I recently got scionwood that now is being stored in the refrigerator at 33 F. This wood will be stored for the next 3-4 months, and I am worried that they will sprout in the fridge. Is this likely with sweet/sour cherry? Am I able to freeze them at 32 while still being able to graft them successfully in the spring? Has anyone experimented with this?
I have noticed that my sweet cherry scions have buds that have become green at the top, can I stop this process?
(Here’s a pic of one of the buds)
Generally you want to aim for 37 in a zip lock type bag.
Why 37, what’s the reasoning behind it?
I remember people saying you should be around 33, but not go down below freezing. Same as the topic starter, I’m not sure why. I would be interested to see if somebody can show research supporting one of the approaches.
I say 37 because you do not want the wood to freeze and most refrigerators are not capable of keeping things that accurate. If you set to 33, it is almost certain that you are going to have frozen areas somewhere in there. I keep my chest freezer set at 40 for scion wood because it tends to be colder.
https://growingfruit.org/t/scion-and-budwood-storage/12250?u=disc4tw
Here are some other threads with some thoughts on the topic over the years.
I’ve been reading some threads where @Olpea freezes peach scions, defrosting them every few weeks. I was wondering if that can be used with any scion, and whether that technique of storage damages the scion.
37 to 33 is a pretty big difference. I would understand 34 or 35, I think most modern refrigerators can keep temperature stable within 1-2 degrees of the nominal one.
I still don’t understand why twigs can easily survive, just to give an example, 10 F while on a tree, but after being cut would be destroyed by 32 F in a fridge.
Maybe 33 is a bit low, especially since I store my scions at the back of the fridge. I am getting a thermometer soon so I’ll be able to more precisely measure. Interested though if freezing is possible without causing damage as the scions are less likely to come out of dormancy.
As far as I understand, the idea is to keep things dormant while also reducing the chances of mold and fungus growing, and standard refrigerator temperature is pretty good for that.
I agree, but once chill hours are met don’t scion start to break dormancy?
Not always. I’ve seen some sticks bloom in a ziplock in the fridge while others next to them continued staying fully dormant. Cherries and low-chill peaches and plums are notorious for coming out of dormancy while still in the fridge.
Has anyone found a solution to this.
I have a dorm fridge and routinely keep it about 30F. I keep a thermometer in it. I’ve frozen apple, pecan, peach, plum, and pear. All of them perform well by freezing, then occasionally allowing them to thaw out (generally by running water over them, but sometimes by leaving them out long enough for the ice to melt back into condensation.
I prefer this method because it hold the wood in “suspended animation” really well, without damaging it. Last winter a forum member sent me some peach scions, but it took a week or more to get here and the buds were swelling pretty good, when I got the wood. I immediately put the wood in the 30F fridge, held it there for several months before it was time to graft.
I grafted the wood, and as I recall, still had 5 out of 5 takes. One died later this summer, but still have 4 out of 5.
Thank you Olpea!
@Olpea I was reading stuff on the web and someone said if you collect the scions below freezing you can freeze them, but if you collect them in warmer temps you shouldn’t exactly freeze. In your opinion is this true? (Not sure what temp mine were collected at but considering where they came from it was likely around 50-60F. As a matter of fact, the area where these scions came from, temps hardly drop lower than 40F in the coldest part of winter) Or does this not matter?
I always try to collect my scionwood when temps are above freezing. I’ve read there is more water in the dormant wood on warm days. I’m always worried about the wood drying out, so I want the wood the max hydrated.
I’ve not had any issues lightly freezing the wood. The issues I always had (before freezing the wood) were that the wood always broke dormancy in the fridge, which makes it harder to graft. Freezing the wood completely took care of that issue for me. I’ve been freezing scionwood for over a decade now.
I would emphasize the temp never gets below 30. I don’t know how cold it would have to be to damage the wood, but 30F doesn’t damage it.
Thanks @Olpea, one other thing that I found while reading was that antifreeze proteins are responsible in allowing plants to survive in these lower temps. I got these scions from California where temperatures as a mentioned never really drop below 35-40 in night, and are around 50 in the day, would this affect the production of antifreeze, or have an affect on the scions at freezing temperatures?
I am a little perplexed by this subject as well. Winter is long here in Spokane. Sometimes it is really cold, sometimes its warmer and rainy in the 40s and 50s. Frequently, nighttime temperatures are in the mid to high 20s while the daytime temps are in the mid 30s and this daily freeze/thaw cycle goes on for weeks. The trees don’t seem to care. I’m trying to imagine why the scions care either. All that being said, I feel like I want to keep my scions close to freezing in storage (like 33), but don’t get concerned if things dip lower from time to time.
I think this would affect the “antifreeze” in the shoots and corresponding scionwood. But those temps are still low enough to start endodormancy.
The thing is that 30F is so far away from what most peach trees can take before the leaf buds and wood are killed, that I can’t imagine 30F doing any harm to the scionwood.
I remember the big “Easter freeze” in 2007. I don’t remember the exact temps before the cold front rushed in, but it was very warm (I think close to 70F.) The trees were fully leafed out. Then the cold front moved through overnight. There was a howling north wind all night. By morning it was 18F. As I recall, it killed just about all the foliage on all the trees except peaches. It burned the peach foliage, but didn’t flat out kill it.
Here is an article which discusses endodormancy some. They discuss how it helps increase endodormancy by cooling down slowly. But again, my opinion is that 30F is such a mild freeze, little to no endodormancy is needed to protect the leaf buds and wood from freezing to death.
I have been successfully storing scions of sweet cherry, peach, pear, plums, apples for many months and they NEVER come out of dormancy. I cut the scions the first night the temperatures drop to -15C, November here usually in my zone 3. I then put them in a zip lock bag in a buried to the rim Home Depot bucket in my garden, on the north side of the fence. I cover the bucket with a big bag of leaves and snow . The temperatures in the bucket are amazingly constant. The coldest it has ever dropped down to inside the buckets (with -40C air temperature in late January) is -5C. None of the scions of any variety are ever hurt by these temperatures, and they keep for several months without ever coming out of dormancy. When the temperatures hit +4C in the bucket (mid April here) I move the bags to my basement fridge and start grafting in late April. The scions are never winter damaged, nor are they ever damaged from months at 0C to -5C storage in the winter. I did a short YouTube video of this method for those interested.
Amazing Scionwood Storage Method
