Hello,
i'm guessing your climate is too cold for olives. I grow olive trees here in Pennsylvania. Olives are evergreen, so they do require enough light even in winter. So if you are to grow it indoor, provide a spot that is a bit cool and well lit. I grow mine in the greenhouse, temperatures in winter drop to 40 F, which is beneficial for olives, especially if you want it to flower. In summer time, bring the tree out to full sun, It loves the sun.
As far as propagation, they can be grown from cuttings. In the middle east they take cuttings with a heel of the tree. Basically, the cutting can be two year old growth with 1 year old growth.
Hope this helps. Good luck growing it.
Bass

bonsaist,
Thanks for the info. I do have another question, will it matter what stage the tree is in (fruiting or not) when taking a cutting? Also, from what I know ( not a lot ) the light cycle will determine if the tree is in a vegetative state or fruiting. Is this applicable to olive trees? Again thanks for your help!

I would say the best time for taking cuttings is late winter.

This site says June/July:

Carla in Sac

Here is a link that might be useful: Prop Olives

Bass:

I know you go to considerable lengths to grow exotic fruiting trees and plants, but in the case of olives, do you ever actually see fruit on the trees after all the inning and outing, and, if so, is it of any culinary value?

Many of the producing olive trees I have seen in Europe are big, gnarly old things that look to be more than 100 years old. We had a fairly large producing age tree in our backyard in Lisbon, Portugal, where winter temps rarely fell below 35 F. But the olives were small, mostly seed, and we never found a use for them. I suppose they could have been pressed for oil, but we weren't set up for that and olive oil was cheap in Portugal at the time.

I guess what I am driving at is: Is it really worthwhile to try to grow an olive tree in a northern climate, except as a pet? California is a different story, as it is for many fruits, and an olive tree could, at a minimum, be an attractive and drought resistant addition to a landscape.

Don Yellman, Great Falls, VA

Don,
I do get a few Olives from my several olive trees, but that's not the purpose that I'm growing them. I grow them for nostalgia sake. I think I have like 8 olive trees.
I enjoy eating olives, but as you probably already know you can just pick it off the tree and eat it, you need to cure it.
I have to admit that I've taking Olive cuttings at different time of year in growing season and they still took for me. Some cuttings were 2"-3" thick with a small buds.

Bass

Hi, I have an olive tree that I grow in a pot on my balcony in New York City. I’m wondering what to do with it in the winter. Many place online say that I shouldn’t bring it indoors. Should I keep it outside and perhaps get one of those mini green houses to protect it from the cold? Would that even suffice? Mini Walk-in Greenhouse 3 Tier 6 Shelves with PE Cover and Roll-Up Zipper Door, Waterproof Cloche Portable Greenhouse Tent-55.9L x 28.3W x 75.59H Inches, Grow Seeds & Seedlings, Tend Potted Plants https://www.amazon.com/dp/B08251Q467/ref=cm_sw_r_cp_api_i_.dANFbF5FXM2Q?_encoding=UTF8&psc=1

Hi, I bought an olive tree to keep indoors but I have underfloor heating, how can I best look after it especially with winter and the underfloor heating being on most of the day ?