The olive tree is truly eternal

In the midst of winter it sometimes helps to have indoor plants that remind us that season in and season out, the cold will eventually give way to the sun of summer.

Thanks to dwarfing techniques, our houseplants can include small trees, and what better tree than your very own indoor olive tree? Ever since that dove returned to Noah's Ark with an olive branch, olive leaves symbolize peace and hope.

Olives fresh from the tree are virtually inedible, so they are treated with lye and pickled in brine. But olive oil can be pressed from the newly picked fruits without any additional processing. Part of the healthy Mediterranean diet, olive oil has lots of natural antioxidants and healthy monounsaturated fats, which help to lower blood pressure, forestall coronary heart disease, lower cholesterol, and even build up the immune system, to name but a few benefits.

Because they are tolerant of poor soil and drought, and can even survive a light winter chill, olive trees do well in containers.

The trees, even when not in fruit, are beautiful with traditional silvery foliage. After about four years, your olive trees may begin to bloom with clusters of small, white flowers with a delicate feathery shape and a pleasant fragrance.

There are two olive tree varieties suitable for indoor pots, Cailletier and Arbequina.

The Cailletier olive is known as the Nicoise Olive, because it is favored in Salad Nicoise. It's a French variety that doesn't need a pollinator to produce its small, black olives.

Even though Cailletier olive is self-fertile, you will have bigger crops planting it alongside an Arbequina olive tree. The Arbequina olive is also self-fertile and comes from northern Spain. This variety is known to bloom and set fruit at an early age, sometimes when just a foot tall.

To get your olive trees to bloom, be sure they get as much sun as possible, along with cooler nights down to 30-45°F during the winter. Olive trees grow in low humidity, so they do well in drier air found in most homes.

Soil in pots dries up quicker than in the garden, so you need to water potted plants on a regular basis. Let the top inch of soil dry out before watering again. Olive trees thrive in drought, so water no more than every two weeks - less in the winter. 

Olive trees prefer soil that drains easily; use soil intended for cactus. Be sure your pots have several drainage holes so water doesn't stay near the roots. Even though olive trees are slow growing, be sure the pot is several inches larger than the root ball. A larger pot also means you won't have to repot the tree for several years.

You can prune or cut back your potted olive tree at the end of winter before growth starts in the spring. Your potted olive trees will grow best with light pruning once a year rather than cutting back too much every two or three years. Prune all branches that point downward, and keep lateral branches and those growing upright. Keep the center of the tree open for better air circulation.

Fertilize your potted olive trees during spring although, they seem to do fine without any additional nutrients.

Plant an olive tree (Olea europaea) in a large pot and you will have a houseplant that may very well outlast the house, as olive trees can easily live between 300 and 600 years. Indeed, the biblical Garden of Gethsemane, whose name means “olive press” in Hebrew, has olive trees that still bear fruit even though the trees are over 2,000 years old. Like the peace that it symbolizes, the olive tree is truly eternal.