Why The New Buds On Your Japanese Maple Tree Are Swelling (& The Easy Way To Fix It)

While it feels nice to get a streak of warm weather in the winter, unseasonable weather conditions can wreak havoc on some of your favorite plants. Most plants need a period of winter dormancy, a time of rest essential for healthy plants. Japanese maple (Acer palmatum), the gorgeous tree that boosts your home's value, needs a length of winter dormancy, which they typically enter just after dropping their leaves in the fall. Though these trees are very cold-tolerant, their ideal temperature range during dormancy is between 25 degrees Fahrenheit and 42 degrees Fahrenheit.

If the overall winter is mild or a warm streak occurs, their buds will swell — meaning that they are breaking dormancy, and the trees could start leafing out and suffer damage in subsequent freezing temperatures. It's unfortunately not possible to prevent your Japanese maple from breaking dormancy, but you can implement a technique to mitigate damage and get your tree back on track.

To prevent damage when the weather turns frigid after a warm spell, place potted Japanese maples that have begun to break dormancy in an unheated garage or shed. Use sheets or frost cloth to cover Japanese maple trees that are planted in the ground.

Avoid the mistakes everyone makes when caring for dormant plants, such as fertilizing, overwatering, and covering your Japanese maple with plastic. Your Japanese maple still needs to be kept moist in the winter, but don't overdo it. Don't fertilize during dormancy, as you will stress the tree by encouraging it to grow when it wants to rest. When you're covering planted trees that are breaking dormancy, don't use plastic, which locks in heat and will damage the entire tree as it forces out new foliage. 

One piece of good news is that if your Japanese maple does experience damage after breaking dormancy early, the injury is unlikely to affect the tree's health in the long run. Additionally, it's a good idea to review how to grow and care for Japanese maple trees before spring hits.