You've heard me whine before about how I planted an Arbequina years ago that got very large. It died one year after a cold snap and resprouted from the base but eventually even those sprouts died. It's as if it could handle the freezing temps when it was 4 feet tall or less but once it got over 10 feet tall it was more tender. Another component to the story was that it was being crowded by a fast growing loquat tree and maybe the temps stayed milder under the canopy but once it reached outside of the shelter of those large leaves it faced real winter and couldn't take it.

I still have another un-named variety planted up against the brick wall of the foundation in another spot and it seems to handle winter just fine - but it has never bloomed or fruited.

I would love to grow olives! I have a loquat too, also zone 7, so perhaps we gardeners are all a rule-breaking lot. I doubt I'll get fruit from it, and now I'm thinking how wonderful it would be to get an olive... I will research the most hardy. Perhaps those listed as very hardy are not available to us? I have only seen arbequina, mission and more common ones listed!

Our current approach to this project is to go with a seed-grown wild olive - the species, not a named variety, which is generally considered hardy to USDA Zone 8a. We obtained a 1 ft tall seedling at the Raleigh 2016 Fall Swap (from Lorabell) and it is now about 4 ft tall in a 10 inch container:

Its form is still juvenile but it overwinters well as a houseplant (actually adding growth in the house) so we'll keep growing it like this until we get some backup cuttings. Older plants are supposed to be more hardy and planting them out close to a southern or western wall in well-drained soil (for instance on a pile of raised concrete) and with some protection below 15 F should help them survive cold.

More discussion on our favorite German gardening board, Exoten und Garten, about cold hardy olives: http://members3.boardhost.com/Exoten/msg/1549809995.html

For those who don't understand the language of Goethe and Schiller, they express continuing support for the hardiness of Morchione, Moufla, and Bianchera, as well as mention a new variety Elit-5, developed at the Botanical Garden in Plovdiv, Bulgaria and apparently available in Hungary. Specifically, Morchione is claimed to be the hardiest, with no leaf damage at -16 C (3.2 F) and Bianchera to resist long term frost with wind without leaf damage as well. Elit-5 is still being tested and may turn out even hardier than Morchione. They also recommend to treat olives like succulents by planting them in well drained dry ground.

Maybe Tony Avent should head an expedition to Eastern Europe to bring back a few cold hardy Mediterranean plants?

Has anyone tried to graft european olives to the american olive (Osmanthus Americanus)?

It sounds like its pretty well suited to the climate here in 7b (raleigh nc), but I can't find very much research on it in regards to grafting or even its fruit. I'm considering ordering 5 to try to get at least one male/female meaning i should have some extras.

Which O. europaea variety did you use as graft?

I used Arbequina. If it survives a full year, I'd like to try some other varieties as well.

Keep us updated, joshua! This is a VERY interesting experiment.

If nothing else, grafting onto a native plant should give it better ability to cope with the soils and heavy summer rainfall of the SE US - meaning it will store up more carbohydrates for winter, and have more cold resistance although probably not changing the absolute hardiness much. Yellow elepidote rhododendrons are mostly derived from the incredibly root rot sensitive species R. wardii. 'Nancy Evans', one of the best yellow cultivars, sulked here as an own-root plant. Because it could barely survive a summer, it would defoliate in winter. Even worse with 'Yellow Petticoats' that could not make _through_ a summer. As grafted plants, they grow very vigorously and seem fully winter hardy.

CasaLester - I've never spotted cultivars like the ones you mentioned, 'Morchione' et al, for sale in the US. Any luck locating them? Have seen this? https://calag.ucanr.edu//Archive/?article=ca.v047n01pS1

The grafts are still alive for now. I'll see how they do over wintering.

David, very interesting article. It seems that there are so many olive varieties that the ones preferred in the US don't overlap with those more popular in Europe. But many varieties listed as 'resistant' in the UCANR article do appear in the VariedadesDeOlivo list, often with high cold resistance (mostly 4, haven't seen any 5). There are many minor spelling differences that show how far these catalogs have diverged.

That's why we joked earlier that Tony Avent should organize an expedition to Europe in search of more cold hardy Mediterranean plants. We are inclined to trust our German and Eastern European friends to be more systematic in finding the most resistant varieties since they have no optimal options like California or Florida.

From what I understand, it's very expensive to bring back plants or cuttings legally. If that isn't the case, i go to the eu yearly

Are active experiment?

Are you still doing this experiment?