European Olive Tree
Olive trees grown indoors live eight to nine years, a much shorter lifespan than landscape Olive trees, which are known for their longevity. The best you can do for the tree is to move it outdoors during the summer months because even the best indoor conditions can't match preferred conditions outdoors.
Aside from those caveats, slow-growing olive trees are easy to care for indoors.
The ability to grow olive trees indoors hinges on the amount of available sunlight. Native to the Mediterranean basin, olive trees receive lots of sun exposure. Providing direct sunlight is key, so if you have a suitable spot, like a south-facing window, you should be able to grow an olive tree indoors.
Olive trees require at least six hours of direct sunlight per day. A large south-facing window is the only indoor location that can provide the necessary sun exposure. Make sure the leaves do not touch the window glass, which can cause them to become scorched.1 To ensure equal light exposure on all sides, turn the pot 90 degrees every week.
If your home does not offer sufficient natural light, you can also set up a grow light. Leave it on for at least six hours every day, increasing this to eight hours if you aren’t able to move the tree outdoors in summer.
Full-spectrum light is best, as it comes the closest to sunlight at midday, in a combination of red and blue lights for overall healthy plant growth. LED lights are the most energy-efficient and long-lasting solution.
In their native Mediterranean climate, summers are hot and dry with low humidity and winters are cool and moist. For an olive tree grown indoors, a room temperature between 65 and 80 degrees Fahrenheit is best. Because it can withstand dry air, keeping it in a heated room of up to 40% relative humidity is fine. However, the plant should be kept away from heat vents and radiators to prevent drying out.
The soil of a potted olive tree should never fully dry out, but be careful not to overwater. When the soil is dry to a depth of 1 inch (stick your index finger in the soil to check), water slowly and deeply until the soil is soaked and water trickles out of the drainage holes.
In the winter, when the tree is dormant, it will require less water but a dry top layer of soil indicates the tree should be watered.
Olive trees in the landscape don’t need much fertilizer. Potted olives have slightly higher needs as fertilizer gets washed out of the potting soil, but they are still light feeders. Starting in the early spring and throughout the summer, feed the tree once a month with a time released fertilizer. As for the amount, follow the label instructions, as the nutrient content of fertilizers varies. Stop fertilizing the tree in the fall and don’t fertilize it during its dormancy period in the winter.
