Looking for Sitka alder - Alnus viridis close to Vancouver (city) in order to minimize travel. I am planning to harvest some seeds and perhaps take some cuttings and see if I can get any root growth before the leaves drop, or see if they resume in the spring. Any suggestions for close by specimens?
I'm not familiar with this species, but I see that there are many locations for Sitka Alder (Alnus alnobetula sinuata) shown in iNaturalist, especially in Cypress Park.
One of exceptional size - presumably the same specimen as #29 on the page linked to below - used to be on a lawn at UBC. Perhaps it is still there and even in good condition. campus_trees_2.pdf (ubc.ca)
Just to clarify names: Green Alder: Alnus alnobetula (with nominate subsp. alnobetula in central Europe), formerly Alnus viridis Sitka Alder: Alnus alnobetula subsp. sinuata, formerly Alnus viridis subsp. sinuata Make sure you get the right subspecies!
I don't know of any close to Vancouver. I happened to get some seedlings this summer from Woodmere Nursery in Telkwa. They grow trees for the Ministry of Forests. (They also have a site in northeastern Alberta, where the trees are used on old mine sites to reclaim the land.) My first choice was actually Speckled Alder (AKA Gray Alder); I hadn't heard of Sitka Alder before. In any case, that is pretty far away, so probably not much help to you. I am curious: why Sitka Alder? That is a tree for colder climates. Same for Gray Alder and Green Alder. Why do you want to grow it in the Vancouver area? There are so many other options. I go up north every summer; if you can wait a year, I can bring some down with me next July.
Anywhere up in the mountains around Vancouver should have it? It is mapped as native there. Look in avalanche chutes, that's its usual habitat - the avalanches get rid of larger trees that would otherwise out-compete it. Tip: collect the seed before any snow accumulations make this a risky task!! Can't answer for Darb, but personally, I think it (Green Alder subsp. alnobetula anyway) is a more attractive plant than Grey Alder, and it's also a shrub, so better where you don't have space for a 10-15 metre tree. While it usually occurs in colder areas naturally, it doesn't have any problems growing in warmer sites, as long as it isn't crowded out by more vigorous trees.
As I posted on Sep. 19 there is a history of an unusually large - yet correctly identified - planted example being on the UBC campus. In addition scattered spontaneous occurrences are known from other lowland locations near salt water such as Seattle, Tacoma and Vashon Island. (Also all correctly identified, and not misinterpreted red alders). With the latter for a time having a specimen I measured that became the United States National Champion. (For a time because the property occupant unwittingly destroyed it later). The Vashon tree was much smaller than the amazing UBC one but unlike it present within the area of coverage for the American Forests champion tree listing system. Anyway I see at least one or two BC collection sites not in the mountains popping up on the first page of results here. In addition to the UBC planting, which even appears on a map that I linked to above: CPNWH Search Results (pnwherbaria.org)