Growing Japanese Maples: A Guide for Novices (Not Dummies!)
There are literally hundreds of different Japanese maple cultivars, many of which are grown very successfully in many different parts of the country. Choosing the type, color and size of Japanese maple cultivars is not an easy task in itself. Add to that, choosing those cultivars best for your area and individual situation, it becomes even more daunting for the novice. Some cultivars can be easily grown in many areas. Others are not recommended for certain other areas, while a very few are really only for very specific Japanese maple “happy” areas unless kept in containers. Many folks living in good growing zones will use different techniques than you will use due to the different environmental conditions where they are. This makes the choosing and growing of these beautiful trees successfully seem challenging. I guarantee it is do-able with the correct and best advice. This section should impart to you a general idea of how best to grow Japanese Maples in colder zones with a good chance of having a successful and pleasurable experience.
This section should be used as a guideline only. It should NOT be seen as in any way as “scientific”. This information comes only from my experiences, observations, readings, and conversations with others in this field. Any info contained herein is specific for Central Illinois unless otherwise noted.
There are several other good sources of knowledge for the novice that may or may not be of additional help. The best and most reliable source is J. D. Vertrees book titled simply Japanese Maples. Although J. D. has long “passed on”, this book, in its several revised additions, lives on as the best reference material available for a more scientific overview of these great trees. You can also check out the Japanese Maple forums at Dave’s Garden (no relation), The Garden Web, and the UCB forums. You can learn much from all of these places. But there is very little, if any, real scientific knowledge or double blind studies on Japanese Maples as it relates to many of the cultural differences you will deal with. Also be aware that when you enter these forums you will get a lot of strong opinions some of which are much too “fussy” and at times “loud”.
Ultimately buying a Japanese maple from Davidsans, and using our expert advice to do so, will be the best way to achieve maximum success in not so Japanese-maple-friendly areas. Buying from Davidsans will be the best decision concerning these exceptional trees you will ever make.
If you talk to 100 Japanese maple growers and propagators you will likely get 100 different opinions. Many specific suggestions for growing these trees are “area dependent”. If you live in a Japanese maple-friendly area on either coast you can throw many of my suggestions in the circular file. Conversely if you don’t live in “those” areas, their info may not in the least be relevant to you in your area. There are, though, many hard and fast truths that apply to everywhere and those will be specified in this discussion. It is my firm belief that too many folks take their care of these cultivars a bit too seriously to the point of near neurosis, even though many of these folks are from areas where these trees can be grown as easily as weeds. We may have to work a little more to achieve a success rate remotely close to our easy-growing friends, but we shouldn’t’t get too wacky worrying about these cultivars. When you get right down to it, even in these not-so-Japanese maple-friendly parts you will find most of these cultivars just aren’t that picky, and many are surprisingly easy to grow. You might not have the “grow-like-weeds” factor going for you and you won’t likely achieve the size and eye-opening beauty with certain pickier cultivars as your coastal brothers and sisters do. But literally hundreds of Japanese maple cultivars can be grown here with their own special charm.
I have tried in this section to put in just the basics to help you be successful. I have written this out of my total love and addiction to this species which may be a bit too much information (TMI) for some. So take what you want from what I have written here.
You must first carefully unpack the tree. Be careful to not break the trunk or otherwise damage it. You may lose a small branch here and there and/or a few leaves. This happens on occasion when shipping trees, and will not hurt the tree or even be noticeable. Your tree will grow many more branches and leaves. Just prune it with clean trimmer if it is ragged.
If you receive a Japanese maple potted with just buds and no leaves in a dormant state, take it out of the plastic bag and keep it watered, but not too wet. You can temporarily keep it in the pot it came in, plant it in a new pot, or plant it out in the yard. But be careful; if your tree leafs-out in early spring warm weather and then gets hit with freezing or near freezing temperatures, you may have to cover it with a tarp or bring it inside if it’s in a pot. It could lose all its early leaves, be severely damaged or even die from the cold snap. So check out the average frost and freeze dates and pay attention to the weather reports!
If you receive a Japanese maple as a semi bare root tree without leaves in a dormant state do as above but it can be permanently planted out or potted immediately. Again, be careful to watch for weather hazards!
In addition to the above instructions, you must also take additional steps in caring for your tree. It is never advisable to immediately plant it out in the yard at this time. It is best keep it in a pot (either the original pot or your new one) in a shaded area ONLY! You should keep it in a shaded area for at least two to three weeks. DO NOT place in full sun!!! Gradually, after that period, you can move it to a partly sunny and eventually to where you want it. “Why?” you say??? Because most growers including Davidsan’s will send you trees that have been under shade cloth which is by definition, “shady”. Putting the tree immediately into bright sun will fry it as I have learned the hard way – several times. This gradual adjustment to sun also allows the plant to gently get used to your local humidity and other cultural and weather conditions. After that most important period of adjustment you can plant it out.
If you receive a Japanese maple as a semi bare root tree with leaves of course you will need to put it in a pot with potting soil or your soil mix and acclimate as above before planting out or placing pot in its desired spot. If you can’t pot it right away be sure to water the bag thoroughly, keep the top closed to keep roots damp and pop a drainage hole or two in the bottom of bag so the roots don’t sit in water. Don’t leave it un-potted for more than 3-4 days and keep it in cool darkened place. DO NOT PLACE IN SUN!! Follow the same acclimation period as above when you get it potted.
If you absolutely have to plant your tree in the ground right away, you will just have to live with the fact that the leaves may fry the first year unless it’s planted in shade only. Even then you may have some damage from the transplantation. But if it does crisp up or otherwise be affected, it will likely do no harm other than aesthetically and will likely shoot out secondary leaves later in summer, and look great the following spring.
The location for placement of any Japanese maple cultivars is one of the most important considerations you have to make. Generally speaking Japanese maple roots will not damage drainage pipes or foundations but you should always be forward thinking by considering the eventual size of your newly purchased cultivars This is often difficult to do but sometimes these trees actually do grow like weeds and get VERY large depending on the specific cultivars Here in Central IL, this is not so much a consideration. The heights listed on this site are on the short side because growth here is generally much slower than in milder climates due to shorter growing season, winter dieback and other factors. If you live elsewhere take my size figures with a grain of salt. But be careful not to plant too closely to buildings, other trees, sidewalks, driveways and other permanent obstacles. Although Japanese maples have generally shallow root systems compared to many larger shade trees, if you wrongly site it and need to move it 5 or 6 years down the road, it is a really big job with a good chance of damaging the tree and maybe even the obstacle it is too close to. If you don’t move it, you will probably have to trim your tree to shapes that are not pleasing (read: absurdly ugly or silly or stupid looking). Just keep in mind that your new Japanese maple WILL grow, so plant it a generous distance from such obstacles.
If you must have your Japanese maple close to a building or other object, you could just keep it a container permanently. That will allow for easy movement and even keep the tree smaller than if it were planted out. If properly up sized (re-potted in increasingly larger pots) and periodically root pruned, Japanese maples can be kept happy in containers virtually forever. If you have space constraints and REALLY want to plant it out near a building, use a dwarf tree or small dissectum. You should be aware that the words “dwarf” and “small” are relative terms and can have various size determinants. Although generally less than 5 or 6 feet, the tree may really “like” your placement and may get much bigger. Also some dwarfs and dissectum are relatively short, but can get very wide. All of this should be factored in when planting in ground close to just about anything. My best advise for planting near houses, sidewalks, other trees etc. is simply DON’T DO IT.
This is a subject everyone is interested in but there is little scientific information available. Most Japanese maples will live planted out in zones 5b and warmer (some can be grown in 5a and colder). But the zones are changing and the new zone chart based on the last 20+ years (Global Warming) has moved my area from 5b to 6a, based on temps during that period. Zone assignments should be taken with a grain of salt. You might have good luck with a certain cultivars, but 5 miles away a good buddy of yours won’t. This is true even though he/she is using the same exact cultivation techniques and placement as you are. And your neighbor’s yard or even one part of your yard may be warmer and more Japanese maple friendly. These are called Micro-climates, or as in the case of within your yard or neighborhood I call them “mini-micro climates”. Wind protection from a fence, being higher up, such as on a hill, being close to large water bodies, snow fall acting as insulation… All these factors can cause microclimates that allow one person in colder zones, or colder areas within warmer zones, to be more successful while another has less success. I have marked several cultivars that seem to be particularly hardy for me as well as other growers. These should be given first priority by those “colder” folks. Most other cultivars I have listed on the site will also likely do just fine too. If you are a bit gun shy about spending $$ on something that is not guaranteed, pick those that are listed as very hardy or just keep it containerized, which really is no big deal as you will see below.
Also note that, as happened in 2007, if we have another prolonged warm March period, allowing Japanese maples to fully leaf out, followed by a prolonged teen and twenty degree period in April, all bets are off for survival of many Japanese maples, period. This very odd occurrence caused extreme damage and destruction (and a boon for many Japanese maple sellers with many needing to replace dead trees !) to many of these trees as far south as Atlanta, and from Texas to the east coast. This unusual occurrence actually did more damage the farther south you went in zones 6 and 7+. Although many trees survived and re-leafed, many others had severe bark damage from flowing sap that froze and popped the bark off causing eventual death. I had some losses here, but 90 miles south, in St. Louis, it was devastating. Ironically, Chicago and other zone 5a areas in southern Wisconsin that are generally less conducive to growing Japanese maples and more apt to get late frosts and freezes, were untouched and had a great growing year. This was considered a once in (a lifetime) 50 -100 year happening. But with changing weather patterns, global warming, etc who knows? As they say, “the only thing certain in life is death and taxes”. So this information on hardiness should also be prefaced with “depending on having normal weather conditions for your area”. Also remember some Jm’s bud earlier than others . This will be of no help in an extreme situation like we had in ‘07, but under normal spring conditions it can make a BIG differnce . If a cultivar has an “early” budding moniker and you live in areas that often get late frosts especially areas where warm periods are followed by an occasional frost period you best stay clear of that cultivar.
I will make this straight-forward statement here, that you will also see on many Japanese maple related sites. The best possible setting for any Japanese maple is: MORNING SUN AND AFTERNOON SHADE or ALL DAY LIGHTLY FILTERED SUN. Even plants that do okay in full sun or a lot of shade will benefit from this placement no matter where you live (the only exception are a very few extremely sun sensitive cultivars that should be in deep shade). They will generally have less leaf burn and better color throughout the growing season in this preferred placement. Sometimes, though, this placement is not possible. You may, like me, run out of these perfect areas quickly depending on the size and make up of your yard and how many Japanese maples you eventually collect. There is a good chance you will quickly acquire many Japanese maples from your eventual addition to this beautiful tree. (And you will get addicted!). If you run out of these prime areas, you will need to pick those cultivars I have labeled okay for sun or shade whichever is your situation. By mid-summer even the most sun-worthy cultivars will be partially or fully burnt depending on how hot the summer and the age of the tree (an older tree will help mitigate this). If you have all deep shade you will get less and perhaps atypical growth. Most Japanese maples though will do fine in moderate shade but will not color at all or only lightly color. So choose your poison: several months of great beauty followed by a few months of a sort of shaggy looking plant with the less fall color; or season long semi-beauty with great fall color.
All Japanese maples need a period of cold winter dormancy. That is one reason they are NOT house plants!! It is also a reason many won’t grow as well (or at all!) where it is really warm all year long with no cold dormancy period (southern Florida etc). Even though they need the colder dormancy period, almost all cultivars will benefit from having a bit of winter protection. Blockage from winds helps give the plant some protection and helps with containing winter die back. Protection from direct south sun will help prevent the bark from splitting due to excess warming during the day followed by severe cold nights. The sap will begin to run in the heat of day and then literally freeze in the tree and burst the bark.
The most important protection you can give your tree is to mulch it well. You should do so immediately upon planting and continuing for at least the first few years. To put it very bluntly “mulch early and often”. (SEE MULCHING SECTION BELOW.)
For easy winter damage protection you can keep your Japanese maple in a container and place it in a protected place for the winter. You can bring a potted tree into an unheated garage or out-building away from windows (keeping them from direct or indirect sunlight) until spring. But you may have to do “the old in-and-out-shuffle” in spring if you start getting warm days but is still really cold at night, because as your trees may start to break bud in the garage earlier than you want. I prefer this to EVER burying pots or “Christmas wrapping” pots and trees in insulating material etc which I feel is just silly and way too much work. For large containers, you may decide to leave them outside for the winter. Be sure that it is in an area where deer will not go (e.g. near your house) and that will provide protection from cold, wind etc.
I have started leaving larger pots (5 gallon or larger) outside all winter in a protected area or porch (un-buried). My experience with this has been mixed, and sometimes disasterous. I generally think if you are in an area with below 18 degree temps and NO snow cover you will not be happy with the results of leaving pots out exposed!! even leaving larger ones out is dicey . You should do so at your own risk. The chance of damage is compounded if you get allot of rain fall and your pot freezes with waterlogged root system … you will then most likely have a disaster. But at any rate leaving quarts, gallons or even 2 gallons out unprotected is NOT ADVISED EVER even in warmer zones but especially in colder zones. There is just too little dirt for insulation and the root ball is too small. With a larger pot you have more soil protection, and even if you have some root death you have a big enough root ball with enough living roots to make it through the winter, but as i previously said only in warmer winter areas. Bringing pots inside a building and even having to do the “shuffle” is no big deal especially with smaller pots and if you don’t have hundreds like I do. and I now recommend this. Bringing pots into your garage or out-building also saves having to devise critter protection. As I have said, growing Japanese maples should be fun, not arduous so don’t make things any more difficult than you have to or severely micromanage their lives, thus yours but be aware of their special needs in borderline areas.
It is very important to protect your tree from critters even if you think they are not around. Animals can cause severe damage to your Japanese maple trees through the winter until late spring when other sources of critter food become more inviting. Rabbits, deer, mice and other rodents can be a curse. If you only have a few smaller trees, a 24″-36” tall roll of chicken wire tied to 3’ lengths of 1/4″ rebar will do nicely, with both being readily available at most hardware stores . For tools, a pair of cheap tin snips and a hammer (to pound the rebar if the ground is hard) are all you need.
Push or hammer three or four rebar into the ground a foot or two away from the tree in a triangular or square shape. Then wrap wire outside the rebar and cut it at the end point. Twist the ends of the cut wire to connect the beginning of the wire or rebar. Make sure it is pulled tight to the ground and you are DONE. It takes about 3 minute’s per tree MAXIMUM. Larger trees can just have plastic tree guards put on by fall and taken off in spring (be sure to take off in spring, otherwise it may become a breeding ground for insects and fungus. A larger tree is really unlikely to be targeted so at that point no protection is probably needed, unless you REALLY have a severe deer overpopulation problem. Then you just have to build a giant wall around your yard…
There are two parts to this section: one section concerning “container” cultivation, and another section on “in the ground” cultivation. Both are vastly different and have their own plus and minuses. In the past, I was always an in-the-ground person. It just seemed unnatural to plant trees in containers. Plus I had several acres of land which made it seem doubly insane for me, at least in my mind. I no longer have this predisposition and not just for Japanese maples but many species that can be easily can be cultivated in containers and it has its benefits!
I think this topic has the most divergent opinions. I personally will say for the most part many grower/collectors spend WAY too much time in a very persnickety way on this topic. Basically you want a medium that drains well and does not dry out too fast. Out west they rave about soil-less bark mixtures of pine fine bark chunks, “Turface” and very specific mixtures… 30 % of this, 10 % of that, etcetera. Some even go to the extreme of sterilizing their mixture and screening it to different sizes. This will not hurt the tree and I will not get into any discussion whether it helps or to what minor extent. But I do feel it is a bit “much”. In addition most spurn using any pre mix soil or anything with time release fertilizer. I feel the only really important requirement with soil is to use a well draining mixture. Japanese maples DO NOT like wet feet PERIOD!
What I have found true is the following. If you like to mix your own, use several different barks types/sizes along with Turface or turkey grit and a good % of just about any potting soil (YES, I said POTTING SOIL). Mix it all together on a tarp and use whatever % you like, that seems have the right porosity and feel to you. The potting soil will give the mixture much needed body, and the ability to hold water, so that you don’t have to water daily. But at the same time you have a mix that drains “adequately”. If you don’t want to mix your own “home brew” you can probably get away with using only potting soil although I would highly recommend adding turkey/chicken grit, Turface or at least Perlite to help it drain. NEVER put rocks or pottery in the bottom of pot. If you follow this recipe, the type of potting soil or specific mixing agenda is pretty irrelevant. Advise for one part of the country might not be recommended where you live and it’s all a personal matter anyway, as long as it drains well .A bag of potting soil with slow release 3-6 or even 9 month fertilizer is fine (I will talk about fertilizer next.) But I do agree with those persnickety folks that you should NOT EVER get a soil product that has water retaining gel or beads in it. It is always best to let the soil dry out a bit between watering which is not possible with that water retention “crap”. That one is a no-no so carefully read the soil contents on the bag and if it has these water retaining additives, walk on by. I have come to also agree with others that using a potting soil containing mostly peat is also not advised. In addition to making it harder for water to soak in, it does a poor job of water retention, making it necessary to water unacceptably frequently. I use Pro Mix BRK / Micorise PRO in my mix. It does have some peat, but also bark and Micorise which promotes root growth. Pro Mix BRK seems to be a good addition to any mix and probably could be used by itself with the mere addition of turkey grit for a bit of extra porosity.
The two rules of thumb that most folks agree with are:
Adding a bit of extra fertilizer as a top dress along with what’s in your store-bought soil is okay from what I have experienced. Just keep it minimal. Many folks use a rose fertilizer which has low “N”, some use Osmocote products. I use Scotts Top Coat with Minors; these minors many feel are beneficial. Time release is fine and even if it has a high N #, it likely will not do harm. Just go with the lowest dosage amounts on the package. Also don’t fertilize (or heavily water) a distressed plant even if you think it will help, as many sorry folks do. It will do the exact opposite in most cases sending your precious tree quite quickly to its speedy demise. You will be in reality be “loving it to death”!!! Also never fertilize late in the season. This can often cause unnaturally late growth that doesn’t have time to harden off before damaging cold weather, thus causing severe winter die back or (rarely) death from severe stress. Even though time release can do this automatically I have found it is not in large enough quantities to do harm. Also remember that a lot of salts and other byproducts from fertilizers can build up over the years of application, and you should plan on completely repotting your tree(s) every few years even if size-wise it doesn’t seem necessary. You could use an organic fertilizer to keep the salts and other additives to a minimum. But many of these, although they are good products, are pretty expensive and often foul smelling, messy and I don’t think there is much benefit to them. But in all fairness many people use them, so this is your choice.
Obviously, watering is crucial to plant growth and survival. I really don’t have a very specific answer for you. A lot of it is learning by experience. Mainly, I suggest to water well and let it dry out between watering. DO NOT water every day. It would be difficult to drown a potted Japanese maple with one good soaking, but watering too often can do big damage rather quickly. “Wet feet” can cause deadly root rot.
If you have rain twice a week and it’s not 100 degrees you may not need to water much or at all with larger pots. Always be watchful of two gallon or smaller pots as they dry out fast, especially in hot weather. And a tree in part shade may do fine with much less watering. I wouldn’t be prodded by the persnickety folks into putting the plant on a drip irrigation system, using soil water content meters, using only de-chlorinated water, or very slow drip watering over hours or any other such malarkey. Just water the damn thing when needed. Use your hose, use it at high blast or low and make sure you water from inside (at tree base) outward and thoroughly. It’s easy to check the soil often with your plain old finger to see if it is dry. And remember: don’t water a sick or distressed plant unless the soil is totally dry. If it is a disease you will just be adding add wet feet/root rot to its problems. If it’s not disease but rather wet feet you will just make them wetter! Watering is like many things in life, you must just get into a routine, sense the ebbs and flow, and with experience you will know when its time to give it a drink.
The size of the pot should be large enough to give the roots space to grow, but not so big as to overwhelm it. If the pot is a lot larger than the root ball, the roots won’t be able to soak up all the water. This causes the soil to stay too wet, and can cause problems with root rot or fungus growth. Conversely, using too small of pot is never a good idea either. In addition to causing you to embark on a rigorous watering regimen, it also can cause the tree to be root bound sometimes to the point of it damaging or killing the tree. I personally use a larger pot (but not a humongous one) so I can minimize my watering and constant up sizing while not causing any undo harm to the tree. Just about any container with a drainage hole will do. Drainage is so important that you should never put a saucer underneath or use a pot without drainage holes. Placing rocks or pottery in bottom of pot is also a bad idea since it will keep it from draining too. When you transplant a Japanese maple, keep the trunk at the same soil level it was in the previous pot, being sure the graft is above the soil line. NEVER plant the tree with the graft below the soil. The graft is usually an obvious lump or a bump on the trunk. A graft line can also show up as a change in size or color of the trunk. Be sure to scarify the root ball to loosen it if it seems a bit root bound or tight, and trim any broken or encircling roots. Plastic, ceramic or cedar will do just fine. Cedar and ceramic may cause you to have to break the pot open to upsize it if the root ball gets too big. This is especially true with cedar as the roots can actually grow through the pot at the bottom and sides. But with cedar you get a sort of air root pruning that Japanese maple’s seem to love. I personally love their look and have good success with them. Putting a plastic pot inside a ceramic or cedar is ok as long as BOTH pots have drainage.
The overall benefits of containers are:
The downsides:
At first, in ground planting was my preferred method, but that has changed. I still find it SO VERY appealing to have phenomenal yard trees of varying sizes “naturally” blending in as well as ingratiating the area with spectacular color and form.
There are several factors important if you wish to “plant your Japanese maple out” in addition to location and protection in winter and summer as I have already stated.
You can plant Japanese maples at any time of the year. The best time is early spring to early summer. This gives the tree one whole growing season to set out roots and get acclimated to your area. From my experiences I have found the worst times are during the mid summer and fall.
Mid summer planting, except in exceedingly brutally hot areas, is ok but JM must be babied a bit more and acclimated to your environment… If I had to choose i would do spring but if you are careful you will have no problems with mid summer plantings . If you plant in mid summer do so in the late evening, and water well, never in the heat of day. Be sure to give it a bit of extra winter mulching and protection. And remember most Jm’s are grown under shade cloth and if at all possible pot them up and gradually move them from complete shade to your planting area over a two week spread . Otherwise your tree may denude upon planting . It will 99% of the time grow new leaves but it does put extra stress on the tree and of course it will not look great til it re-leafs.
Fall planting is a great idea for most trees in this area, many considering it the best time to plant trees. Just within the last few years nurseries have been pushing fall sales for this reason. It gives nurseries a second season of sales and the customer an ideal planting time. But with Japanese maples it can cause some sometimes serious problems for northern growers only . Most of the problems come from late fall growth, and / or the failure to harden off the tree before planting (tree NOT being totally dormant). If you’re your tree is in fact completely dormant and properly mulched and protected, it probably can be successfully planted in fall. The problem is telling whether it is totally dormant. This is especially true with trees purchased from the coasts and those kept in cold frames or greenhouses. What may “look” dormant ( no leaves or dried up leaves) may not actually be dormant or possibly just have gone into dormancy. You plant it out and get severe weather and BAM! My experiences have been that most trees planted in fall survive no matter what. But the real test is what % of those Japanese maples planted in fall, compared to spring make it. From my experiences , the difference is not large as far as numbers of dead trees. But the % of deaths between spring and fall planted Japanese maple is higher. More fall planted Japanese maples succumb from fall planting than those planted in spring. My conclusion is DON’T fall plant you are on a latitude above St. Louis, unless you are in a micro climate or an area where it does not get in single digits for and extended period of time . Even if you live in a very cold area you can still buy your tree and keep it potted in the garage over winter and them get an early start next spring planting it out still dormant which can be the best time to plant out and often finding dormant trees in spring is difficult.
For those in southern or more moderate areas …fall is a great time to plant Jm’s and you should have no compunction about doing so!! But your selection will be most always less in fall.
Firstly you should choose a well draining area with no clay, rock, or muck. Muck will leave it constantly wet and kill the tree by root rot or fungus. Clay and rock below a certain soil level will make water pond at bottom and create a constantly wet environment. Always plant at the level it was in a container or as it was previously stated at a level at or slightly above where it was planted before you got it. If roots show on top it is ok, many traditional Japanese growers grow there trees that way and have done so for centuries. Remember my statements on size and plant the tree with growth in mind. And finally, try to open up any root bound root ball especially paying attention to roots encircling the tree. This, on some older not recently repotted trees, is VERY difficult. I think you should do what you can but DON’T hack the roots up totally, you may loose the tree. As always clean all instruments before and after using with alcohol. I use a pump bottle of alcohol based hand sanitizer which works well.
One area of disagreement I have with the Japanese maple savants is with amending soil. These Japanese maple “experts” state, amending is NEVER necessary, advisable, or wise. For the most part I stand squarely with those “nyet” (naysayer) folks. But think it is pure folly to “never say never”. Yes, it is not advisable because it can cause drainage and ponding problems. And your tree will eventually grow out of it into crappy soil eventually causing more problems. But ultimately I must disagree with the finality of this aversion. As I see it, the bottom line is, if you want to plant a Japanese maple and your soil is muck, rock or clay or whatever, you “gots to do what you gots to do”. Be sure when amending to do so with rather large area and do so deeply. Yes is a lot of work BUT if you want your Japanese maple to grow and you love them … that’s what you “gots” to do. Telling someone NOT to amend when nothing, especially a Japanese maple, will ever successfully grow in their yard where they want to have one, is idiocy. Yes amending is not advisable or necessary for most folks. But as a last resort only an ignorant person would say no!!
Everyone DOES agree that mulching is absolutely the most important part of in ground planting!! It protects the tree during the winter but even more important, it keeps it moist in summer. A little extra mulching expense is worth its weight in sweat, because you will need to water much less especially the first year and it gives you a bit of a safeguard if you forget to a time or two. I use only cedar bark mulch which keeps the bugs away and is really a good water keeper. You can use whatever mulch you like. Do as large as area as you wish but keep it about 4 – 6” from trunk (Any further away, no matter what other overly anal growers say, is not necessary). And apply mulch least 3-6 inches deep.
Fertilizing is the same as with containers, spring only, and same type of fertilizer, and never too much. You should know that if you have rich soil you may want to forgo fertilizing altogether. It can cause excessive shaggy growth which you may get anyway with some cultivars in nitrogen rich soil, In all but the most fertilizer starved areas it is probably never necessary but will never hurt in moderation and at the proper time It may also be necessary in areas that you have planted a Japanese maple where nutrients are being used by these trees and long rooted plants and growth of your tree seems stunted or color is weird, then by all means fertilize as above, but gingerly.
Watering is important the first and possibly second year only. It may also be necessary in future years if you have a drought, live in a very dry area or your tree is VERY small (which shouldn’t be the case with a Davidsan Japanese maple). During the first year, water your tree at least once a week (or more if it is really hot) unless it is extremely rainy. If it rains twice a week, watering these young, newly planted trees may be not unnecessary. Just periodically and consistently check the soil moisture by pulling back the mulch and digging down a bit with your finger. Obviously, the hotter and dryer your weather and climate is, the more you need to water the first year and second.
The overall benefits of in ground planting:
The downsides:
I have already covered a lot on continuing care in previous sections. What is left is a discussion on pruning the tree, both with potted and in ground planted Japanese maples I also think it is valuable to discuss staking of all Japanese maples especially when young.
Pruning is a touchy subject with me. I really like to see all trees especially Japanese maple’s go au natural. Many Japanese maple’s also will kind of self-prune especially dissectums. Most dwarfs will never need pruning or very little. Others really may never need it and look wonderful. This is all a very personal matter and best left up to your personal preference. I have found that some trees have a lot of schizophrenic growth especially here with our fertile high Nitrogen, jet-black soil in central Illinois. (I personally have never fertilized any of my in-ground trees.) An example of this is my Oriodono nishiki. It grew fast and furious and, after three years, looked like crap (to me). It had no shape, no grace and no character. I have heard similar complaints from other people on this cultivar especially. Trimming it rather severely really helped to give it shape, form and dignity. I was surprisingly pleased with the result and happy that I took this step.
Some trees will become bushes if not trimmed (not that there is anything wrong with that), but if you want to have a more upright tree or one that has one single stem, you can trim it as desired. Other trees may be nicely upright but have a lot of low growth. It probably will look better if the low branches are removed so that you will have a tree with a trunk. NOTE: If you do this with dissectums you will likely get a mushroom-shaped tree with a possibly unsightly trunk where the graft area is. This is especially true if it is high grafted (see aforementioned statement on “unsightly” graft areas). The graft joint will, probably, in the future become invisible, but you will still be stuck with an umbrella-shaped tree that may not look that great. Generally, a dissectum looks better and more natural (to me) with at least some branches on its trunk.
All trimming should be done in very late fall, winter, very early spring or mid-summer (as these are low to no growth periods) It is not advisable to trim branches during the high growth periods of late spring, early and late summer or early fall. I personally have never had a problem trimming at any time but others swear by this and it does make sense, since you can loose a lot of sap during those high growth periods and have some increased chance of disease or insects getting into the wound. But I do believe this is another overstated “rule” from excessive micro-managing.
That all being said, if you have a branch that is broken, dead or dying, you can cut it off just about whenever you like (and you’d best do so) with little chance of hurting the tree. Sometimes you just don’t have a choice when you might have to do some trimming. Always use a good sharp clipper like a Felco brand hand trimmer. Don’t leave stumps (cut as close to trunk or forked branch as possible) and clean the blade with alcohol before and after cutting any diseased, dead or otherwise damaged branch, and definitely clean your clippers in between trees. DO NOT EVER use any sealer. Sealing is not thought to be acceptable for use on any tree wound by most current “experts”. Let the cut heal itself. Coating with any sealer can seal in problems, or create more problems, and is at minimum a waste of time.
Never let someone unfamiliar with Japanese maples trim your tree. Never let anyone trim who is “scissor hands happy. If you hire someone to trim your tree, be sure to go over with them what they plan to do. I have repeatedly heard horror stories about allowing or hiring folks to prune Japanese maples that have no prior experience with these trees or that are overly scissor – happy. This scenario usually doesn’t end well. So be careful. You should know never to top any tree especially a Japanese maple.
Staking is a subject that has not been covered well by most growers. Staking is often necessary with young upright trees, and also trees that get a lot of wind and are tall and spindly. A stake can be useful in shaping the tree without trimming. Sometimes you may want a single leader tree but you have several “semi leaders”. Picking one and staking it straight can accomplish this, without having to hack up your tree. Staking a Dissectum can be helpful in both shaping the tree in gnarly cool angles, graceful arcs or upright branches. It can give many dissectums a more upright appearance. Most Davidsans dissectums have low grafts. Staking a low grafted dissectum will keep the tree from growing horizontally and becoming a ground cover, or low bush, instead of a tree. It’s really kind of cool; you are designing your very own tree without ever cutting or mangling it. Just gently shape to your tastes while still keeping it looking natural. You can use two or more stakes to shape the tree. Use bamboo stakes and tie the branches in the directions you want them to go. In a couple of years it probably won’t need staking any more. Use the green stretchy hand tie tree plastic non-sticky tape available at most hardware or home improvement stores. The ½” width is easier to use than the 1” and is usually adequate. Tie snugly with the knot on the stake, not the tree. When training a potted tree, use a thinner stake that is not much taller than the plant. Remember, you are using a well draining loose soil .If the stake is tall, heavy and/or too thick, it could come easily get pulled over by wind or the weight of the tree, or come completely out of the soil, pulling the tree or limbs over at an extreme angle or the tree itself right out of the pot. In general you won’t hurt the roots with the stake, just make sure to do so gently and not to force it in through them. Always use tree tie tape or any flexible non stick tree tape .. don’t use bread ties or anything with wire it will girdle the tree .. you can use those rubber tree tire like holders but they are a bit of over kill and ugly . Remember most Jms are very flexible and you can stake almost all but the really stiff ones like Green Cascade or really fragile ones like many dwarfs which will just crack the branched off if pulled to tightly.. just keep your stake close and use one that is sized right, you can stake a branch or a min stem or trunk . You can also stake in pots but remember a smaller stake usually works better than a larger one in pots .. Finally staking really depends on the JM if it is NOT stiff or fragile it can be easily and safely done
Bonsai
Choosing JM Bonsai cultivars For the Midwest and elsewhere
Firstly, I am not an expert on Bonsai in fact i do not have time to work with JMs on that level. I do know that many Japanese Maples especially dwarf cultivars that davidsans specializes in make excellent bonsai and are many dwarf cultivar make classic bonsai candidates. I also know the following:
Most Bonsai folks don’t like grafted trees because of the damage to the trunk during the process and the fact many trees are grafted high . Most grafts over time heal to become virtually invisible…In fact older planted out trees show no graft marks unless the graft is crappy, the graft is very high on trunk, or the root stock and scion are different colors ( IE: red/green) Most JM’s are grafted on green Acer Palmatum so as long as you get a green trunk tree you are OK and many bonsai-able dwarfs are green trunked . Most growers DO NOT match root stock and tree because it is SO time consuming and red Acer Palmatum root stock is much more pricey. Many Bonsai folks just buy bastardized seed grown cultivars from unethical sellers using the name of the mother tree They blindly buy these trees not knowing seed grown trees are not true to mother plant and what they have is just a nice tree not necessarily that specified cultivar . There is nothing wrong with that from a buyers point of view ( as long as they know they realize they are NOT getting a guaranteed specific cultivar) but it is definitely unethical for the seller. And since they are not reproducing the tree, it is Kosher just not accurate. Other folks buy hormone rooted trees but most JM cultivars don’t root at all or die shortly after rooting . The best way is air layering but this is so time consuming I doubt 1% of trees sold as such have been reproduced as such .. Air layering is a good way to propagate and is a form of rooting that seems to work and the tree stays healthy…but good luck finding one . In addition unbless you personally know the grower you will never know if it was actually air layered or just a bastardized seed grown tree . Budding is another way to safely reproduce the tree but still the root stock must be cut off above bud creating similar trunk damage. In reality if you want to Bonsai a lets say Koto hime your best bet is to buy a low grafted tree done by a good grafter.
I think the “root” of the problem is most Bonsai folks need to “ZEN” out a bit and understand Bonsai takes years …Its a process not an end product… most Bonsai folks seem just too Americanized wanting an immediate Bonsai . The reality is most Davidsan dwarfs will make great bonsai trees but the graft may show for a couple of years. If you ask , Davidsan can personally pick out trees that look the best for bonsai and have the best low grafts.
At Davidsans the overwhelming majority of trees have very nice grafts 2-4″ above soil line . The trees i personally graft are often grafted at 1″.