By Robert A. Purvis
The winter of 1988-89 was a “test winter” in both Southcentral Alaska and in the Interior, with temperatures dipping into the -30 to -40°F range in Southcentral and into the -50 to -70°F range in Fairbanks and vicinity. As such, this past winter can provide valuable information on how well various varieties of tree fruits and berries survive extreme cold, specifically during the three weeks from approximately January 15 to February 6, 1989.
The 63-year-oid sweet cherry tree in Homer, owned by Fred W. and Margaret Anderson, suffered no winterkill. I was able to get a “take” on a branch tip grafted to a GM rootstock. Deimore Schmidt’s Parker and Clapp’s Favorite pear trees, planted in Homer in 1985, had suffered only slight winterkill on 1988 growth based on observations March 19 (By ‘‘slight” I mean that 0 to 25% of the 1988 growth was killed; by “moderate,” 25 to 50%; by “significant,” 51 to 75%; by “severe,” 76 to 100%.) Deimore moose-fenced his orchard area successfully; furthermore, he put up cages with burlap around the tops and around the trees themselves. There was at least a foot of snow on the ground when Homer had its near record low of -27°F.
In Hope, the low for the winter was -35°F as recorded at the home of David and Sheiia Hanson. Their Scout apricot on a Manchurian apricot rootstock, planted in 1988, had poor, weak growth in 1988. Although the cambium was alive under the bark in March 1989, the entire tree was dead by May when I inspected it. The Scout was about 4 years old. Hank Mori’s 5-year-old Manchu apricot, like my Scout (acquired in 1987 from Gurney’s), survived the -35°F and was leading out well by May 20, This tree was planted on a gravelly, well-drained terrace that slopes southwestward from Henry’s One Stop, his store– the Hanson’s were-on a mound on level ground. There was slight to moderate winterkill on the Manchu, which also was on a Manchurian understock.
All the apple trees which the Hanson’s, Hank Mori, and Chuck and Linda Graham had bought from Whitney’s Orchard & Nursery and planted in June 1988 were alive. At Hanson’s, their Vista Bella on Ranetka was leafing out on the tips of many of the branches. Glenorchie and Geneva Early, also on Ranetka, suffered a few inches of winter-kill. There was significant winterkill on the Oratia Beauty, which lost all of the branches it grew in 1988. There was, however, little winterkill on the central leader. Inasmuch as this cultivar is a Gravenstein sport from New Zealand, it is not surprising that it suffered more winter-injury than the others. There was at most 1.5” of winter-kill on the Mantet and the Flurry apples trees they’d planted in 1988. The Hanson’s provided adequate moose, rodent and sun-scald protection for their trees.
Growing on the terrace with the Manchu, Henry Mori’s Flurry, State Fair, and Norland had negligible winter-injury. At Graham’s, the same situation applied for their Geneva Early, Summerred, Flurry, and Whitney’s Earlygold. The latter is a Golden Delicious seedling which ripens much earlier than that commercial apple. The Graham trees are in an open field a few hundred yards from Turnagain Arm. Most of the Hope apple trees had flower buds on them and were beginning to leaf out as of May 20.
At my orchard in south Anchorage, elevation 610’, the low this winter was -34° F, with about two feet of snow on the ground at the time. There was no winter injury whatsoever on my Norland (planted 1988), Oriole, Yellow Transparent, and Whitney Crab (planted 1986), Wealthy and Red Duchess (planted 1983). These trees are all on Antanovka except the Whitney and a Hazen which are on Malus sargentii. There was loss of perhaps 2-5% of the 1988 growth on my Hazen and Mantet (rootstock unknown), both planted in 1986.
I over-wintered some pears, plums, and apples in pots behind by greenhouse. They were mulched with leaves and snow, but there was still a lot of wood exposed to the elements. I was surprised and pleased to find that a Superior Plum I’d grafted to a Manchurian root- stock in 1987 had no winter-ki!!. By contrast, the Superior on americana in the yard, planted in 1985, lost 52% of its 1988 growth to winterkill. The LaCrescent Plum on P. americana, enduring its second winter outdoors, lost about 10% of its new growth.
My potted trees of NY 394 (ripens before Yellow Transparent) and NY 652, both on Antanovk suffered no winter injury. The Lyman’s Large Summer on a Beautiful Arcade stock had slight winter-kill. A Merton Beauty on Ranetka, a 3-year-old tree, lost 50% of its new. growth, however.
There was no winter-injury whatsoever on my Meteor pie cherry, planted in June 1988 (good drainage and early cessation of growth probably explains that.) In fact, it began breaking dormancy before any tree in the yard, on April.18. A Rainier sweet cherry, planted in Sept. 1986 as a 2-year-old tree, lost approximately 15-20% of its significant 1988 growth to winter-kill, based on the amount of wood that had not leafed out as of May 30. I put a rubber trash barrel over the tree hours before we had our -34°F, but I don’t believe it was any warmer inside the barrel than outside.
My Tyson pear on Old Home x Farmingdale 333 had slight injury to the tips of a few branches and that was all. The same applied to a Ure, Nova and Pioneer #3 pears on P. communis root stocks. The biggest disappointment was the Hudar pear acquired from St. Lawrence Nurseries in 1987. It grew vigorously in 1988, but the cambial tissue died in 40% of the new growth (80” of 208”). The tree went into deep dormancy, unlike all the other pear, apple, and plum trees, and it took four days of sweating out the tree (swathed in wet burlap, encased in a plastic bag, held at 60-65°F in the garage) to make green buds start popping out of it.
In Doug Tryck’s Orchard on Rabbit Creek Road, the low was -20°F. This was no challenge for his Summer Crisp pear, planted in 1987. Moreover, Summer Crisp withstood -34° to -38° F for Dick Green, also, in midtown Anchorage, with only a bit of tip burn. At Joe and Alice Brewer’s home in Spenard,-30°F caused slight amounts of winterkill on the Sauvignac pear they planted in 1988 and moderate amounts on the Waterville pear (I bought the trees from St, Lawrence in 1987 and overwintered the Waterville outdoors, the Sauvingnac indoors, that winter.) Both trees were wrapped in burlap, the Brewer’s Goldcot, on a Manchurian apricot, had live buds 21” above the ground, which was also the snow depth. It, too, was fully swathed in burlap. It goes without saying that I couldn’t find any winterkill on their 23-year-old Yellow transparent and 13-year-old North Star cherry trees.
Chapter co-founder Rich Raynor has been growing and keeping records on fruit trees since 1983. I gave Rich an 8.5’ high, healthy, blossoming Toka plum on P. americana in 1988. The tree, acquired from Alaska Greenhouses in June 1987, lost about 30% of its 1988 growth after -38°F. This was its second winter outdoors in a pot, now the tree is in Delmore Schmidt’s orchard in Homer.
Rich’s Hudar and Parker pears survived their fourth winter under snow in west Anchorage. I was pleased that the portion of his Pioneer #3 on P. communis above the snow had survived the -38°F. With no winterkill—I’d grafted the tree in April 1987. A Giffard pear I’d grafted to P. communis in April 1988 had grown vigorously (about 18” of new growth) in Rich’s yard in a pot in 1988. After -34°F in west Anchorage in his mother’s yard, it was budding out and had perhaps 1” of winterkill on each of its two branches.
Another Giffard I’d grafted on OH x F333 and given to Erik Simpson also survived the winter outdoors with no winterkill.
Among the plums Rich had was an Ember, which I’d acquired from Stark Brothers in 1987. The -34°F (its first winter outdoors, second in Alaska) killed 30-50% of the Ember’s 1988 growth, but it was leafing out as of May 29. Pembina as usual, had no winter injury for Rich in west Anchorage. His 6-year-old Toka in that spot had severe winterkill and only a few green buds as of May 29. His Superior plum survived by virtue of being completely under the snow, but his Stanley plum had only slight winterkill above the snow line, and likewise his Compass cherry-plum.
Of the apricots Rich has tried in west Anchorage, only Moongold is alive today after four winters, and that by a thread, there being extensive injury to its trunk. We were surprised to find nothing more than slight (5%) winterkill on his Montmorency pie cherry. His North Stars likewise did very well, but there was much injury to an Early Richmond pie cherry above the snow line. His Stella, Sam, and Van sweet cherries all had a number of blossom buds on them May 29, but in every case they were alive only to a height of about 2-2.5’ above the ground. The Hardy Giant sweet cherry survived but has no flower buds.
Rich’s Hazelbert survived only below the snow, but his Chamberlain butternut trees brought most of their wood through the winter above the snow line. We found no winterkill on his Oriole, Red Duchess, State Fair, Norland, Yellow Transparent, and Mantet apples after -34° to -38°F, but his Beacon was still dormant, as of May 29.
What conclusions can be drawn from this winter? One is that trees which stop growing well before fall arrives have a much higher likelihood of bringing their new growth through the winter, because the growth is fully hardened off. The winter showed that the hardiest pears, in approximate order of decreasing hardiness, to be Summercrisp, Pioneer #3, Ure, and Sauvignac. It appears that Waterville, a Vermont pear, is significantly less winter-hardy than Sauvignac, a Quebec City pear. Giffard shows considerable hardiness and it ripens about the same time as Summercrisp, probably about September 15 in Anchorage, Tyson will be later, but it too is well worth planting if they’re all as healthy and hardy as my tree was. Hudar, in spite of its good qualities of precocity and early ripening, will probably need more winter protection, a vigorous rootstock (P. communis), and strict regulation of fertilizer and water application. I recommend that Ure be grafted on P. ussuriensis rather than P. communis. It should enhance the tree’s already noteworthy hardiness, improve its vigor, and should get it leafing out sooner in the spring. Summercrisp also, on Ussurian, might even work in sheltered locations in the interior.
On plums, Ember appears to be well worth trying, but Pembina has performed the best, .over four winters’ time. Toka and Superior need strict regulation of fertilizer and water and would be best grown on P. salicina manchurica.
Concerning apricots, it appears that Goldcot will not survive below -30°F above the snow line, but under some conditions Manchu can—it seems significantly hardier.
Most of the apples appear to be hardy down into the -35°F to -40°F range with the exception of Merton Beauty and possibly the Oratia Beauty. Because of the statistically insignificant numbers of trees of each cultivar observed, however, these conclusions can only be regarded as tentative.
http://genericviagrabestnorx.com/ – generic cialis canada – best place to buy cialis online – viagra without a prescription – http://viagraonlinecheprxfast.com