If you’re dreaming of turning your backyard into a Mediterranean oasis, an olive tree is probably at the top of your wishlist. Most of us here in the States tend to keep them in pots so we can wheel them inside when it gets chilly, since they usually only survive year-round in the ground in places with super mild winters (think coastal California or parts of the Southwest). However, if you’re determined to plant one in a cooler climate, you can actually make it work—but you’re going to need a little help from a heater.
A Serious Commitment
Unless you live in a region where winters are exceptionally mild, planting an olive tree directly in the ground is a bit of a project. While these trees are pretty tough and can handle a light, short-term frost without breaking a sweat, a long cold snap will kill them off pretty quickly. Protecting them through a real winter is definitely “advanced gardening,” but it’s doable if you’re prepared for the work.
Protecting the Trunk and the Roots
When it comes to winterizing your olive tree, you have to think about two things: the roots underground and the trunk above it. Simply wrapping the trunk in garden fleece or old blankets might cut it if the temperature just dips slightly below freezing for a night. But if you’re facing a deep freeze that lasts for days, you’re going to need some electric heat to keep the tree alive.
A Total Balancing Act
Installing a heating system in the soil is a big job, and running it requires some finesse. You only want to flip the switch when a hard frost is actually hitting. If you overdo it and the soil temperature climbs above 41°F (5°C), the tree gets confused and enters its growth phase. If the tree starts growing in the middle of winter, it often ends up drying out and dying.
In addition to keeping the roots cozy, you’ve got to protect the trunk. A classic pro-tip? Use heavy-duty outdoor Christmas lights (the old-school ones that get a little warm, not LEDs). Wrap those around the trunk and then wrap one of these materials over the top to trap the heat:
- Garden fleece
- Burlap
- Old blankets
