Boxwoods are a classic choice for balcony decor all summer long. Technically, they can stay out there through the winter, too, since these evergreens are officially rated as hardy. However, seasoned gardeners know that container plants take a much harder hit from the frost than those planted in the ground. But don’t worry—with a little prep work, your boxwood will come through just fine.
Insulating the Root Zone
The green part of your plant—everything you see above the soil—still needs light and air during the winter. The real “weak spot” is the root system. If temperatures drop well below freezing for a long stretch, the soil in a pot will eventually freeze solid because the frost attacks it from all sides. To prevent this, you need to bundle it up:
- Wrap the pot in garden fleece, burlap, or bubble wrap.
- Pro tip: Place the pot inside a larger container and fill the gap with mulch for extra insulation.
- Elevate the pot by placing it on wooden slats or a piece of Styrofoam.
- Make sure you leave an opening at the top for watering.
- Don’t block the drainage holes at the bottom!
Quick Tip:
Give your boxwood a little boost by fertilizing it with potassium in late August. This helps the new shoots mature and harden off, which is a great way to prevent frost damage later on.
Avoid Sunny and Windy Spots
We usually worry about sunburn and dried-out branches in the summer, but it can happen in the winter, too! Windy and sunny locations are the biggest culprits. Your best bet is to move your boxwood closer to the house wall, where it’s shielded from the elements. If you can’t move it, try using a shading net, a patio umbrella, or coconut mats to protect the plant on those surprisingly warm, sunny winter days.
Don’t Forget to Water!
Since boxwoods are evergreen, they continue to lose moisture through their leaves even in the winter. This means they still need a drink now and then. However, since the plant isn’t actively growing, it won’t be as thirsty as usual. Dial back the amount of water you give it; otherwise, you risk waterlogging the soil and causing root rot.
Alternative Wintering Options
Leaving your plant on the balcony isn’t your only option for wintering. If you have a garden, you can actually “heel in” the boxwood by burying it (pot and all) in the ground temporarily. The earth provides much better insulation for the roots than the open air. You can also bring the boxwood indoors to a bright, frost-free spot until spring. This is especially recommended for young plants or more exotic varieties that aren’t quite as cold-hardy as the standard types.
