Cold Hardy Plums and Cherry Hybrids: Winter Field Notes

Cherry plums are a hybrid plum that grow as a bush, some of them introduced 100 years ago, and a few of the newer ones are canadian introductions. grow a variety of them for good pollination, these are easy to grow bushes that fruit early in the second or third year, and cold hardy to -40 .. we have a collection including most some hard to find ones.

Reading 75 year a old bulletin with the best and most up to date info about cherry plum pollinators. https://sherwoods-forests.com/Downloads/UMinnAgExpStation-Stone_Fruit-Pollenation.pdf

Nice to get the winter garden started, here are nanking cherry on day 4 .. first true leaves coming out. this is an exciting batch in a breeding effort to select some new white fruited ones. since this is seed from white nanking cherry fruit, any of the self pollinated fruits have some chance of producing white fruited offspring. maybe some will be pink?

Check on your seeds when cold stratifying, if you start them early you get some good germination in the fridge. white nanking and sour cherry seeds at 4 months are ready to grow, and will get potted up under some lights until spring. #seedstarting

Checking on sweet cherry grafted onto pin cherry, has anyone else tried this? I'll be amazed if the grafts survive, we've had quite a few nights below -35.. but a quick scratch test looks alive, though I guess cold damage might not appear until spring? the premise I'm testing is this european cultivar was reported to survive zone 4 winters and flower, and here I have it on a super cold hardy rootstock which could possibly provide some cold hardiness. The most likely outcome is that I'll regraft it lower where the snow will cover the branches, but just maybe these will pull through. #cherry #cherrygrafting #grafting

Plum seeds germinating last may. I found some in a bed that were planted two years before, the rest I let germinate in bags of damp peat moss in our root cellar before potting up. The seeds can have a long dormancy so you need to cold stratify a few months or more, then they wake up when the temperature increases. Some germinated in april, others through may and even into july so I started to check the bags once a week and pot them. Left over seed went back in the root cellar and we'll see how many come up this year. I would say that 80% of them germinated, so this winter I've gone with a longer stratification starting with one month warm. I'm talking about prunus americana, nigra, and several seedling plums I must have collected fruit from half a dozen plum trees, each its own seedlot, and also seed from the year before. I did the same stratification for our walnuts and butternuts, though they are recalcitrant meaning the seeds should be fresh and not dried, but similarly have a deep dormancy and can germinate in year two. #plumseeds #seedstarting #stratification

Plum scion wood bundles that were cut early, just checking in on the moisture. looks good. Most people cut scions in spring, but there are good reasons to do some earlier. You can cut dormant scion wood any time after the leaves drop, and it can be easier in late november here before the snow gets deep. Another reason is growing borderline or out of zone varieties, early scions before the coldest months won't have any winter die back, like a backup in case it needs to get regrafted. For long term storage, nov - april I wax the ends and throw a handful of damp peat moss in the bag to buffer moisture and condensation. then store them in a fridge. or fridges. #scionwood

Apricot trees can get big. this one found at a local orchard, species unknown could be prunus sibirica, the new growth and buds look like apricot to me. fully hardy in zone 3/ -40C owner said it hasn't fruited and shades the garden. how rare is it?

Some cherries we picked last july, first ones romance series, last ones nanking, and evans. #sourcherries #sourcherry

Siberian peach, or chinese wild peach. Prunus davidiana, similar to Siberian C with a fruit that's a bit smaller but sweet + delicious, with a thicker fuzzier skin. zone 3/4, one of the most cold hardy peaches. growing these this summer to try as a rootstock, and to grow out in different forms both on its own roots and grafted. might get to have peaches in zone 3 with some winter cover.

Gets me excited about fruit breeding. this hybrid tree is a cross between nanking (top fruit) and japanese plum, and produced a tree that grows like a nanking, fruits like a nanking with many fruit along the branches, but much larger, and hardy to zone 2. I want to try this cross. paper thankfully available without a paywall.

Canada wild plum, or p. nigra cross. upright tree form, double bumps on the leaf margins, thin point in the leaf. seeds will be hybridized since it was in an orchard next to american plums, but still a good find, stratifying these in the root cellar. really wasn't sure until reviewing the photos, good to photo document a find. #wildplum #prunusnigra

Sanoba and Mana, a couple of cool hybrid sandcherries lost to time from this 1930s SD bulletin. Both are hybrids with Dropmore, named after a Manitoba nursery that's now the Frank Skinner arboretum. I'm planning another trip there in the summer.

Canada wild plum, prunus nigra. seed collected from a remote area in northern manitoba. these are kinda awesome trees, they don't sucker like american plum, and they're an even better pollinator, the best pollinator for hybrid plums. if you have a plum tree, you should also plant one. I have a limited number grown in pots this year, and I'm reserving most to plant and graft around our property. something cool about a native species, planting feels like restoring the ecosystem and just increasing biodiversity. planning on planting many of these, and ribes americanum along our trails and forest margins where they can get good sun exposure #canadaplum #wildplum #ribesnigrum

Seed starting with a selection of prunus. #seedstarting #plumtree

This is something I feel driven to do, breeding new hybrid fruits, it's mad science gardening. badass to find a good quality chum x apricot! last page is from a local arboretum, an early attempt at the black nanking. https://conservancy.umn.edu/server/api/core/bitstreams/9c684c14-7509-4b78-a803-0bf01a64aa28/content

Western sandcherry, prunus besseyi. hansen bush cherries. such a cool plant, the fruit is super tasty (unlike the related eastern sandcherry prunus pumila), it's one of the parents of most cherry plums and the black nanking, and it's a super cold hardy rootstock. I'll be grafting apricots and other prunus onto it in the spring, and generally growing many of them for no other reason than to plant around our nursery, they should do well in our sandy soil #sandcherry

Someone else noticed you can graft toka (prunus simonii hybrid) to chokecherry... in 1887 in this update from the michigan horticultural society. google books search https://www.google.ca/books/edition/Annual_Report_of_the_Secretary_of_the_St/wHU5AQAAMAAJ?hl=en&gbpv=1&dq=prunus+virginiana+grafted&pg=PA100&printsec=frontcover

Happy to announce that we've been added to the list of licensed propagators for the Boreal series haskaps bred at U of Sask in Saskatchewan, Canada. The varieties we'll be propagating include Aurora, Borral Blizzard, Boreal Beast, Boreal Beauty, and also the cherries Juliette and d'Artagnan. Photos courtesy of the U of Sask Fruit Program. #haskap

Fog condensing into ice crystals on these toka plum branches

Toka plum on wild chokecherry grafts. This one hybrid variety had the best compatibility and put on 3-4ft of growth last year. I've left them to overwinter with budding tape in place to add a little insulation from sun scald, hoping these make it through the winter. later this spring I'll be trialing Toka and a few others as an interstem on many more prunus varieties with the goal of finding compatible combinations for zone 3 hardy prunus to graft onto the prolific choke cherry around most of Canada. #grafting