Thuja plicata is a species native to a large portion of the PNW. 'Grovepli' (aka Spring Grove) is a selected cultivar of that species. Named forms/cultivars are seldom found occurring naturally in any quantity as they are typically vegetatively propagated to maintain specific characteristics.

There are many PNW natives that are sold as specific cultivars, including red osier dogwoods, flowering currants, vine maples, evergreen huckleberries and of course, western red cedars/Thuja plicata. Most folks use these interchangeably with the true native species.

If you are trying to do authentic native plantings you will avoid vegetatively propagated horticultural clones such as this. Purists will also want to avoid stock grown from collections made far away in the locally occurring species native range, such as western redcedar in Montana - the concern being crossing of the local races with those from elsewhere.

Thanks so much for your response. Any idea if local nurseries in Washington carry them? I called a few nurseries in Bellingham, but they don't stock these.

Selected back East, making me wonder if it was actually pure western redcedar and not a hybrid of it such as 'Green Giant' - or a form of a completely different species, namely Thuja occidentalis. But eventually I saw stock here so-labeled, and that it looked like western redcedar - more so than 'Green Giant'. So I guess that means it has been on the garden center market here. But I do not see why one would buy this (for use in this region) instead of any other named selection, or even just unselected seedlings, if native/naturalistic plantings were intended (in the latter case).

Yes, why do you want this certain variety?
Is it something special?
I've never heard of it,....,
but that's not a rare thing.
Mike

Yes, why do you want this certain variety?
Is it something special?
I've never heard of it,....,
but that's not a rare thing.
Mike

Ditto - why do you want this particular cultivar?

If you want to do a native landscape then you want to avoid nursery cultivars. You'd want to use plants that were either propagated from seed or that were salvaged by a native plant salvage organization, for genetic diversity. By definition, nursery cultivars lack genetic diversity.

If you want to do a landscape that includes native plants, well, I don't see any reason to want this particular one. An admittedly very brief google search for this cultivar says it's cold hardy to Midwestern winters, which we don't need here, and that it's a good deer-proof hedge, which is redundant - pretty much any red-cedar will be equally deer-browse proof. No reason I see, in red-cedar's native range, to use this cultivar, as those are its two selling points and they're irrelevant here.

Perhaps we are over-focusing on the native species part of the OP's question :-) Sure, there are many purists that want only native plantings and some restoration and/or wetland situations where only natives are permitted but just as many other gardeners select cultivated 'natives' for their typically greater ornamental value as well as their attraction to wildlife and ability to do well in our climate.

This particular selection of WRC has a quite narrow, more columnar profile than the native and a significantly shorter height. I'm not sure any more justification is required - specific attributes that fit the gardener's specific needs are perfectly acceptable reasons why they select named WRC's like 'Excelsa', 'Virescens', 'Can Can', 'Zebrina', etc., rather than the straight species. It is always a matter of personal choice.

I wouldn't count on the more narrow growth and shorter height being universal or even accurate. Crown structure of cypress family conifers varies markedly with district even right here in the native area; cultivar was named in a completely different part of the country. And may not have been observed long enough back there to know ultimate height, let alone how tall it might grow out here.

Commercial sources chronically underplay growth potential of tree and shrub cultivars. Shade tree selections so often grow only 20'-30' tall, even though the parent species grows triple that height, upright conifers are somehow always comparatively slender and never get "too tall", therefore perfect for modern small planting situations and so on.