Thank you for this great article and for the note on the Hardy Kiwi Issai. Issai is just one of many hardy kiwi varieties, of which I have grown five others, and Issai has the most "true" kiwi flavor. And I have a sport from Issai which we have found to have a "cleaner" Kiwi flavor and seems to be sweeter than the original Issai and still has the desirable plant growth attributes of Issai and the ability to bloom on one year old wood like the original. Just a note: the Issai is appropriately named as in Japanese Issai "means one year old"
One of the major hurdles for hardy kiwi's in commercial production is that each fruit must be cut from the stem much as oranges are harvested. Imagine harvesting large grapes one at a time by cutting them from the stem and the fact that there can be as many as 100 lbs of them on each vine!! .Can we say extremely labor intensive!
Thank you for sharing your comments. Are you a commercial grower? What other hardy kiwi varieties did you grow besides Issai? That's interesting about the harvesting. I see $$$ adding to their cost!!! Since I learned about kiwi grapes, I've been looking, but haven't seen them in our local markets. I can't wait to taste them someday.
To your question I have tried the following varieties:
Kens Red- reasonable flavor, plant has been somewhat fragile here in NC, is proving to have a good crop one year and none to small the next. I have removed this one.
Meyers Cordifolia- Sweet with a flavor somewhat reminiscent of a fuzzy Kiwi.
Fortyniner- larger fruit than Cordifolia, Sweet, taste less like fuzzy kiwi
24-47- Similar to Fortyniner
MSU- largest of the hardy kiwi's, sweet, rather dull non-kiwi flavor.
Issai- Sweet, good kiwi flavor.
Issai-sport, some are taunting this as 2nd distinct variety of Issai.- Sweet best Kiwi flavor of the varieties I have tried to date.
While the fuzzy varieties can be picked green and are often stored 12-18 months hardy kiwis will not ripen well once picked. Trials have shown they need to develop sugars to about 18 brix before picking to have a reasonable flavor. Most will keep 3-7 days with reasonable quality.
From what I see they could do well in a local market but, for distance shipping would have to be handled like blackberry or raspberry crops with similar losses. This with the labor cost have been big deterrent to commercial development.
One note: The Issai sport mentioned above may have an advantage. Once they begin to ripen to about the 18 Brix level most can be shaken from the vine which I am watching and could solve the picking problem. Unlike the original Issai, this sport is more rounded in shape. They ripen over about a 3-4 week period.
Hi Steve, thanks for such great references on the hardy kiwi varieties that you've grown. Do you prefer to grow the hardy kiwis on trellis' or along a fence? Sounds like your Issai sport has potential. Good luck with it.
As I was looking up more information on some of the varieties you mentioned, I came across this good photograph of Fortyniner Hardy Kiwi (Actinidia arguta). I like the plants burgundy stems too.
If you grow them on a fence it will have to be sturdy. While the Issai does not have a real aggressive growth pattern like the other hardy kiwis, it still becomes a massive plant that needs some serious pruning from time to time even with ongoing training. I have never left an issai go as far as it wanted but if you had a fence and it could go I would expect it to travel 10ft in a couple years and see no reason why it would stop at 20ft unless stopped. All other hardy kiwis will put out as much growth in a year as Issai does in two or three years, If you know the kudzu plant, there are times I think the Kiwis must have some kinship with them by the way they grow once established.
My trellis is not tall enough and is shorter version of the trellis recommended by the university of Oregon but, as you can see in the picture you referenced, the fruit grows on the inside of the plant and if the trellis is tall enough you should be able to pick them from underneath quite easily.
Just a note. All hardy kiwis including the male with the exception of Issai have the red or burgundy leaf stems you mentioned