I would like to move a number of 2 year old maples out of the freezing tempeartures into our unheated garage if possible. i intend to repot them in the early spring. The garage has a regular sized window, but the garage is not bright, not well-lit. How much light do maples need in a situation like this? is this safe or should I look for another solution? I thought I could put them right in front of that one window. as always your input is much appreciated.
Can't say I know the exact answer, but will tell you I usually bring in cold intolerant tropicals & shuffle them around my garage too. One thing is certain, a frozen pot (roots) is not good. The normal cycle of a maple is to be naked (deciduous) in the winter. Remember, the leaves don't need to be there to produce food-that part is done for this year. Water only when pots are dry. Too wet is worse than too dry. Daylength/sunlight is probably important to bring the tree out of dormancy. On warmer winter days I often drag plants out of garage until temps nose dive again. I'm a nurturer by nature, this may not do any good, but certainly makes me feel like I'm "helping" it survive winter. Some of my tropicals are so old, they're like family members. Hope this helps some. Oh yea - I vote for in front of the window.
I store a number of potted JMs in an unheated garage every winter. There are about 50 in there right now along with all my geranium baskets from the patio. It's an insulated garage with three windows (south, west, & north) that are each 3' x 5'. I set potted maples down on the floor (want to keep them cool to keep them from breaking dormancy) without much concern about their proximity to a window. Inside the garage, temps usually stay in the 30's (F). But, these temps can dip below freezing if the outside temps get down in the teens. Under these conditions, I'll actually pull the geraniums into my house for a few days until things warm back up. It would probably have to get below zero outside (low teens inside) before I had much of any concerns about the maples. I'm zone 6 and we haven't seen sub-zero temps in the past few years. When it happens, I'll probably invest in a small space heater to insure the health of my trees. I built the garage four years ago and I've yet to lose a geranium or maple that has been stored in it to winter damage. As far as light requirements, I'm not sure dormant maple trees would need very much light to survive. I entombed a small, grounded JM in a cylindar of straw a couple of winters ago because I really, really didn't want to lose him. The only thing sticking out was the tips of a couple of twigs, so most of this tree dealt with pitch black conditions for about 4 months. Maybe I'm just lucky, but the tree showed no ill effects from this treatment the following spring. Bryan
Your maples will not require any light during dormancy. Make sure they stay cold enough not to break dormacy early and move out when the risk of hard freeze has past. Be careful not to get youself into a predicament by leaving the pots in a garage that becomes to warm as spring approaches. If the trees break dormancy in the garage and push leaves, you will be forced to provide them light when the risk of freezing may still be present outside. To put them out in this situation could mean a big risk to the new foliage. I live in a pretty mild zone and while we see hard freeze and some winter temps in the high teens, we usually stay closer to 30 degrees F most of the time. I overwinter everything outside and do not protect which means at some point in the winter the pots will freeze solid, or close to it. If your pot has adequate moisture to protect the roots in a freeze, it will likely survive just fine. While you may get some degree of root kill, it will not be the death of the plant. If you repot anyway, you can always trim away and damaged root mass. We have to think in terms of the natural state of things, where a plant will balance root kill and top growth as part of the natural state or things. If you have a few plants, drag them into the garage. If you have many, your garage many not be big enough. Low temps around 20F no big deal; regular lows around or below 10-15F, you might need some protection depending on the age of the plant and the pot size. The frozen pot problem will not be nearly as bad as frozen twigs and branches from icy winds.
Thanks very much for the replies. I'll use the garage, then. Temperatures here are usually not too severe, in terms of temperatures but sudden exceptions can occur. I have maples in big wooden barrel containers outside, which I wrap during winter, but, mjh1676, you say that I should make sure to protect them against icy storms, freezing rain, hailstorms, etc, - and icy winds that attack the upper part - if I understand correctly. Thanks again. I am learning a lot in this forum.
Just to clarify, there is always a possiblity of physical damage from hail, ice storms, or the weight of snow, all being more of a mechanical issue. We do not have those problems here for the most part nor do we face "windchill" issues, but this latter issue is the one I was referring to. Especially on the twigs and branches of smaller plants, freezing winds can cause twig death. When growing a maple in a borderline zone, or even out of zone, many people learn to live with some winter kill from this type of damage. It does not sound like you will face this problem.
I am facing the same dilemma as I planted a number of newly grafted Japanese maples in pots last spring. I recently replanted most of them in larger pots (or in the ground), so they have more soil protecting the roots. So far, I have been leaving them outdoors but the lowest temperatures have only been in the high 20s. It's supposed to dip down to the lower 20s this week, and I'm hoping my maples will be OK. Since I live in NC, we seldom get temperatures lower than the mid-teens, although lows from 0 to 10 occur occasionally. My garage is unheated with no windows. It is probably a good 10-15 degrees warmer than outside temperatures at night, but also gets hotter during the days -- particularly when it is sunny and warm. It seems like a warm spell could induce the maples to leaf out sooner in spring or late winter. Another alternative would be to simply "heel in" your maples in pots. That is, sink the pots in the ground to a level where the roots are protected. I think that would protect the pots from freeze damage as well, but not totally sure.
You really just need to worry about the 15 and below temps. As soon as we get out of that mode here, I bring everything out of the unheated garage. I've never had a premature leaf break. I move my trees inside when I hear a forecast with 15, just to be safe, and leave them there until it gets back to consistent lows in the 20's. Last year was cold here, I'm hoping this year will be a little milder. I was more concerned about my seeds which were in the garage and probably heated up faster in the spring. I may try something different with them this year.
Kay, Your post has lead me to understand how lucky I am to have the situation I have. Since my garage is well insulated, temps do not fluctuate as dramatically as they do outside. In fact, I can usually delay bud break by a week or two if I leave the trees in the garage since interior temperatures will actually be cooler than exterior temps on warm spring days. I have used a sun box (cold frame) to break rootstock dormancy in late winter. But, like you, I end up shuttling plants around to protect them from frost. My neighbor has a small heated greenhouse that he fires up in March for his vegetable seeds. He usually leases a little shelf space to me for a few of my early spring grafts and they do very, very well in this sheltered environment. He keeps it about 60 at night and 80 or 85 in the daytime. My juvenile acers love it. But, if his heating system were to go down on a cold night, they would probably all be toast. Bryan
Kay, The buds on you japanese maples can still take freezing temperatures during the swelling process. It is actually the new jeuvenille foliage that is most sensitive to frost or a hard freeze. It is not a big issue with the buds as the freezing temps that time of year are very tranisient in many areas. We may hit 28 or 30 deg. F. but it is only for a few hours. Once the leaves are out there a hard freeze can damge the fragile leaf tissue and damage/burn or kill the new foliage. If it is just the buds you are having to worry about, then the tree will mostly manage that. Sensitive varieties that commonly break dormancy first, Corallinum, Beni tsukasa, and some others are quite tender, where my Aratama will be a week or two ahead of them and not blink at the frost. So from that standpoint, you have to know the particular variety you are dealing with. The best way to learn is just to let them have it. Stick them out there and if you are going to be above 25 or 26, forget about it. If you are going to see very low or prolonged low temps, then shelter them. By my saying let them have it, I also imply the use of some common sense. Leave you plants out if you feel the risk is marginal.
[The best way to learn is just to let them have it. Stick them out there and if you are going to be above 25 or 26, forget about it. If you are going to see very low or prolonged low temps, then shelter them. By my saying let them have it, I also imply the use of some common sense. Leave you plants out if you feel the risk is marginal.[/QUOTE] Thanks. See that's the kind of info I need. Just to have an idea of the range of temps that I can subject them to. I always think below freezing. Every year I order more maples and learn more about bringing them in. With living in zone 5, I sort of feel it's an experiment with some cultivars anyway. Our winters usually have days below zero, but in a good year no lower than -10 degrees. I ordered about 10 in the fall, so I'm hoping the poly house will work. A marginal heater might be all I need when March/April roll around, just for those 20 degree snaps. I've wondered about a heating cable that would just keep the temps from dipping too low.
