So recently I acquired two white pine cultivars. One is a Catherine Elizabeth which is a dwarf cultivar, and an Arakawa which is a cork bark variety. The question is should they be treated like long needle single flush or short needle single flush? I’d imagine the dwarf cultivars would be a short needle. Arakawa long? Any help would be appreciated. I’m PA zone 6A.
Was able to get this answer from another forum. Hope it’s helpful to others, and might shine light on the subject for others that are curious.
“Both ‘Catherine Elizabeth’ and ‘Arakawa’ are Pinus parviflora - Japanese white pines. They are treated like Japanese white pines, a category that pre-existed or is the grandfather of the whole somewhat arbitrary category of Single Flush pines. There is a huge volume of literature, books, and web pages devoted strictly to Japanese white pines. Don’t confuse yourself by trying to fit JWP into any categories other than Japanese White Pine. It is its own thing, and its care and techniques are very well documented, second best documented pine. compared to any other pine, only the Japanese Black Pine, might have more articles and books written about it.
Techniques for all other single flush pines were based on techniques for Japanese white pines. So look up and only study Japanese white pine techniques when looking for care guidelines for ‘Catherine Elizabeth’ and ‘Arakawa’. Don’t confuse yourself by including anything that is not specifically Japanese white pine related.
‘Arakawa’ is a dwarf to near normal size growing JWP. Its ultimate size in the ground is maybe 10 to 15 feet in 20 years. Its needles are average, 3 to 4 inches long, and straight, with minimal twisting. Needles are a medium to dark green, with some “blue” from the lines of stoma on the undersides of the needles. It is not particularly blue, but it is definitely not yellow if healthy. Some JWP can be yellowish green. ‘Arakawa’ is a nice medium dark green. It develops a warty bark. It is not ridged like some Japanese black pines, it is more warty, develops an interesting texture with time. Warts begin to show by the 5th year, possibly a little earlier, and will consolidate to cover the branch or trunk completely by 10 to 15 years. This cultivar does not air layer or root from cuttings. All true to type are propagated by grafting. Only scions grafted low into the root zone of the understock make high quality bonsai. A high graft will look more and more awkward the older the tree gets. All in all a good bonsai specimen if the graft is low enough to be disguised in the pot. Foliage management is pretty much as for standard Japanese White Pines, nothing exceptional. Probably best for medium to larger size trees, as the needles are close to normal type form for the species, about 4 inches. The key feature is the bark, a taller larger tree will provide more opportunity to show off the prime feature, the bark of the tree. Too small a design, and the unique feature, the bark, would go unappreciated.
If your wart bark JWP has needles that twist 180 degrees or more along their axis, the cultivar is not ‘Arakawa’, the most likely cultivar would be ‘Ibo Can’ which is an excellent wart bark JWP. Its main distinction from ‘Arakawa’ is its twisting needle. Otherwise they are quite similar. There is one commercial vendor that has the two cultivars mixed up. This is not a big issue, both are equally valuable as bonsai, 'Ibo Can is somewhat rare compared to ‘Arakawa’ so if you have a twisty needle ‘Arakawa’ you lucked out and got a more valuable ‘Ibo Can’.
‘Catherine Elizabeth’ - this is a short needled dwarf form of JWP. Needles are short, 1 to 2 inches without twisting. The short needles means it is good for any size bonsai, from smallest to largest. The tree begins producing small pine cones at an early age. At 10 years this will likely be less than 5 feet tall in the ground. Much smaller if container grown. Needle color is medium green to slightly blue. This cultivar does not air layer or root from cuttings. All ‘Catherine Elizabeth’ are propagated by grafting. The bark of ‘Catherine Elizabeth’ is similar to normal JWP, which means high grafts will eventually heal well enough that most of the time the graft union will not be an issue. The choice of understock will determine whether the graft union bark will blend with the scion bark. Usually there will be no problems. I have had high grafted ‘Catherine Elizabeth’ and the graft was essentially invisible except for a slight diameter change. No special techniques needed for ‘Catherine Elizabeth’, except that as a dwarf, grow will be slower, requiring more time between techniques to recover.
JWP on their own roots are hardy into zone 4. Grafted trees are only as hardy as the understock. If purchased from the landscape nursery trade, understock is likely to be Pinus sylvestris or Pinus nigra. Both are quite winter hardy. If purchased from a nursery producing strictly for the bonsai market the understock is likely to be Japanese black pine, which would mean they would only be hardy through zone 6b, maybe into 6a. Grafts require 5 to 10 years to fully fuse. Do not subject a grafted tree to freeze-thaw conditions until after the 2nd growing season post grafting. Ice expanding in the graft union can separate the scion from the understock if subjected to freeze-thaw before the union has healed enough to resist the frost expansion. If you don’t have a protected area for 1st year grafts, spend the extra money and purchase trees that are 3 years post grafting. You will have fewer problems.
Avoid wiring across the graft until after fusion is complete, Give at least 5 years before putting tension of the graft union, more time would be safer.”
Hello @Lolodigo thank you for sharing and the explanation. Which forum was it? it looks like the answer you got is pretty well explained and detailed. Thanks!
Hey! Hope it was helpful. The forum I got the response from was bonsainut. To make it a bit more confusing, Ryan on the live q&a said he would treat them as short needle single flush since the cork bark will most likely have less vigor, and the Catherine Elizabeth is a dwarf cultivar. The plan is to treat both of them as short needle this coming season, and to look for longer needles after pruning. I’ll be sure to update with my findings.