How Often Should You Water Japanese Maple Trees in Containers?

DAVIDSAN’S Planting and Care Guide

Growing Japanese Maples: A Guide for Novices

What the heck do I do now? Receiving your Japanese maple tree.

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. You will have more of this with twiggy dwarfs and dissectums but it should not cause concern . If you picked up the tree at my nursery you would likely have that before it got home. Your tree will grow many more branches and leaves. Just prune it with clean trimmer if needed .

If you get a Japanese maple potted with only buds and no leaves, it is dormant. Take it out of the plastic bag and water it, but don’t let it get too wet. You can temporarily plant it in a new pot, or plant it out in the yard. But be careful. If your tree gets new leaves in early spring when it’s warm and then it freezes or gets close to freezing, you may need 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. Check out the average dates of the first frost and freeze and pay attention to the weather! It’s hard to cover trees with tarps. you MUST remove it before it gets much sun or the leaves you saved will be tried . Also, any leaves that touch the tarp will get damaged if it’s not thick enough. Don’t worry too much about this; just wait for the damaged leaves to dry out before taking them off the tree. Jms have secondary buds that will pop up and you will be good to go . Often, it freezes or frosts hard, and if there is a lot of wind, many JMs won’t show any damage. but wait a few days before you celebrate . It looks like it will be damaged after that, especially if it hits after a freeze or heavy frost and then it gets sunny, rainy, or cold again. If a week goes by with no damage, you can smoke or do whatever you want to celebrate.

If you get a Japanese maple as a semi-bare root tree that doesn’t have any leaves and is dormant, follow the steps above. It can be planted outside or in a pot right away, though. 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 should only be kept in a pot in the shade, either the old pot or the new one. This is how it should be kept for one to three weeks. DO NOT put it in full sun!!! After that time, you can move it to a partly sunny spot and then finally where you want it. You might ask, “Why?” Well, most growers, including Davidsan’s, will send you trees that have been in shade cloth, which means they have been “shady.” I have learned the hard way more than once that putting the tree right into the sun will kill it. This slow adaptation to sun also gives the plant time to get used to the humidity and other cultural and weather conditions in its new home. After that most important period of adjustment you can plant it out. If you are going to plant the Jm in a spot with a lot of shade, you can probably plant it out right away. If not, be careful. But if you should screw up and forget this “no no of planting) don’t freak out , 99. When you fry a tree, it will almost always set out its secondary leaves in three weeks or less. So there is usually no permanent damage although you will obviously get less growth and fullness that year.

If you get a Japanese maple as a semi-bare root tree with leaves, like most of Davidsan’s trees, you can plant it right away if it’s early spring or in a very shady spot. But it’s best and safest to always put it in a pot with potting soil or your soil mix and let it get used to its new environment before planting it out or putting the pot where you want it. Since it will only be there for a short time, this can be a quick planting that you don’t have to worry about too much. To keep the roots moist if you can’t pot it right away, make sure to water the bag well and keep the top closed. Also, poke a few holes in the bottom of the 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 have to plant your tree right away, you might have to accept that the leaves might get brown the first year if it’s not put in a spot with a lot of shade. Even then you may have some damage from the transplantation. But if it does crisp up or get hurt in some other way, it probably won’t hurt the plant in any way other than how it looks. It will probably grow new leaves later in the summer that look great. It will really pop the following spring the following spring.

One of the most important things you need to think about is where to put any Japanese maple cultivars. While Japanese maple roots usually don’t damage foundations or drainage pipes, you should always plan ahead and think about how big your newly purchased cultivars will get. This isn’t always easy to do, but depending on the cultivar, these trees can grow like weeds and get VERY big. In Central IL, this isn’t as much of a concern. The site’s listed heights are on the short side because plants grow much more slowly here than in warmer climates because of the shorter growing season, winter die back, and other things. 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. Japanese maples don’t have very deep roots compared to many other large shade trees, but if you put it in the wrong place and then need to move it 5 or 6 years later, it will be a huge job that could hurt both the tree and the thing it is too close to. You might have to trim your tree if you don’t move it. It’s not a big deal, and JM’s trims easily. But if you get too close to an area, you might trim it into shapes that aren’t nice (read: ridiculously stupid, ugly, or silly looking). If you plant too close to a building, especially with dissectums, the back of the tree may not get any sun, so it won’t have any leaves. It will also have a lot of branches that need to be trimmed, and it will eventually grow into a half-circle. Also, if you don’t have gutters or if they get clogged or leak, and your new tree falls into a waterfall, it could drown. So be careful. Six to eight feet from buildings is a good rule of thumb. Just remember that your new Japanese maple WILL grow, so plant it far enough away from things that could hurt it. The same goes in garden areas . Even dwarf trees can get pretty big . Dwarf trees come in many sizes, just like “little people.” They will never be as big as a non-dwarf upright or many dissectums, but they can get taller and wider over time. The good news is that dwarfs are usually bushy, twiggy, and short-branched, which makes them VERY easy to keep trimmed even for a beginner. So, your worry is probably not justified, unless you don’t want to or don’t have time to trim.

If you have to keep your Japanese maple near a building or other thing, you could just keep it in a pot all the time. That will allow for easy movement and even keep the tree smaller than if it were planted out. Japanese maples can live happily in pots for a very long time if they are properly “upsized” (re-potted in bigger pots) and their roots are pruned every so often. If you don’t have much room but really want to plant it near a building, choose a dwarf tree or small dissectum (but keep in mind the problems with the back of your tree mentioned above). As was already said, you should know that “dwarf” and “small” are relative terms that can mean different things depending on the size. The tree is usually less than 5 or 6 feet tall, but it may “like” where you put it and grow 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. When planted outside, most Japanese maples do best in zones 5b and warmer. Some can do well in zones 5a, but not many. However, the zones are shifting. My area has been moved from 5b to 6a on the new zone chart, which is based on temperatures over the last 20 years (Global Warming). (A new zone chart with “micro climate areas” is being made, but its accuracy will always be questionable, just like all zone charts.) Zone assignments should be taken with a grain of salt. Some cultivars might work well for you, but a good friend of yours 5 miles away won’t. This is true even though he/she is using the same exact cultivation techniques and placement as you are. And the yard of your neighbor or even just a part of your yard might be warmer and better for Japanese maples. Such places are known as microclimates, or “mini-microclimates” when they’re in your yard or neighborhood. There may be microclimates where one person is more successful than another in colder areas or colder areas within warmer areas. These can be caused by things like a fence blocking the wind, being higher up, like on a hill, being close to large bodies of water, or snow acting as insulation. The -20 area in my sap app and the drop-down menu next to “available trees” (at the top of this page) that says “other hardy Asian maples” will show which Jms are the hardiest. Those 5a “colder” people should give those trees top priority. Most other cultivars I have listed on the site will also likely do just fine too. There is no need to spend money on something that you can’t be sure of. Choose plants that are listed as very hardy or keep them in a container, which is not a big deal as you will see below. I always advise those in far northern areas to do container growing . it is easy and will allow for the growing of ANY Jm.

Also, keep in mind that, just like in 2007, if we have another long stretch of warm weather in March that lets Japanese maples fully leaf out, followed by a long stretch of teen and twenty-degree weather in April, many Japanese maples will not be able to survive. The strange event that happened hurt and killed a lot of these trees from Texas to the east coast and as far south as Atlanta. This was good for Japanese maple sellers because they had to replace a lot of dead trees. This unusual occurrence actually did more damage the farther south you went in zones 6 and 7+. Many trees made it through and grew new leaves, but many others had their bark severely damaged by flowing sap that froze and peeled off, killing them in the end. I had some losses here, but 90 miles south, in St. Louis, it was devastating. In a strange twist, Japanese maples did not die in Chicago or other zone 5a areas in southern Wisconsin that are usually not good for growing them because they get more late frosts and freezes. Instead, they had a great growing year. This was considered a once in (a lifetime) 50 -100 year happening. But who knows? As the saying goes, “the only thing certain in life is death and taxes.” So this information on hardiness should also start with “depending on normal weather for your area or at least not having historically bad weather this year.” Also remember some Jm’s bud earlier than others . This won’t help in a real emergency like the one we had in 2007, but it can make a HUGE difference in the spring. Stay away from a cultivar that says it blooms “early” if you live in a place that gets late frosts often, especially if there are warm periods followed by occasional frost periods. If you pick a cultivar , read my description where these early budding trees will be noted . I use to just not sell them. But since I have a lot of customers from the south and some are growing JMs in containers, I chose to do it with the ones I think are really cool. But I list and carry them list with a statement concerning early budder’s in each description.

I will make this straight-forward statement here, that you will also see on many Japanese maple related sites. Japanese maples do best in places that get morning sun and afternoon shade or all day light sun with clouds. No matter where you live, even plants that do well in full sun or a lot of shade will do better in this spot. The only exceptions are a few very 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. Like me, you may quickly run out of these great spots depending on the size and shape of your yard and how many Japanese maples you end up getting. It’s likely that you’ll quickly buy a lot of Japanese maples once you get hooked on this beautiful tree. (And you will get addicted!). If these great spots are taken, you’ll have to choose cultivars that do well in either sun or shade, depending on your situation. Depending on how hot it is and how old the tree is, even the sunniest cultivars will be partially or fully burned by mid-summer. An older tree will help protect against this. If you have all deep shade you will get less and perhaps atypical growth and color . When it comes to Jm’s, too much sun can burn the leaves, and too little shade can cause the plant to grow slowly and in strange ways, with limited or different coloration. Most Japanese maples, on the other hand, will do well in either moderate shade or moderate sun. Too much of either can be bad for them. If you don’t have a sweet spot or enough of them, pick your poison: a few months of great beauty followed by a month or so of a plant that doesn’t look great but has great fall color; or mid-season beauty with some good fall color. If you have a choice between full sun or full shade I personally would take the shade.

All Japanese maples need a period of cold winter dormancy. That’s one reason they shouldn’t be kept inside!! It’s also why many of them won’t grow well (or at all!) in places that are warm all year and don’t get cold enough to dormancy…. Trees in these areas will grow but tend to decline over time . But even though they need the colder dormancy period, most cultivars will do better with some extra protection in the winter. Blockage from winds helps give the plant some protection and helps with containing winter die back. If you protect the bark from the direct south sun, the bark won’t split as much during the day and at night when it’s very cold. During the day, the sap will start to flow. It will then freeze inside the tree, which is what happened during the big spring freeze we talked about above. I think bark split from many JMS is worse than wind and cold, but it’s usually not fatal and can heal over time. However, your tree may have a side that doesn’t grow branches, making it lopsided. It seems to help to cover the trunk with semi-hard, slitted tree wrap that can be cut to size and has holes for air flow in the winter. Just remember to take it off in the spring.

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. It’s simple: “mulch early and often.” But stay a little away from the trunk to avoid damage from bugs or water. (SEE MULCHING SECTION BELOW. ).

Your Japanese maple will be safe from winter damage if you put it in a container and put it somewhere warm and dry. If you don’t want to heat your garage or outbuilding, you can bring a potted tree inside until spring. Make sure the tree is away from windows and out of direct or indirect sunlight. You might have to do “the old in-and-out-shuffle” in the spring if it gets warm during the day but stays cold at night. This is because your trees might break buds in the garage before you want them to. I’d rather do this than burying pots or “Christmas wrapping” trees and pots in insulation sheets, etc., which I think is silly and takes 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. But in areas as far north as mine I really don’t suggest it. I used to leave bigger pots (five-gallon or bigger) outside all winter in a safe spot or on the porch, but I don’t bury them. My experience with this has been mixed, but mostly negative ie: disastrous. If you live somewhere where it’s below 18 degrees and there’s no snow, I don’t think you’ll be happy with what happens if you leave pots out in the open. Even bigger pots should be kept inside. You should do so at your own risk. If it rains a lot and your pot freezes with waterlogged roots, the damage is more likely to happen. In that case, you will probably 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. A bigger pot protects the soil better, but as I already said, this is only true in warmer winter places. Even larger pots will be of little help in -15 degree temps the roots will likely die totally . Better be safe than hysterical . Also, it’s not a big deal to bring pots inside a building; you might even have to do the “shuffle” if you only have a few big ones. and I now recommend this. Bringing pots into your garage or out-building also saves having to devise critter protection. As I already said, growing Japanese maples should be fun, not hard, so don’t make things harder than they need to be or keep an eye on them all the time. You also don’t want a disaster.

It is very important to protect your tree from critters even if you think they are not around. Animals can do a lot of damage to your Japanese maple trees from the winter until late spring, when they can find better food sources. Rabbits, deer, mice and other rodents can be a curse. If you only have a few small trees, a 24′′ to 36′′ tall roll of chicken wire tied to 3′ lengths of 1/4′′ rebar will work fine. You can get both of these things at most hardware stores. You only need a cheap pair of tin snips and a hammer to hit the rebar with if the ground is hard.

Three or four rebar should be pushed or hammered into the ground about a foot or two away from the tree in a square or triangle 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. For bigger trees, plastic tree guards can be put on in the fall and taken off in the spring. Make sure to take them off in the spring, or the tree could become a place where bugs and fungus grow. A bigger tree isn’t likely to be attacked, so you probably don’t need to protect it there, unless you REALLY have a problem with too many deer. Then you just have to build a giant wall around your yard….

Watering your container grown Japanese maples

FAQ

Can Japanese maples be overwatered?

Can Japanese maples survive in pots?

How do I know if my Japanese maple needs water?