After an unusual fall, winter, and spring in which many evergreens, both broad-leafed and needled, suffered burning and some die-back. My Q. myrsinifolia suffered only some minor leaf burn on 1 branch on its South side and some leaf loss at the very top of the crown, but it's now putting out new growth from the very top and everywhere else. So, no wood damage of any kind, and I've never had any wood damage in the past. My winter low temp was -17.8ºC(0ºF), but we were much colder than normal in terms of our daily high and low temps for much of the winter and spring. We also had an early warm period in late winter and very early spring(February into first week of March in which we had either no frost or only light frosts at night) which caused sap to rise in a lot of trees, but then we were well below normal for the rest of spring and a lot of those trees suffered damage from very hard freezes during this time. This did not happen to Q. mysinifolia, which typically is amongst the latest plants to put out new growth for me. It's a full 5 to 6 weeks later than most all other Oaks I grow in leafing out. I suspect this greatly helps it avoid such up and down spring weather damage here.
Fascinating information, thank you kman. Like you we had an extreme winter (not quite as cold as yours but almost) and many plants including established maples and mature (hardy) acacias have been damaged. I have also noticed that warmer-zone plants tend to leaf out later, which can avoid spring frost damage. Unfortunately a number of such plants did not survive or were heavily damaged this past winter. Such is life.
myrsinifolia sounds like a great bet, I will certainly be planting it this fall.
The plant I grow lost probably 75% of it's leaves this past Winter. It is completely re-leafed out now. Wondeing if the wind in Winter is trouble? Plant I grow is in a very exposed situation, near ocean, Z7.
I think the wind is part of your potential problem with yours losing its leaves, but I also think a lack of summer heat might be a problem as well. Everywhere in China I saw this Oak growing natively had hot humid summers and the places I saw it planted was the same. A few of the places I saw it planted had colder winters like me, but still relatively hot summers, so I think it needs quite a bit of heat to properly harden off and withstand cold windy winters better. In your case the ocean effect might also keep your plant from hardening off early enough in the fall to avoid leaf damage from the first real cold blasts of winter which can overwhelm the usually mild oceanic atmosphere near the coast temporarily. Although like you said, yours completely leafed out so it's more of a leaf retention problem rather than a wood hardiness problem for you and maybe some others in similar climates.
quercus myrsinifolia had been a long-term sought after dream for me. Eventually I got a large specimen from the UK this spring and planted it in my garden in the Czech Republic (this is in Europe, just in case ... :-)). Our zone is 6 and we regularly get lows of -20°C (-5F) every winter, sometimes more.
The other trouble is that our soil is quite compacted and clay which evergreen plants hate. For this reason, we have to put all evergreens up a bit above original soil level and still many freshly planted trees and shrubs turn yellowish the first winter until they get fully estbalished and get over excess moisture. But - q.myrsinifolia has not shown any winter damage yet (so far the lowerst we have had was -13,5°C in early December) - picture attached, while some other plants already show some sunburn (ceanothus, abelias).
This makes me believe that the leaves will not be so tender if they had enough heat to harden off in summer. Our summers can be quite hot while Sep/Oct weather gets colder and prevents the plants from making further growths unlike milder parts of Europe such as France, Netherlands or UK. If an evergreen plant does not show sunburn after the first hit of hard frost there is a reason to believe that it will be one zone hardier than the frost it has just survived.
The same applies for quercus rhysophylla "Maya" (loquat-leaf oak) which is in its first year in my garden. It is a gorgeous small tree with fantastic leaves. Today, after the second hit of immediate frost (yesterday we had 0°C at night, last night it was -11°C, and today it is sunny and -7°C), it shows no damage even on the new growths from August/September - picture attached. That is great news. Does anyone else grow this oak in zones 6 or 7?