Here's the whole argument for these fall window boxes: ornamental kale lasts far longer than mums.
Mums give you four to six weeks. Ornamental kale looks better as the nights get colder, the colors deepen after a few cool nights, and it often keeps going through light frosts well into November or even December. Pair it with dark heuchera and trailing ivy and you have a window box that looks good for the whole season.
The planting plan
For a standard 36-inch window box:
- Center: two or three ornamental kale plants in purple and cream.
- Either side: a dark burgundy heuchera.
- Tucked between: two small bronze mums for extra color early in the season.
- Front edge: variegated ivy trailing over.
That's about eight to ten plants for a full, lush box.
Why kale works so well
Ornamental kale and cabbage are grown for their leaves, not flowers, so there's nothing to fade. They're also frost-tolerant; the colors actually intensify once nighttime temperatures drop below about 50°F. Most varieties handle light frosts well.
Heuchera
Heuchera, also called coral bells, has beautiful foliage in burgundy, lime, caramel and near-black. Dark burgundy varieties look especially good with purple kale. Heuchera is a perennial, so you can plant it in the garden when you empty the box.
Trailing ivy
Variegated ivy softens the front of the box and trails down the wall. It's hardy and often survives winter. Creeping Jenny is a golden alternative.
Box color
A black or dark painted wooden box makes the plants stand out. White boxes look crisp. Natural wood looks rustic. Match or contrast with your shutters or trim.
Planting tips
- Use fresh potting mix, not garden soil.
- Plant close together. Fall plants don't grow much, so plant them almost touching for a full look.
- Water well after planting and whenever the top inch is dry.
- Make sure the box drains.
Adding small pumpkins
A couple of mini pumpkins or gourds tucked into the box between plants add a seasonal touch for October. Remove them if they start to soften.
After fall
When the mums finish, remove them and fill the gaps with evergreen cuttings, pinecones and berried branches. The kale and heuchera can stay into winter in many areas.
Other plants that work in fall window boxes
- Pansies and violas: cool-season flowers that bloom through fall and often return in spring.
- Dusty miller: silver leaves that glow against dark boxes.
- Ornamental peppers: small, colorful and upright.
- Carex or small grasses: for texture and movement.
- Wintergreen or small evergreens: for a box that carries into winter.
Mix one or two of these with the kale and heuchera if you want more variety. Stick to a palette of purple, burgundy, cream and green so the box looks calm.
Watering fall window boxes
Cooler weather means less evaporation, but window boxes still dry out faster than garden beds because of the small soil volume and wind. Check with your finger every few days and water when the top inch is dry. Stop watering when the soil freezes.
Window boxes for shade
If your window gets little sun, heuchera and ivy do well in shade. Ornamental kale prefers sun but tolerates some shade. Skip mums, which need sun, and add more heuchera.
What it costs
- Two to three ornamental kale: $10 to $25.
- Two heuchera: $15 to $30.
- Two mums: $10 to $20.
- Ivy: $8 to $15.
- Potting mix: $10 to $15.
Mistakes to avoid
- Planting too sparsely. Pack them in.
- Using garden soil.
- Mums only. They fade fast.
- Forgetting to water. Window boxes dry out quickly.
Fall window boxes FAQ
What do you put in fall window boxes?
Ornamental kale, heuchera, mums, ornamental grasses and trailing ivy or creeping Jenny.
What fall plants last the longest in window boxes?
Ornamental kale and heuchera. Both last well past the first frosts.
Can ornamental kale survive frost?
Most varieties tolerate light frosts, and the colors deepen in cool weather.
What's good for a shady fall window box?
Heuchera, ivy and ferns.
