Hi, I am a relatively new participant in the world wide web, but I am an experienced grower of Acer palmatum, japonicum and shirasawanum in the Northwest - SWWashington to be specific. I often receive inquiries about the hardiness of these wonderful trees. I have read J.D. Vertrees and other scholars that report plant demise when the roots reach 16 degrees F. I have shipped maples to collectors in Canada and the Northeast who have developed a program for wintering over their maples. So, what I am looking for is feedback from maple collectors and growers that have figured out how to winter over their trees. Is it correct for me to state on my website, as other nurseries have done, that Japanese maples live in zones 5 through 9? Can they take the heat? and what about really cold climates, should people plant in a pot and move the maple into the garage for the winter or is it OK to wrap the trunk of the tree and mulch the roots. I think this is a great forum for information and all of your advise and comments are appreciated. Thanks, Sam
Sam, There is a tool you can use if you go back in and edit your post to move this thread out the to main forum--you inadvertently posted it in the photo gallery. I am in zone 7 or 7b, which would be pretty ideal for most Acers by the micorclimate in the Rogue Valley is hot and dry. I won't labor about how the heat causes problems, but it does. I am best to buy maples that have acclimated or tolerated some california heat than I am to buy from NW Oregon or SW Washinton. I will also do better with the field grown plants out of the Salem area that have seen full sun. I have hundreds of maples, mostly in containers, and some do better than others. In containers the stress will cause diseases in the plant like verticillium and tight bark to cause some real problems. So, for my hot dry climate, the larger the plant the better and in the ground is better than in a container. Anyway, it can be done here as it is in the valleys of California all the way to LA and even in Australia, but we have some unique challenges. If we get real scorch we can lose wood on our plants here with or without dieseas--disease just makes it worse. I overwinter everything outside and have done so for 5 years. From one gallons to 25 gallons. We will drop to 20 and occassionally into the high teens but it is not prolonged and we warm up in the day to the 30's and 40's. My pots often freeze solid, which means some root kill, but I do not worry about it. We rarely have late hard frosts, but we can risk some foliage damage in the spring on occassion. The last killing frost we had down to 15 was 7-8 years ago. When that happens again, I will repost. For me it is heat not cold that is the problem but we can manage it. When you sell to your customers I would be very conservative as maples are not hard to grow, but they are not the easiest of plants either. With extra factors of detriment involved like cold and excessive heat and dryness, growing maples is that much more of a challenge. It is how we get these plants through their adaptation stage (which can last many years) is requires some knowledge and plants of a size that can be shipped (as imagine you will be selling) are not very forgiving. It depends on if you are offering a guarantee. If it arrives healthy and alive, do you wash your hands of it, or are you going to guarantee the plant for a season or more? If you are going to ship a 1-3 year graft and guarantee it then I do not think you can be very liberal in the zone range you are "approving." You will want repeat customers and if you don't think the area they live in will offer success in growing then I would not enter in to the deal.
The issue of guaranteeing your plants is a good point, Mike. Most of my Acer species have come from a nursery, which is nearby and which has the following guarantee: We will provide replacement, refund or credit for any plant not true to name or not growing satisfactorily within the first month after purchase. Our liability will in no case exceed the price of the plant. Of course there is some leeway for regular customers. This nursery also has a retail component; none of the plants are grafted. It would be interesting to know what Frank Byles mail order guarantee was. This nurserys shipping policy takes weather into consideration too, requiring two-day air to certain regions during certain times of the year. Check out the following thread, wherein recommendations for Zone 5 have been enfolding simultaneously: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=15437. Perhaps the best you could do, Sam, would be to make a general statement on hardiness zones and climate challenges, then perhaps note customer reports of certain cultivars successes or failures in certain microclimates or regions?
Laurie and Mike, I really appreciate the comments about growing conditions for Acer palmatum. It is easy to understand why the nursery that sells seedlings would guarantee the maples for a short period of time. There is little cost involved in replacing non-grafted maples. There is retail nursery in my area that guarantees its maples for a year, but this comes with a cost - very expensive trees. I think adding some climate zone information to my website is a good thing for me to do. I just checked my email and I have an order from Arizona. I plan to do more research on growing conditions in the U.S. and include more detailed growing instructions for various climates. Thanks for your input. Sam
Sam, We have been discussing the zone 5 growing of ***. maples on another post. I think it's great that as a grower you are trying to be involved in what is happening to the trees once they leave your nursery. I'll tell you what I think contributes to any successes I have in zone 5: 1- Some cultivars are just more vigorous and adaptable to the cold. There is one grower (can't remember which one) who has a list of zone 5 maples as a link on their site. 2- The quality of the product and how it was shipped is important. I have received mail order plants not packed well with branches broken, branches sticking out of the box, box squashed flat, plants out of the plastic sleeve, all dried up (not just from ebay growers,either, supposedly reputable growers). I have also received (mostly) maples that arrive in perfect, not a branch or leaf missing, condition. These aren't stressed and do better. 3-I have to really pay attention to where I plant the maple as far as soil (not to dry or wet), shelter (not out in the open) from our winter winds, and competition from other trees. 4-In November all trees in the ground are sprayed with Wilt Pruf and wrapped in floating row cover or have a burlap screen to protect them. I do this until they are too large figuring, they have proven they can make it. I think a lot more people would have success overwinter in zone 5 by doing this, but it is a pain and all winter long looks like a bunch of ghosts lurking in my garden. 5-Really have to baby them the first year or two, as far as water. It is so hard to unwrap them in the spring and not have them come back. This still happens even with all those precautions, so I guess number six would be to discourage zone 5 growers from attempting them if they are looking for a no hassle tree to stick in the ground and pay no attention to. I am always amazed at people who do that. Right now I have a friend who has become interested in giving ***. maples a try. She just digs a hole and sticks it in and then asks me why it's dying, but doesn't want to hear why. Some people who buy from you are probably like this. Anyway, I think it's great that you are making the effort. That's the kind of grower I would like to order from :) Kay
Kay, This is really great information. I stumbled upon this site when doing a search about my friend Talon Buchholz and his ghost maples. Anyway, the feedback from maple enthusiasts is wonderful. As a small, small maple nursery I endeavor to sell only maples that will do well for my customers. When I bring my maples to home and garden shows many people ask me for one cultivar and then after asking them questions about location, sun or shade, they end up taking a different one home. I would rather not sell a maple, then to sell one that will not make it. Can you tell me which cultivars you think could make it in zone 5? Also, what about container growing and then moving the pot to the garage for the winter? What are your summers like-hot and dry? I was told that I posted this thread in the photo gallery. I don't know this site yet and I didn't know there were different sections. How do I get to the thread you mentioned where there is more discussion about maples and climate? Hope I am not bugging you too much. LOL Sam
Sam, Neat that you know the Bucholtz. I am really impressed with the hardiness of the ghost series. I left Sister Ghost out last year and it came through with flying colors...no dieback and is doing great this year. This was about a 3 year old and was about 2' high. I am going to leave Grandma Ghost and Purple Ghost out this year. My Purple Ghost was beautiful, but I messed up and put it out too early this year and it suffered some dieback, but I think it will be okay, it's just not as pretty as it was. I make so many errors just out of stupidity and anticipation of spring (sigh...). Rather than repeat what is in the other forum, because there is an east coast grower with some cultivars he's had luck with, I'll paste the forum address here: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=15437 It's called "odds of shin deshojo and katsura in zone 5" Let me know it I can add any more. You can email me privately, too and I'll tell you what I'm growing and how many years I have been growing them. I do container grow, too, some just until they get old enough to try outside and some because it's the only way I can grow them. (Like some dwarfs, etc.) My summers are not terrible, usually. In July we have our driest periods and temps from 80's to 90's. Our biggest problem in summer is water, we have really dry periods. It's been over 3 weeks since we've had a measurable rain. Last year was awful. I had to haul in over 20,000 gals. of water just to keep the trees and shrubs alive. Another problem we have in spring is that we can have periods of 60-70 degrees and then periods of 20 degrees in the same week. Things start to bud out and get zapped. I really want to experiment and get a solid list of maples, including Japanese, Japonicums and others that seem to be able to take it in central Illinois. Kay Dye
I just purchased some cutleaf maples that I will be planting in containers. I live in Phila suburbs (Zone 7) but am concerned about them being in pots for the winter. Is there any special care I need to take? Would I be better off going with as big a pot as possible or putting them in my garage for the real cold stretches? Any advice would be greatly appreciated. They are Seiryu, Filgree and Lion Heart. Thanks. P.S. Any thing you can tell me about growing these plants at all would be helpful as I am a newbie at this. Any links or anything you have will be appreciated.
agentf1 Sorry I didn't respond sooner. Japanese maples must have good drainage and therefore, it is not recommended that you plant your maple in a huge pot. I start with 4" pots at my nursery and then move to 1 gallon containers, a year or 2 later I move to 2 gallons, and then 3 gallons and up. One year I thought why not skip the 2 gallon and go from a 1 gallon to 3 gallon - boy they did not like that. Many rotted away and others that didn't die just didn't grow. I learned a big lesson that year. Smaller maples, with smaller root systems do not want to go into a big pot, even with nursery pots and the large holes in the bottom too much moisture is held. Maples like to have drier roots so you need to plant in a pot that is about 6" in diameter larger than the existing pot or 3" on each side. As to winter, smaller pots can be moved into protected areas. Larger containers can be wrapped with burlap or an old blanket to protect on the coldest days. Good luck. sam
Thanks, I thought a bigger pot would protect it better from the freezing etc. Can I go from the 4" pots to like a 2 1/2 gallon pot? I want something that is half descent in size so I can throw a few things around them next spring. The pots I have are like 12" tall by 9" wide. I will be using some Miracle Grow garden soil mixed with the Miracle Grow potting soil (more peaty) and figured I would throw some foam peanuts or stones in the bottom for drainage.
No you should not go from a 4" pot to a 2gal or larger container. Follow Sam's advice. Todays 4" pots are 2 years or more from being solid one gallon plants. A 4" pot should go into a 1gal for 1-2 full seasons depending on how well you are developing your root systems. Then, a weaker growing plant might go into a 2 or 3gal and a strong grower into a 3 or 5gal squat. If you use a very light mix you can use the larger of the container sizes. You will not get a measurable increase in root insulation by using a 2-3gal can over a 1gal can. What you can do is put your 1gal in a 5-7gal and then fill the air space between the two pots with an insulating material--even soil. You will also want to make sure the pots are moist as a dry pot that freezes will have a much greater amount of root damage as having the pot moist will insulate the roots some. There is still some root kill, but it may not be significant or have a visible impact on plant growth. I overwinter all pots outside uninsulated and they do freeze solid. The extent of the low temps is usually down to the mid to low 20's on the worst night, but we have warming in the day. Most night don't drop much below 28. When you start to talk about prolonged temps near or below 25 with container maples you will risk losing younger ones. In the 15-17 degree range we will start to lose landscape plants and cold winds in combination will begin to freeze branches and tissue.
I am in Phila Suburb of Pa (Zone 7) and occasionally get weather in the teens and even 0 overnight. what do you reccomend I di during this period? I do have a detached garage but it does not get much light at all. I also have a shed but it gets even less light. Do they need a lot of sun in the winter? Would I be better just putting them in the ground? Thanks.
Thank you for asking about Frank Byles guarentees. I guarenteed my trees for one year with no questions asked. I have trees in Miami to Anchorage with repeat orders in both and other areas. When shipping to adverse areas I would call the people to discuss precautions and if a new area I would sometimes test with 2 each palmatums and atropurpureums for 2 to 3 years before cultivars. Some cultivars are more cold hardy and others more heat hardy. Do some research and develope your own list to share with others. I found one year guarentee to be beneficial to our business at little if any net cost.
Does anyone have any thoughts about the winter hardiness of A. pennsylvaticum 'Erythrocladum'? I read someone's comment on one of the forums that the snakebarks aren't as hardy as you would think and often suffer winter damage. Kay Dye
Interesting how cultural techniques vary. For the maples that are to be in pots, I plant them directly in the large pots where they will spend the best of their adult life, and this independently of the size of the pot where the maple was bought (they will one day be root pruned as required). Those that are to be in the ground go directly there, whatever their size (I am in zone 8, almost no snow and I have no deer, rabbit or other maple eating animals). Do I have losses?, well no directly correlated to this. As a matter of fact most of my losses are with maples that are in their nursery pots waiting to be planted (often due to problems already present in the maple from the nursery). Gomero
I am really getting worried by all the comments I have read here. I have a Blood Good that I have had four 3 years. It is about 6 feet tall with a canopy of about 8-10 ft diameter. I have not had any problems with the cold and I am in Iowa borderline zone 4+5 I believe. My biggest problem is I tend to overwater, causing the leaves to curl, looking like they need water. I just found out that however. I sure hope it does not die after all I have read here. I have not done anything for winter protection. We live in the country and I am in the open, but have created a nook for the maple, that must be protecting it some.
If your Bloodgood is doing well don't let us scare you. As you noted - too much watering is the culprit rather than being dry. If your maple has survived three typical Iowa winters then no extra protection should be needed.
I think that is something we all learn the hard way. If you happen to have the perfect climate and perfect soil it will probably work well for you. If, however, you have a heavy clay, bad drainage, inclination to waterlogging etc (which I have) you begin to notice the letters from the Bank manager ..... I have found the comments here to be very interesting and informative Sometimes the simplest comment still opens my eyes after 40 years gardening If you assume that your customers are totally dense and consequently give them all of the information which you believe they will require (which you seem to be intent to do) then I would have thought that all would be well I wish you well
Hi, Gomero- your reply peaked my interest, when you mention that the trees that died on you did so in their original pots. What problems did you encounter in that respect? I also have large containers, but I only planted maples in there that had a significant rootball already, the smaller ones I left in smaller containers. This since the small roots do not like to venture out into soil that is too wet, which is more the case the larger the pot gets (I think that's what mjh means) ... it probably depends on your climate as well. Schusch
Schusch, Mainly Verticillium although also pseudonomas. There is an European supplier, whose name I can give only privately, that supplies diseased trees and buyers are encouraged to buy from him only fully leafed trees. Concerning cultural approaches, of course if your soil is ingrate and tough (and on top of it, the climate rude), you should keep your baby maples in their pots and babysit them. On the other hand placing them as early as possible in their final destination allows for better adaptation, healthier growth and higher drought resistance (and less hassle for the gardener). Gomero
Hi Sam, How are you. I think you know me a pennsylvatica!!!!!!! I have a Sango kaku, among my plethera which is in southwestern PA is in Zone 6/6b, and classed by some as 6b/7.Yet had a unseasonably cold harsh winter in Jan/Feb/ beginning of March. It seems although the books say many things about cultivars climatic capabilities. Supposedly Sango is "slightly" tender to wind and cold, yet this year it has grown 12"+ and is 3 years old and now stands nearly 48". The growth was phenominal. It seemed to thrive very well after below 16F temperatures, and I wonder if deep dormancy is advantageous??, and the resiliance is also phenominal to climatic variation? I ask myself why my sango is doing so well dispite the harsh wind and cold winter months yet my fathers Sango which is 8-9ft adult tree which lives in central Illinois in zone 5b/6 is not doing so well. Possibly it is with variations as such in zoning of plants-eg..temp variations, precipitation, humidity,soil,protected areas, etc and also a slight difference in just half a zone is enough?? I have never grown in the UK dispite the UK being zone 8/9 where I lived until 18 months ago, so I do not know about the other end of the scale. Hardiness to zone 9 I think is pushing it dispite some nurseries and sellers claiming it is hardy. According to Dirr, Dejong, Vertress, etc if you read between the lines-they may live but not thrive in Zone 5 and Zone 9(formed by reading), and ideal zones is 6-7/8 is my hypothesis with the variations. They are adaptable??? to what extent???what affects and allows the ability to adapt to some and not others???genetics/native areas, climatic,etc?? Apparently south western Pa is close to their native Japan. Japan apparently has pretty cold wet and windy winters coming across from China which is habitat to some interesting Acers as well, but warm wet sticky humid summers, and always varing temps, and weather like western PA it can be sunny and hot with 90F temps then 65F with rain or clouds the next day in summer perhaps this cycle and variation is important as well to their survival and thriving???? I pose the questions but I would not be so bold as to assume my hypothesis is correct!!!
Hi Pennsylvanticum. I didn't know you were a contributor to UBC Botanical Garden Forum. I find this website very helpful in verifying which cultivars do well in the colder climate zones. It is very educational and I am trying to add climate zone information to my website. Thanks, Sam
Hi Sam, Yes I was here before but left and came back. It is very informative and there are some really knowledgable people here. A good resource overall if you are interested in trees and plants. I just want to add be careful about being liberal when advising about zones for trees and shrubs. Eg, Not recommended for southern Florida, in actuality all of Florida even northern Florida and Mid to Southern California are too hot for most Acers/ Acer cultivar, these are by enlarge temperate plants. I have seen the wilting, sad trees in peoples gardens and look dreadful, barely clinging to life in Palo Alto, California, classified Zone8b/9+ and Illinois where my example of Sango Kaku which is minimum Zone 6, and the area is actually 5/5b although some recent National Arbour Society classify central Illinois Zone 6, so there are discrepencies to with these average temperature zoning but the limit for most A.palmatum cultivar is Zone 6-8, ideal is Zone 6-7 as is the native habitat of A.palmatum in the valleys and lower slopes of mountains.There are a few which can survive in Zone 5b, extrodinarily one of which is the overrated cultivar "Bloodgood" which is readily available but anyway 5a or below is too cold in winter. The trees may survive? but clinging to life!! because the soil temp even with mulch is just too cold. 8b is the upper limit, and that is pushing the limit as the example of Palo Alto. The heat/humidity and inability to be completly dormant, and many other factors make any species/cultivar inable to compensate and is out of there adaptability range. I personally believe Mother nature did this for a reason. This fact is what helps the native species from invasions, but this is not always the case as you are aware with flower, fauna and animal species. eg. Bluebirds are extremely threatened in the NE because the Brits brought Sparrows because they missed these birds in the 18thC which are not originally native to North America, and are too competative for the native Bluebird species. Talk to you again soon. Kindest Reguards P
There is good information (albeit mostly on British zones) on this link http://www.trebrown.com/hrdzone.html
