, and how to pot up and care for it going forward.
If you’re mounting a new window box, where you choose to put it may also be determined by how much light that spot receives and what you’d like to grow. Window boxes in full sun and partial sun will present more growing options for colorful annuals, perennials and succulents than those placed in partial to full shade.
Learn to build a wood window planter box | Find window boxes
Learn to build a wood window planter box | Find window boxes
This window box grows in full sun and contains red million bells (Calibrachoa sp.), purpletop vervain (Verbena bonariensis), rose campion (Lychnis coronaria) and rosemary (Rosmarinus officinalis).
2. Choose the right plants for your climate. As with choosing plants for any other area in your garden, select varieties that make sense for your climate. Check the plant labels at the nursery, and choose plants that like the same light and moisture conditions to use together.
2. Choose the right plants for your climate. As with choosing plants for any other area in your garden, select varieties that make sense for your climate. Check the plant labels at the nursery, and choose plants that like the same light and moisture conditions to use together.
3. Remember container design essentials. To design dynamic window box arrangements, remember the container rule of three by including a thriller plant, a filler plant and a spiller plant. To put this formula into action, think about choosing one plant for height or as a focal point (the thriller), a plant with a billowing form that will fill up the midsection of the planter (the filler) and a plant to trail down the side (the spiller).
You may choose to nix the tall thriller plant to preserve your view out the window, but all window boxes benefit from fillers and spillers to give that lush, filled-in look.
The Secret Formula for Grouping Plants in a Pot
You may choose to nix the tall thriller plant to preserve your view out the window, but all window boxes benefit from fillers and spillers to give that lush, filled-in look.
The Secret Formula for Grouping Plants in a Pot
This window box grows in partial shade and features tuberous begonia, ‘Gartenmeister Bonstedt’ fuchsia (Fuchsia ‘Gartenmeister Bonstedt’), Scotch moss (Sagina subulata ‘Aurea’), variegated jasmine (Jasminus sp.) and trailing Muehlenbeckia sp.
3. Consider maintenance. Another aspect to think about when choosing plants is how often you’re willing to change your window box plantings. Big billowing annuals like impatiens, million bells and petunia work well for window boxes but often need to be changed each season.
Perennials like geranium, lavender and herbs offer a longer shelf life. Including a small-scale evergreen, such as a dwarf boxwood or cypress, adds four-season interest to the planter, even if you swap out the flowering plants each season.
3. Consider maintenance. Another aspect to think about when choosing plants is how often you’re willing to change your window box plantings. Big billowing annuals like impatiens, million bells and petunia work well for window boxes but often need to be changed each season.
Perennials like geranium, lavender and herbs offer a longer shelf life. Including a small-scale evergreen, such as a dwarf boxwood or cypress, adds four-season interest to the planter, even if you swap out the flowering plants each season.
Window Box Preparation
Before you get ready to plant, check two things.
1. Does your window box have adequate drainage? If your window box does not allow for drainage, either drill holes now or plan on putting your plants in a plastic nursery container with holes and setting the container inside the window box on a raised gravel bed. In the latter case, be careful not to overwater.
2. Is there a moisture barrier inside the box? If you are using a wooden window box, it’s a good idea to line the box with plastic sheeting to prevent wet soil from rotting the box. Line the box with a plastic sheet, staple it in place, trim the top so it doesn’t show and punch holes for drainage at the bottom.
Before you get ready to plant, check two things.
1. Does your window box have adequate drainage? If your window box does not allow for drainage, either drill holes now or plan on putting your plants in a plastic nursery container with holes and setting the container inside the window box on a raised gravel bed. In the latter case, be careful not to overwater.
2. Is there a moisture barrier inside the box? If you are using a wooden window box, it’s a good idea to line the box with plastic sheeting to prevent wet soil from rotting the box. Line the box with a plastic sheet, staple it in place, trim the top so it doesn’t show and punch holes for drainage at the bottom.
How to Plant Your Window Box
After you’ve checked for drainage and added a moisture barrier, if using, you’re ready to plant.
1. Fill the window box, or a nursery container set inside the window box, with fresh potting soil.
2. Mix in an organic or a high-quality synthetic slow-release fertilizer, according to package instructions. This step is optional but will result in fuller, lusher plants in your window boxes.
3. Wet the soil. Check for drainage issues (resolve them by drilling more holes, if needed) and add more potting soil to bring the soil level close to the top of the box.
4. Arrange your nursery plants in the pattern you’d like to plant them in the window box. Keep taller plants toward the back of the planter, move trailers to the edges and fill in the middle with medium-size plants.
5. Dig small holes in the potting soil with a hand trowel or your hand, and place the small plants, removing them from their nursery containers and loosening their root balls, into the soil.
6. After planting, water the window box well.
After you’ve checked for drainage and added a moisture barrier, if using, you’re ready to plant.
1. Fill the window box, or a nursery container set inside the window box, with fresh potting soil.
2. Mix in an organic or a high-quality synthetic slow-release fertilizer, according to package instructions. This step is optional but will result in fuller, lusher plants in your window boxes.
3. Wet the soil. Check for drainage issues (resolve them by drilling more holes, if needed) and add more potting soil to bring the soil level close to the top of the box.
4. Arrange your nursery plants in the pattern you’d like to plant them in the window box. Keep taller plants toward the back of the planter, move trailers to the edges and fill in the middle with medium-size plants.
5. Dig small holes in the potting soil with a hand trowel or your hand, and place the small plants, removing them from their nursery containers and loosening their root balls, into the soil.
6. After planting, water the window box well.
Window Box Maintenance
Watering. Window boxes dry out quickly due to the relatively small amount of soil. It’s best to set up a drip irrigation system either before or shortly after planting to deliver frequent, small amounts of water. Schedule the irrigation system to water the boxes in the morning or evening, when water will evaporate more slowly.
Watering. Window boxes dry out quickly due to the relatively small amount of soil. It’s best to set up a drip irrigation system either before or shortly after planting to deliver frequent, small amounts of water. Schedule the irrigation system to water the boxes in the morning or evening, when water will evaporate more slowly.
Planter boxes installed in hard-to-reach places really benefit from drip irrigation systems. Set up the irrigation to water as much as the plants need, but be careful not to let the soil get too soggy. Few plants thrive in wet soil, and it also presents a greater risk of rotting a wooden window box or, if left wet for prolonged periods, the side of the house.
End-of-season care. Once your window box starts to look tired, pull out annuals and add them to the compost pile. Flowering perennials and perennial herbs, like rosemary, can be transferred to garden beds or left in the window box for another season. Evergreen shrubs and conifers can stay in the window box year-round, as long as they can withstand winter temperatures in your region.
Your turn: Do you have a window box garden? Show us in the Comments below.
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Your turn: Do you have a window box garden? Show us in the Comments below.
More
10 Tips for Beginning Gardeners
Size Matters: How to Choose the Right Plant Container
Find a landscape professional in your area
Browse more window boxes
1. Know your light exposure. Before you jump into the fun part — picking out the plants for your window box — take a good look at how much sunlight the window box receives. This will dictate which plants will thrive in the spot.
Take a look at the window box multiple times a day. Does it receive morning sun (partial sun, partial shade) or afternoon sun (partial sun, partial shade but often hotter than morning sun) or four to six hours of sun (full sun) or very little sun (full shade) all day? Choose your plants at the nursery accordingly.