Expert Tips for Growing a Window Box Garden

Casey Lawrence’s lush window boxes were a revelation to her online followers. Use her tips to grow your own.

window boxes with lush purple flowers and grasses
Photo: Bob Stefko

Casey Lawrence grew up in the vegetable farm and garden center biz. Today, she spreads the joy she finds cultivating a plant-based lifestyle in southeast Wisconsin via The Lawrence Garden Farm website and social channels.

Casey's lush window box displays are a follower favorite. This exuberant design features orange canna, dragon wing red begonia, superbena large lilac blue verbena, wave petunias, 'purple knight,' liberty classic bronze snapdragons and vertigo grass. Here are her tips for creating your own window box garden designs at home, plus how to care for them.

Provide Adequate Light

Window boxes became popular in ancient Rome, where cramped city dwellers had no room for gardens. If you do as the Romans, pick a window that gets plenty of direct sunlight—most blooming annuals need at least six hours per day. Casey's boxes face east, but south or west works too.

Choose a Large Box

The bigger the box, the better—plants need space to develop good root structures. Casey's boxes measure 12 inches tall and deep. "The more space you have for roots to grow, the larger things get, and the more showy they get," she says. Include drainage holes so roots don't rot in wet soil.

Start Fresh

Remove any old soil from the box, scrub the box clean and fill with fresh potting mix. Blend in a slow-release fertilizer per manufacturer's directions. And leave 1–2 inches between the soil level and the top of the window box so you can plant and water easily. "This step is crucial," Casey says.

Water Often

Check the soil regularly for dryness. Casey waters every seven to 12 days in the first month, then five to seven by mid-July when plants are more rooted. Every other watering, she adds a water-soluble fertilizer. By August, she waters about twice a week, still fertilizing. Add water until it seeps from the drainage holes.

Find more ideas and inspiration on her website, and tour the Lawrence Garden Farm here.

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