Maple bud break disaster

[Velodog2]

My understanding was that orchards sprayed water on trees to prevent frost damage. Anything in contact with liquid water, even if there is also ice present, cannot get colder than the freezing point. I could imagine this technique actually being useful to us.

 

[Dav4]

My understanding was that orchards sprayed water on trees to prevent frost damage. Anything in contact with liquid water, even if there is also ice present, cannot get colder than the freezing point. I could imagine this technique actually being useful to us.

Water gives up heat to it's surroundings as it freezes, so as long as you're constantly applying water when it's below freezing, you can prevent cold injury... nurseries have automated systems to do this, though, and rip through lots of water. For a few trees, I think it's easier to move them into and out of cover as needed.

 

[0soyoung]

I tried the fridge method years ago for some forgotten reason and the result was similar to what happened to Mach5. Severe desiccation even though I kept the soil moist.

The problem, I think, is the modern refrigerator's frost-free feature. The refrigerated space is periodically heated and rechilled to remove moisture that tends to condense on the walls as frost/ice. IOW modern refrigerators are desiccators. Enclosing your tree in a polyethlene bag (maybe requiring a supporting framework) would at least ameliorate this.

 

[miker]

The fridge method has not worked for some, but did work for me for many years when I lived in FL. As long as the soil stayed evenly moist, my trees never had a problem. The only time I ever lost trees was one time when I forgot to water for several weeks.

Now that I am up north, I am experiencing a new reality of trees that are inactive for 6 months of the year. In FL I could keep a trident in the refrigerator for exactly 3 months and get gangbusters growth for most of the remaining 9 months outside. Here, I may get 4 months of good vigorous growth, so the bonsai development time will be significantly longer, or so I am guessing. It is nice, however, to be able to just "go with nature", instead of having to use artificial means to keep trees healthy.

Btw, I am still considering bringing my trident inside into a full sun window within the next couple weeks to extend the growing season significantly. I can then return the tree to a position outside after the danger of freezing has passed. We have had around 1,700 chill hours since November 1, which in my experience is at least 3 times the minimum number of chill hours required for a healthy trident maple.

 

[Dav4]

The fridge method has not worked for some, but did work for me for many years when I lived in FL. As long as the soil stayed evenly moist, my trees never had a problem. The only time I ever lost trees was one time when I forgot to water for several weeks.

Now that I am up north, I am experiencing a new reality of trees that are inactive for 6 months of the year. In FL I could keep a trident in the refrigerator for exactly 3 months and get gangbusters growth for most of the remaining 9 months outside. Here, I may get 4 months of good vigorous growth, so the bonsai development time will be significantly longer, or so I am guessing. It is nice, however, to be able to just "go with nature", instead of having to use artificial means to keep trees healthy.

Btw, I am still considering bringing my trident inside into a full sun window within the next couple weeks to extend the growing season significantly. I can then return the tree to a position outside after the danger of freezing has passed. We have had around 1,700 chill hours since November 1, which in my experience is at least 3 times the minimum number of chill hours required for a healthy trident maple.

I wouldn't deliberately wake a tree up early for 2 main reasons. Sun exposure through a window in CT in late February and early March is a far cry from what the tree would like, which is full on sun all day long in mid to late April- only high intensity light bulbs can mimic that and your tree won't benefit at all from the "extended" growing season and the early spring growth will be lanky and thin, which is exactly what you want to avoid. Second, the air inside your heated house is exceedingly dry, and this is another stressor to the new foliage. Let the tree wake up naturally for your climate...it'll be better off for it.

 

[0soyoung]

So what happens to a plant actually when the chilling hours are not met (fa only 2/3 of the species requirement ) and the temps go up and stay up?

The buds don't crack/break. The buds may die during the course of the following season.

There is a famous (in biology/forestry circles) case of an extensive Douglas fir plantation that was planted near Monterey, CA. What they didn't realize (until afterward) was that Douglas fir buds require at least 1750 chilling hours - more than the naturally occurring hours around Monterey.

 

[Velodog2]

I would proceed as if the tree was breaking dormancy at a more appropriate date, and assuming you keep the tree from freezing temps, I think the tree won't skip a beat and you won't be losing a year of development. The key will be giving it as much sun as possible once those leaves are open... which is why you want to slow it down as much as possible now.

The problem is giving it enough light. I don't know how to get strong enough grow lights. IME any growth I get will be quite leggy and useless. I also had intended to do a bit more pruning before bud break. That's why I think this year will be mostly s loss for dev. I will do my best and see what happens.

 

[Cattwooduk]

Would setting up a small cloche net around it help? Should at least keep the frost directly off the plant even if the temps are still low. Stick a little bamboo cane wigwam over it and drape some cloche material over so it gets light and air just no frost.

 

[miker]

I wouldn't deliberately wake a tree up early for 2 main reasons. Sun exposure through a window in CT in late February and early March is a far cry from what the tree would like, which is full on sun all day long in mid to late April- only high intensity light bulbs can mimic that and your tree won't benefit at all from the "extended" growing season and the early spring growth will be lanky and thin, which is exactly what you want to avoid. Second, the air inside your heated house is exceedingly dry, and this is another stressor to the new foliage. Let the tree wake up naturally for your climate...it'll be better off for it.

You are 100% correct.

 

[Velodog2]

That's a lot of good ideas folks. Thanks. It's going to be a long 6 wks till winter is "over" but we'll get thru it.

 

[namnhi]

Is it possible to see a photo of what the buds look like now. Too many discussions without a photo is like driving in the fog.

 

[Velodog2]

I haven't checked the buds in a few days cuz there was nothing I was going to do anyway. They had been staying fairly static. Cracked open with green showing but no leaf edges. Supposed to be in mid sixties this weekend again. Absolutely disgusting. But I plan to go ahead and repot. With weather continuing like this I have no hope of stopping it. Perhaps with such a long growing season I'll be able to defoliate later in the summer and get back some development I may miss.

 

[AlainK]

So the "small palmatum" I'd posted about last fall is breaking buds. Only that one. In Maryland. In February. It's been kept w the other somewhat delicate deciduous as always in an outside basement stair well that has been dark and stable at 37-43 Fahrenheit.

37°F is 2.7777777778°Celsius : much too warm!

Acer p. in the ground can stand temperatures of at least -25°C (-13°F), much less when potted, but they do need a dormant stage.

You know, one of my first principles in cultivation is KIANAP (Keep it as natural as possible) : a potted Acer will (must) survive outside if it's reasonably protected. If your climate is below USDA zone 7, putting it in a polystyrene box with coarse pine bark, or straw (if there are farmers around, a bale of strawis very cheap: I got one for a bottle of wine three years ago) and not only will it survive, but it'll be even stronger because A. palmatum are not olive trees or Punica, or any mediterranean species: in their local habitat, they're mountain trees.

This being said, I'm sure your tree will make it. But if you still persist in treating it as a mediterranean species, "his days are counted"...

My two €uro cents' worth.

 

[AlainK]

My understanding was that orchards sprayed water on trees to prevent frost damage.

Apricots are cultivated in the south of my country. When it gets below 1.5/2°C, the flowers are damaged and the season is ruined.

People there spray water on the buds when temps get below 2°C for otherwise there'll be no fruit: (in modern societies, 0° Celsius is when water begins to freeze, and 100° Celsius is when it begins to boil)

The coat of ice that forms keeps them slightly below zero keeps the buds from being killed. The "coat of ice" keeps them at about 0°C/-1°C, which prevents them to be burnt by lower frost.

Another option is to set fire to tyres between the ranks of the trees: the heat and the particles around the buds will save them. And later, we can absorb all that shit when watching TV and there are no peanuts left so we switch to "dried apricots"...

 

[miker]

37F should actually be a perfect temperature at which to keep temperate trees such as Acer palmatum to provide needed chill hours without risking any damage that excessive cold/freezing(much below 25F to the roots) could cause to small potted trees. Sure, species such as Acer palmatum can tolerate much lower temperatures than mid to upper 30s, but in a pot, the roots are more exposed and at risk. In my experience, most temperate deciduous trees do not require freezing temperatures to enter and complete dormancy, just a genetically determined number of hours between 32F-45F.

 

[Dav4]

37F should actually be a perfect temperature at which to keep temperate trees such as Acer palmatum to provide needed chill hours without risking any damage that excessive cold/freezing(much below 25F to the roots) could cause to small potted trees. Sure, species such as Acer palmatum can tolerate much lower temperatures than mid to upper 30s, but in a pot, the roots are more exposed and at risk. In my experience, most temperate deciduous trees do not require freezing temperatures to enter and complete dormancy, just a genetically determined number of hours between 32F-45F.

Keeping temperate trees at temperatures slightly below freezing in a protected location or enclosure is actually a much easier and safer way to overwinter them. With the soil frozen, these trees essentially don't need to be watered and they are almost guaranteed not to break dormancy. I happen to agree with Alain that a low of 37F is actually cutting it too close with temperatures where the tree will start to grow. I'd have these trees mulched somewhere outside, and fwiw, Bill Valavanis has overwintered most of his collection of trees in his insulated garage in upstate New York at a temperature of around 27 F for decades.

 

[Velodog2]

The coat of ice that forms keeps them slightly below zero keeps the buds from being killed. The "coat of ice" keeps them at about 0°C/-1°C, which prevents them to be burnt by lower frost.

Actually no. The coating of ice has nothing to do with the protection. It's the liquid water in contact with the ice and/or plant material. Liquid water under standard conditions cannot be below the freezing point, and therefore anything in contact (and at least somewhat in equilibrium) also will not be (much) below freezing either. That is why you can calibrate a thermometer in a glass of ice water. If the water temp has equilibrated you can be reasonably certain it will be at the freezing point. If additional cooling occurs the water will stay at the freezing point until it's heat of fusion is given up, at which point it should solidify into ice and then the temperature of the ice can begin to drop to equilibrate with the surroundings. As long as things are wet, they are ok. This is high school physics.

 

[Velodog2]

There are many ways to overwinter acers and everything posted here is fairly similar. Based on what has been said and my experience I've been keeping mine close to the upper limit of temps most likely. My typical protocol has been to leave them outside typically mostly through December or until they have experienced a couple of nights near 25F to thoroughly initiate dormancy. As others stated that's as low as I'm comfortable letting them go. After December we typically start getting dips into the teens or below so I bring them into the controlled environment in my cellar stairwell. Typical winters that location stays most of the time in the upper thirties and it has worked well for me. This year has been different by probably only a few degrees but since I've apparently been running the ragged edge of dormancy for this one tree at least it hasn't worked. So far my other maples are still asleep.

My point and problem is that I don't have a place to keep them that is cooler but won't drop below 25F reliably. If I did I would keep them there. I lost too many trees before I began overwintering this way.

Another interesting fact is that for a number of years I brought the trees including this one into the basement itself which was in the upper 40s to lower fifties. They would even then typically stay dormant until the beginning of March. So there is some other factor causing this tree to bud early I think.

 

[AlainK]

Actually no. The coating of ice has nothing to do with the protection.

Hmm...

I've always taken that for granted since I got it from professional "arboriculteurs" (fruit-tree growers), I've always thought that people who have been in the trade for generations knew better. but maybe I'm/they're wrong...

Well, so, since we don't have acres of fruit-trees in the ground, it's best to keep our bonsai away from late frosts I suppose...

 

[AlainK]

37F should actually be a perfect temperature

No, I definitely don't think it is


miker
I'd like to see some of your Acer Palmatums - just to make sure I'm not totally wrong...