The Sill + Terrain: Planting a Window Box

This month, we're teaming up with The Sill to focus on indoor gardens. Always seeking new ways to bridge the gap between plants and people, The Sill inspires us with creative ideas for indoor, windowsill, and near patio gardening. Stay tuned throughout April as The Sill shares more of their abundant knowledge; below, check out some tips for cultivating a beautiful window box.

Indoor window boxes are a go-to for both frustrated urban gardeners and nervous beginners. If you lack the time, energy, spare space, or green thumb to maintain a large garden, you can still enjoy greenery in small yet striking ways with window boxes. Available in an endless amount of choices of color, texture, and size, you are sure to find one that is a perfect fit for you and your space. Check out three of our favorite designs below. 

Herb Window Box
Herbs are a popular choice for window boxes because of their usefulness – nothing beats having fresh herbs on hand. We chose basil, which prefers full sun, but there’s a multitude of herbs out there that can thrive in a shadier sill. Make sure to choose the right herb based on your light. 

If you plan to plant more than one herb in your box, make sure to combine plants that need the same amount of light and water. Planting in a plastic liner instead of directly into the box makes changing plantings easy. Seed packets are definitely the most economical way to go – but small plants ready for transplanting into your box will be ready to harvest sooner. 

Top 5 Light Shade Picks: Mint, Chamomile, Thyme, Parsley, Cilantro
Top 5 Full Sun Picks: Basil, Lavender, Oregano, Rosemary, Chives  

Sedum Window Box 
This window box is a fresh and modern take on the conventional. Small in size but big in impact, we choose colorful ceramic planters to complement the wild mix of sedum. If you have a brown thumb or busy schedule, this is the box for you. Sedum’s fleshy, succulent leaves mean you can skip a watering or two. Just make sure to find it a sunny spot to call home. We’d recommend an eastern or southern-facing sill that receives direct light. As an added bonus, many species of sedum flower in the late summer or early fall. 

Top 5 Sedum Picks: Sedum cauticola, Sedum ‘Ogon’, Sedum spathulifolium, Sedum ‘Angelina’, Sedum ‘Blue Spruce’ 

Leafy Low-Light Window Box 
We created these window boxes for a start-up’s Union Square office. Although the windows are large in size they do not get direct light for more than a couple hours a day. Because of this, we choose a variety of moderate to low-light plants including areca palms, pothos, philodendrons, ivy, and dracaenas, creating an interesting contrast of height and hue. 

Top 5 Low Light Picks: Philodendron, Pothos, Snake Plant, Dracaena, ZZ Plant 

Four Tips for All Window Boxes 
1. Pick the right potting soil
Choose a good quality, fast draining soil. For small potted plants, including smaller window boxes, we recommend Brooklyn Blend potting soil. A lightweight potting mix, it makes moving around window boxes a bit easier. 

2. Create drainage 
It is important to have a box with drainage. If your window box does not have drainage holes, layer the bottom with stone or gravel to create drainage. We like to use a mix of lava rocks and charcoal. 

3. Leave room for growth   
Don’t cram plants in too tightly. Leave room for roots to breath, and plants to grow. 

4. Prune and snip  
Don’t be afraid to clip and cut. Regular pruning keeps plants in a restricted space healthy and happy. Herbs especially benefit from constant harvesting. Pruned plants grow back more thickly and compactly, too. 

Follow our partnered Window Gardens Pinterest board for more inspiration!