Well, my citruses have survived the arctic blast that went down to 20 deg F. All in all it was a whole continuous week of freezing early mornings ranging from 20 to 27 deg F.

I have Key lime, Bears Lime and Kaffir Lime on my 50-n-1 tree and not a single leaf was damaged and all of these should give out at 27 deg F and below. Not a single leaf drop so far especially the Kaffir from EZ, not a single fruit rotten (except the ultra-ripe unharvested ones).

But that was not a valid test of cold hardiness due to my interventions. Nonetheless, I have proven it possible to combat rare cold events encountered by inground citruses in Northern California without the use of complete enclosures like greenhouses, as long as you are a dedicated and resourceful hobbyist. Of course there's still price to pay as what happened to my other neglected fruit trees and fish pond during the coldest days.

I would have placed many thermocouple sensors on the spots on the tree where these cold sensitive types are located and have recorded the actual temps due to my interventions. Next project would be to source out some thermocouple thermometers just in case another event like this one would come within the next 10 to 20 years.

Same here. I have similar experience. The noticeable effect only is in my key lime and guava tree and bananas- lost all of its leaves. The pomelo and joe's clemenule were in the middle of sprouting new leaves and flowers were affected too. Had I cvered them with bedsheets I could have saved the new leaves but I covered them too late. But not all the young leaves and flowers were lost. Some stayed green and unaffected.My other citrus with plain cover on top and those that had been with me for several years were not affected at all. Their fruit are still intact but I picked maybe half of them although they were not ripe and I am just using them as juice right now.

JoeReal & bencelest, your problems are enviable - at least from my perspective! Drive north up I5 900 miles and you will hit my home! We have a cool, mild winter with 0 to 3 cold spells per season. Thats leaves 95 percent of the time citrus will survive without protection. Thriving is a different story - a work in progress for me to figure out which varieties will do the best with the least amount of intervention. Lack of prolonged summer heat is probably my biggest hurdle. Long term survival will no doubt be challenging. I think we all do what we have to grow citrus - wherever we live. Being rescourceful is the key - if there is a will then there is away. All my citrus survived the week long cold spell too - for the same week (we had a low of 18 and a highs of 34) . My Meyers held their fruit and blossoms.

I have an Aunt in Surrey, BC (and other relatives in east side of Canada). One of these days I will tell her to plant her potted Calamondins outside.

Maybe you can try planting Yuzu, Sudachi Hybrid, other more palatable types of Flying Dragon, from seeds, the only thing legal to use in Canada if you can't find the cultivars. I've thrown away several hundred seeds of Yuzu when I made Yuzucal wine (combination Yuzu and Calamondin). The last of my one remaining Yuzu I've sent to Martha (requested by Eyekr), so no more seed sources from me. Perhaps next year the sudachi will bloom and will save some seeds.

Yes you are right that while Surrey BC may be survivable for some citruses, nice growth would be another matter.

Joe

Joereal, I have jumped through some pretty big hoops to import plants (citrus and avocados) into Canada. There are some available locally but not alot of the non mainstream hardy citrus. Monrovia stock can be special ordered if you find a nursery you can work with. Its a good thing that us citruholics are a friendly bunch - I have had several offers to help me out in getting this collection going. As well as the offer of shipping up fruit! I have (just) read about the sudachi...any ideas of its cold tolerance? I am working on getting some Kishus as well - we had allot of them arrive from China in the last 2 months here in the Vancouver area (at least thats the closest I can get to Idenification of the fruit) Next time you visit your aunt you can bring up some of that citrus wine!
Cheers, Greg

The original sudachi is known to survive single digit deg F. The cold hardiness, IIRC, is 10 deg F, so that is about -12.2 deg C.

And sudachi sauces are very pricey!