Hi there... I am wondering if there are any species of live oak (Quercus virginiana, Quercus ilex, Quercus suber) that are hardy in Vancouver... and if Vancouver can meet these species heat requirements.. the Sunset garden website indicates these should be hardy here... but I am not sure. These are beautiful trees and would look great planted here if it is possible... Anyways, let me know your opinions Thanks
Holm Oak (Q. ilex) should certainly be hardy, and doesn't have a high summer heat requirement (it grows very well in the very chilly summers of the coast of NE England). The other two do need more summer heat. Some of the California oaks would also be worth a try.
All three are grown in Seattle. But your best bet might be Q. chrysolepis. Another to try would be Q. hypoleucoides.
That's great.... I think these all are such beautiful trees... and I will definitely keep a look out for them. I love all types of broadleaved evergreens and these trees with their imposing size and form... I think makes them special.
If you want imposing size, the largest hardy broadleaf evergreen is probably Nothofagus dombeyi. Specimens in Britain up to 35m tall, compared to 28m for the tallest Holm Oak. The only taller broadleaf evergreens in Britain are some Eucalyptus in very mild areas, would be of dubious hardiness in Vancouver.
Interesting.. so Nothfagus Dombeyi is bigger than most oaks... I've seen pictures of Nothofagus and they look beautiful as well. There are a couple of species of Eucalyptus which are hardy in Vancouver and I see them planted around the city every so often.. mostly E. gunnii and E. pauciflora. I'm not sure how they compare in size to either Nothofagus species or Oaks in terms of size when they are full grown. Also, Magnolia grandiflora is around here as well but I don't think they get as big as the other trees....
Yep, big, and nice. There's also the big advantage that the champion N. dombeyi is not in one of the warmest parts of Britain (Muncaster Castle, Cumbria, in NW England) so it gets big even with cooler conditions. There's a 37m E. gunnii in Ireland, and one 29m in Britain, but I suspect it wouldn't get so large with you as Vancouver is a bit colder in winter, and gums seem to be particularly responsive to warmer conditions. E. pauciflora is a smaller species, to max. 26m but usually quite a lot less than that (15m would normally be large). The larger gums are all less hardy, over here confined to the mildest parts of Ireland (zone 9b, even 10a): E. globulus to 44m, E. viminalis to 43m, E. bridgesiana 39m, E. delegatensis 38m (and all these will of course get even larger than this in Australia, New Zealand, Calif., etc.). Biggest Magnolia grandiflora in Britain is a lowly 13m . . . it definitely needs a lot more summer heat than it gets here!
For records measured closer to home see Van Pelt, Champion Trees of Washington State and Jacobson, Trees of Seattle - Second Edition. The former dates from 1996 and is out of print, the latter from 2006 - order it directly from the author to help support his work. Southern beeches have shown a tendency to blow over in Seattle. Gums often grow tall for some years only to freeze back in a hard winter. Hardiness of gums varies rather widely even among related seedlings. Some species and some individuals are more hardy than others. Getting back to the oaks, a Quercus chrysolepis at Big Lake, in the hills near Mt Vernon, WA was 9'7" around during 1990. Another, on the same site had an average crown spread of 60' the same year. (See Van Pelt for full listing, including address - the trees are right on the road, in front of a conspicuous church building). I suspect a Q. ilex in the same location would freeze out at some point.
That would surprise me. I've never heard of freezing problems with it in Britain; Bean comments "In very severe winters it is occasionally denuded of foliage", nothing worse than that. There are even some (smallish) ones in zone 7 Denmark, and parts of its native range in N Greece and France extend just into zone 7 areas. According to German wikipedia "In Deutschland ist sie nur in den allermildesten Lagen (etwa im Rheingraben, im Bodenseeraum oder im Weser-Ems-Gebiet) einigermaßen winterhart" [In Germany it is only in the mildest areas (e.g. in the Rhine Graben, in the Lake Constance area or in the Weser-Ems-Gebiet) reasonably hardy] - that would also place it as hardy just into zone 7. Swedish wikipedia states tolerant of short spells down to -20 to -25°C, which I have no reasons to doubt. I'd say probably about the same hardiness as Sequoia sempervirens or Araucaria araucana, or perhaps just slightly hardier.
Well... if it is hardy into zone 7.. Q. ilex should be no problem here.... This past winter was a brutal one for us as we had an overnight low of -15 which pushed us into zone 7b territory (although most years it's mostly 8a or 8b down by the water).. I've seen quite a few tender plants looking a bit ragged but I can already see signs of new growth so I think most will survive. Live Oaks from what I read seem to be incredibly resilient trees even if a lot of their foliage dies off in a harsh winter, new growth will start in the spring. This is what happens in the northern end of its range even in places like Ohio and Southern Indiana.
Q. ilex rare here, with few large ones. I know of no large Q. virginiana here. Neither are as striking as Q. hypoleucoides.
I guess Q. ilex and Q. virginiana don't get too big here because of lack of summer heat that they experience in their native environments.... Other than size, would you say there is anything else striking about Q. hypoleucoides?
It's not particularly large-growing. The foliage is the attraction. It also produces a more open and slender crown than many evergreen oaks. With that and its silvery coloring it's kind of a "quercalyptus". Doubtless you can find pictures and descriptions elsewhere on the internet. Other evergreen oaks from the southwest US and Mexico also produce more interesting leaves than usual, like those of various wild rhododendrons from Asia. There are a few large Q. ilex here. Just not the numbers that would indicate it was a successful garden tree. Many might find it heavy and somber, as did Alan Mitchell.
True for Q. virginiana, but not Q. ilex; that (like surprisingly many Mediterranean plants) isn't bothered at all by cool summers. One of the largest in Britain is on the NE England coast, with a July mean temperature of under 15°C.
Well that is comforting.... I always feel that the lack of summer heat always seems to be a big obstacle in growing many plants which should be considered hardy for the area.... not just some species of live oaks like Q. virginiana and Q. suber (I suspect this species of oak also requires a lot of summer heat) but other species from the SE USA like Sabal Minor and R. Hystrix which should be hardy here but are virtually never seen probably due to little summer heat we get.
Yep, Q. suber does need more heat; unlike Q. ilex, it is ± confined to SW England and southern Ireland in cultivation over here.
