How to Care for your Japanese Maple over Winter

People are always curious what to do with their plants in the cold. Luckily, Japanese maples are some of the most cold hardy trees there are. However, there are still several things you need to know when caring for your Japanese maple over the winter. Whether it’s how to handle the watering or whether to protect it from extreme temperatures or a myriad of other things that can happen in the cold, this article is going to fill you in on all you need to know on how to care for your Japanese maple over the winter.

Let’s start by talking about what winter is rather than what it is not. Winter is actually an opportunity for the Japanese maple lover. Winter, and a Japanese maple’s dormancy period, is the perfect time to do all sorts of things with your tree. If you have an older specimen, it’s the best time to prune your tree. If you have a tree you want to move, then it’s the best time to dig it up and transplant it. Even if your trees are in pots, winter is the best time to transplant them into bigger pots. Winter is full of opportunity when it comes to your Japanese maple.

Winter Pruning of your Japanese Maple 

If you’ve been thinking about pruning your Japanese maple, then now is the time to do it. Minor pruning can be done at any point in the year, but you want to perform any major pruning in the winter while the tree is dormant. The tree is much less active this time of year and won’t be put in as much shock by pruning off large limbs. You still want to remember never to prune more than one third of the tree off at any one time. If you have a major amount of pruning to do on a Japanese maple, you can always do part of the job this winter and then finish up next winter. When pruning off small branches in the spring or summer months, we like to use what we’ve coined the pinky rule. If the branch is skinnier than your pinky, then you can clip it at any time. I’m no pruning expert and I don’t try to be, but these are some basic pruning rules that I’ve picked up in years of growing Japanese maples. 

Planting your Japanese maple in the Winter

There’s an old adage that my father used to say, “The best time to plant a Japanese maple was 20 years ago, the second best time is today.” This is 100% true. People are always asking when they should plant their tree, or they’ll say they want to wait until the spring or wait until the fall. What are you waiting for?? The sooner you get your Japanese maple in the ground, the sooner the roots get established and the sooner your tree can start growing. So, don’t worry about the time of year, just get that tree in the ground. 

Now that I’ve laid out the blanket rule that you should always want to get your Japanese maple in the ground as soon as possible, let’s dive into a few winter specific things to know when planting your maple in the cold. A huge benefit of planting a Japanese maple in the winter is that it drinks very little water this time of year. As long as we get some rain about every two weeks, the tree should be fine. This is a far cry from the treatment that a Japanese maple needs when planted in the summer. Not only does your tree not need much water in the winter when you first plant it, you also won’t have to water it much all year. When planting a Japanese maple in the winter, you’re giving your tree time to get establish and acclimated in your yard. By the time spring and summer role around your tree should be established to the point that the rainwater is keeping it satisfied. Still make sure it’s receiving water about every two weeks, but that usually is something the rain can handle. 

While I believe that these benefits far outweigh the downfalls, there is one major concern with planting a Japanese maple in the winter, especially here in the south where we get crazy winter weather fluctuations. As long as a Japanese maple is dormant, it can handle temperatures even as low as zero degrees. However, we often have stretches of warm temperatures in February that cause some of our trees to leaf out in late February or early March. While we’re as excited for an early spring as anyone, there is always at least one freeze or frost that occurs in March or even early April. Japanese maples do not handle freezing temperatures very well when they are leafed out. We suggest protecting any Japanese maple from freezing temperatures after it has leafed out. This can mean bringing smaller, potted trees inside your garage overnight, or covering up your larger, in-ground trees with some sort of sheet that is not too heavy as to break branches. Obviously, protecting your trees once they are in the ground is much more difficult than while in a pot, making this really the only major downfall of planting during the winter. 

Transplanting your Japanese Maple in the Winter

You can transplant your Japanese maple from one pot to another any time of the year. However, winter is the only time that I would recommend ever digging a mature tree out of the ground. This concept is similar to that of pruning. Your Japanese maple is least active in the winter; therefore, this is the time of year where you will disturb your tree the least by digging it up. Even still, you want to be very careful when taking a Japanese maple out of the ground. Make sure to dig a wide enough hole as to disturb the roots as little as possible. The root ball will typically extend to the drip line or the canopy of the tree. Once you have removed the tree from the hole, make sure to immediately place the tree into its new hole or container and water thoroughly. As long as you follow these steps, are very careful as to disturb the tree as little as possible, and transplant during the winter, then your Japanese maple should be completely fine. 

Keep your Japanese Maple Healthy over the Winter

More than all of this other information, you probably started reading this article because you want to know the best way to keep your Japanese maple healthy over the winter. Luckily, there isn’t a whole lot that you need to do to keep your tree happy and healthy. Japanese maples are tough trees that are usually killed by kindness more than anything else. My first tip is not to overwater your tree in the winter. As I’ve mentioned before, Japanese maples are not actively growing during their dormancy period and hence aren’t drinking much water. This fact coupled with slower water evaporation in the winter causes moisture to stick around in the soil much longer. This will give your maple wet feet, which is one of the worst things you can do for your Japanese maple. Roots that stay wet can rot or develop diseases such as Pseudomonas syringae, Pythium, or Verticillum wilt. This is why proper drainage is so important for your Japanese maple year-round but especially in the winter. 

Another thing to keep in mind when caring for your Japanese maple over the winter is fertilizer. You want to refrain from any fertilizing in the winter. Wait until spring before fertilizing your Japanese maples. Japanese maples need the winter and their dormancy period, and that shouldn’t be rushed. We usually wait until early to mid-April before fertilizing as we want to be sure that the trees are done with their dormancy. Patience is absolutely a virtue when it comes to Japanese maples. Be patient with your dormant maples and they will likely reward you in the spring.

Shopping for a Japanese Maple while Trees are Dormant

It is often said that the winter isn’t a great time to shop for a Japanese maple because they don’t have any leaves on them. However, I want to buck back against that notion. It’s true that it can be difficult to determine how much you will like a certain tree without seeing its leaves, but more often than not leaves can be a distraction when picking out a tree. So often people will pick the tree with the prettiest leaves on it regardless of the circumstances. While the leaves are great, you don’t want to ignore the trunk and branching structure of the tree. When shopping in the winter, you can see the structure of the tree without the allure of the leaves impeding your view. Of course, the leaves can help you decide which variety of Japanese maple you would prefer, but if you’ve done your homework and know what you want, then choosing the perfect maple without leaves may actually be a better strategy. 

Winter is obviously a time of great consternation among gardeners. All of these cold days can make it hard to wait for spring but remember how important winter actually is for Japanese maples and the garden. This season is full of opportunity for us to alter and manicure our gardens. Spring is right around the corner and I hope this article helped get you through the cold.