Overwintering with a twist

Will_Heath

Joanie,

It is more than just soil temperature, there are many factors that come into play. The temps, the length of day, the soil temps all come into play. Each sends signal's to the tree to start preparing for dormancy, to cut off chlorophyll production to the leaves, to store up starch in the roots, to create and store surplus sugars, etc. All these things play a part, miss one and the tree will suffer. You can not just turn down the heat one day with a switch and expect normal dormancy, it is a long process that starts shortly after they come out of it and slowly builds back to it again.

Think of dormancy as a sort of sleep. We sleep just fine as long as everything is what we need. However, turn down or up the heat, add some noise, change surroundings and we have a hard time sleeping...a few days of this and we suffer, amazingly we can adapt, trees have a much harder time, in fact most die instead.


Will

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rockm

Joanie,

I applaud your determination. I understand your finer points. You seem to be missing the finer points on the other side though.

The basic problem is you don't seem to have an idea of what "cold" is ;-) That goes for many of the posters in "warm" areas, just as many Northerners have no idea of what "hot" is. I mean that humorously--honest.

An air conditioner is woefully inadequate as a chilling mechanism for overwintering plants, same is probably true of circulating cold water through pipes (which seems like it would be expensive to install and run) Temperate plants need COLD, some need more than others. Temperatures must be below 40 to satisfy cold requirements in some species. Some species require lower than that. To complicate matters, soil temperatures must remain below the point where roots become active--but that activity depends on satisfying the "chilling" requirement of the plant. That means temperatures have to remain relatively constant below 40. No spikes to 70 in the daytime... If those requirements aren't met, the plant doesn't go dormant and will wear itself out with growth. That's the typical fate of some trees in this situation.

The summer, however, could present additionaly problems than for temperate zone plants two or three zones out of their climate tolerance. Plants' photosynthetic processes depend on lower nighttime temperatures during the growing season. This is a relative thing related to species. For many (not all) temperate zone plants, nighttime temps that hover in the mid to high 70s or higher for a few days can slow them. If summers are hot and a trend towards warm nights continues, many temperate zone plants can't cope. They decline and die. This can be gradual, or it can be total collapse.

I've seen this even here in Zone 7. I fell in love with Larch a while back. I ignored the advice of some bonsaiists in the area who said the plant wouldn't work here. "Hah," I said. They just don't have any talent. I CAN DO IT. I went out and got a nice one from a seller in Pa. It thrived the first season I had it. The second, budding was a little less lush. The third season, there was no new budding, needles (those that hadn't fallen off the plant) started going a little yellow and brown The summers during that time were among the hottest on record. Nighttime temperatures had rarely dropped below 75, hovering in the upper 70 and mid-80s. Daytime temps were in the mid-90s to 100s in August.

Larch is native to very cold zones--like Zones 6-2. After three years, I caught on that it was simply too warm to keep such a cold-loving plant in my area. I sold it to someone who live in Zone 5 in Ohio. It's recovered and doing very well there. From that experience, I began to understand that most plants have a leeway of one neighboring zone either way. That tendency can be exploited-- to a certain extent--if you want something other than "what everyone else has" in your area.

I have a Texas Live Oak (Zone 7 and and Bald Cypress (same) collected in La.. Have had them for years. They have no problems with the heat ;-) here in Va., although the live oak gets special protection in the winter in a an unheated polytunnel at a local bonsai nursery. I have no larches, as beatiful as I think they are.

For what it's worth, there are some cultivars of Japanese maples that take heat better than the rest. A search on some specialty online maple nurseries will turn them up. They aren't cheap.

Also, for what it's worth, if the local established high-end nurseries in your area don't sell maples, quince, or other colder weather plants, they probably won't grow for you. Take what they sell as an example of what's possible--although one high-end nursery here has been selling banana plants for landscaping use...go figure. Plunking money into a losing proposition can be fun and sometimes informative, but sometimes it's just plunking down money for nothing...

Joanie

Mark, I understand and am listening to your argument. So let's go one more time... I am going on the assumption that you, and Will, and Howard (those who don't suggest trying this experiment) know more than I do, and have experience to back you up. But just to touch on a few things to show that I'm not some lightweight thinker here....

Again, my zone is NOT HOT! Here is a chart of average temps. Keep in mind that I am less than two blocks from the beach, so I am even cooler during the summer. The chart contains the averages across the city, and the city goes miles inland. It is rare for it to hit 85 here at the beach, and it quickly cools because of the onshore breezes which are moist and cool. Nights are always, always chilly. It's a tiny pocket of cool, and a heavy marine layer in June and July hovers over us when the heat of inland air hits the ocean's edge.

Our nurseries do carry wisteria, Japanese maple, quince, and many trees that are temperate. In town, wisteria covers the arbors of several patios. Japanese maple trees aren't uncommon yard trees. My concern was reading so often that they require so much dormancy... a certain amount of low temp etc.... to really thrive. So either the trees here are some sort of freaks, or all that is said about them is incorrect or can be taken with a grain of salt. As 'Nut said, he has them, and they are fine. I wanted to give my trees the BEST climate for their needs, and the dormancy that will bring out their colors so that when I do get to a more advanced stage, I can present trees that are brilliant in their color and leaf. There is no question that the trees live here, and in the ground they do just fine, but hearing so much about the dormancy that seems to be an integral part of their growth, I wanted to go above and beyond.

I talked to an old time club member yesterday in a similar climate to mine. His trees achieve a sort of dormancy just with the shorter days and cooler nights. He has had Japanese maples for many years and one is on the cover of his new book! (more about that later) He convinced me that his grow just fine, except when we get drying winds, that ruin the look of the leaves in the fall but don't hurt the tree. He said to put them in the little shed, keep it cool, (not air conditioned, just cool, as it stays anyway) keep them moist but not wet, and they will do great.

I think that the problem has been the zone comparisons. The zone compares where the frost hits, right? And maybe the number of growing days or something? But it does not take into account the heat, because if it did there is no way that Carlsbad would be a higher zone than places in Florida! Yikes! It's at best a misleading comparison. But a more complete picture would be too involved for most purposes.

I'm going to play with a few ideas. I'll spend very little money and buy things that can be used elsewhere. (We always wanted a fountain anyway) Using identical trees in several situations will give us an idea, over a couple of seasons, whether it helps or whether the complexities of dormancy are really beyond our ability to manipulate.

Thank you and so sorry to frustrate you! I can hear you all banging your heads against the wall!!

Joanie

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Joanie

Now here's something interesting....weather in Japan.... They get hotter in the summer, particularly at night... and only about ten to twelve degrees cooler in the winter months at night.

Joanie

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rockm

If there is success in keeping such bonsai in your area, I guess I'm a little confused about what you're asking. You seem to be in a microclimate that belies your climate zone.

Are you looking to create a "better" artifical environment to induce "better" dormancy? If that's the case, good luck and happy spending ;-)

USDA Zones are based on average minimum temperatures and nothing more.

"So either the trees here are some sort of freaks, or all that is said about them is incorrect or can be taken with a grain of salt."

Neither is true. Growing bonsai has always been a very very local thing. We're not incorrect and you're not either. The trees around you aren't freaks. It's more subtle than that. If you've got a local climate where these species are being grown, then have at it.

Joanie

I did explain that. A while ago. Several times.


Yes, because everyone says that they need it. That it is the difference between just surviving and thriving. That it gives better leaf color, flower and fruit. Etc.


So why keep comparing us to Florida zone 9 and 10?


(bang bang bang bang oh my forehead bang bang bang) So all that talk about how cold they need to get, how cold the soil needs to be, how short the days need to be, that they break dormancy if it gets too warm, etc.... all the factors sited in the debate we just had.... suddenly doesn't apply?

Some days are just confusing.

Joanie

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HB Smith

We all experiment with different plant material. I am not trying to stop anybody from doing whatever they want. I am simply trying to provide a realistic basis for expectations, and encourage focusing limited resources on what will thrive in each's area. Learn about soil, water, shading, fertilizer, bonsai technique, cold hardiness. These variables can produce a masterpiece in anyone's backyard.

I would like to grow larch, stewartia, zuisho, that satsuki I mentioned earlier in this thread. But the bulk of my resources is invested in hardy material for my area. Juniper, black pine, trident maple, holly, elm. I have been told by a bonsai professional that I have grown black pine stronger in my area than they can in Japan. This means a lot more to me than keeping a struggling stewartia alive in the corner of my greenhouse.

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Sincerely,
Howard

www.BonsaiSmiths.net

rockm

"Yes, because everyone says that they need it. That it is the difference between just surviving and thriving. That it gives better leaf color, flower and fruit. Etc. "

You're the one that has to decide all this. We have laid out our experience with similar species/situations. You are the one that has to make the judgement based on your observations, local experience, etc.

"So why keep comparing us to Florida zone 9 and 10?"

I based my recommendations on the "ZONE 11" in your profile and the "coastal desert" description in your info.

"So all that talk about how cold they need to get, how cold the soil needs to be, how short the days need to be, that they break dormancy if it gets too warm, etc.... all the factors sited in the debate we just had.... suddenly doesn't apply? "

SURE THEY APPLY. That's the way plants work. It's a matter of degrees of how efficiently it works though. Is your area ideal for Japanese maples, probably not. Will it work, obviously, given your descriptions, it does. I'm getting a headache. If the plant grows in your area, it grows in your area. It's needs are being met, apparently, so why ask us on the Internet if it's OK to grow it or how to make it more colorful/healthier/fruitier/more fantabulouser? ;-)

What you seem to be trying to do is pump up color, health or whatever by trying to somehow recreate a climate that's perfect for maple. That ain't gonna happen. Nice dream, but you work with what you've got. Color depends on many things, cold temps being a minor influence, compared to say, sun exposure.

Japanese maples with perfect vibrant foliage even in their home range are difficult to achieve--even for experienced growers. Many factors short circuit them--wind, too much summer sun, too little sun, too much humidity, too little humidty--Leaves are fleeting and their condition changes with every year. Chasing the goal of perfect spectacular color every year will leave you mostly disappointed. It does me and I live in a cold zone ;-)

As for optimal growing conditions, your area is on the warm side for Japanese maples, that's the way it is. It is not, apparently, warm enough to slow them significantly (although how long they last in-ground or in containers would be an interesting question for the locals who have them).

I'll stop smacking myself in the head with this shovel, if you stop banging your head on the wall ;-)

Attila

I have a japanese maple (Acer palmatum 'shindeshojo') growing in my backyard for the fourth year now - beside others growing in nursery cans. The trunk is already 4 inches thick, and the tree is about 5 feet high (it started as a 1 gallon plant). It is doing great in full sun all day long, with some afternoon shade. It is getting more and more vigoruous every year, absolutely happy. I am missing the vibrant fall color, but the tree makes it up for me in the spring, when it displays astonishing scarlet red and orange "fall colors".

And I live 10 minutes east from downtown Los Angeles, where temperatures are a little higher than in San Diego.

The japanese quinces are doing just fine as well, they just need some shade cloth in the summer, no need to spend more than a few bucks on that.

The wisterias are dooing too good. I whish they were a little less vigorous so that I wouldn't have to battle with them for my backyard every year.

No special arrangements for me! If the plants complain about the heat, I just tell them: DEAL WITH IT!


(I experiment with a lot of 'out of zone' species here, and I've crossed a few of the firs (abies) and larches off my list, but I've never seen a place that can accomodate such a large variety of plants. So, Joanie, stop trying to spoil your trees. It can't get any better than here.)