Hinoki cypress can withstand a wide range of temperatures, but they occasionally get discolored from various issues. If you’re worried about your Hinoki cypress turning yellow or brown during autumn, you’re in the right place. These trees are quite adaptive, and they achieve this through shedding, changing colors, and more.
A Hinoki cypress will turn yellow in the fall if the leaves don’t have enough water or nutrients. Some Hinoki cypress trees get yellow needles near the middle during a process that makes room for new growth the following year. It’s common for these plants to change colors with the seasons.
In this article, we’ll dive into the reasons your Hinoki cypress might turn yellow in the fall, whether or not you need to take action, and what to look out for.
What Is Causing My Hinoki Cypress To Turn Yellow?
Many factors can cause a Hinoki cypress to turn yellow, including extremely cold weather, windy conditions, fungal diseases, and more. Root rot, a lack of adequate hydration, and overly nitrogen-rich soil can also cause yellowing needles on your Hinoki cypress. Keep an eye out for flooded soil, too.
Here’s a comprehensive list of reasons your Hinoki cypress is turning yellow:
- Frigid temperatures. The cold can damage the needles and prevent them from hydrating. While these trees can withstand cold weather, too much frost can prevent the plant’s cellular structure from distributing water properly. This will damage the needles and make them look light brown, dark brown, or yellow.
- Needle drop. This natural process can cause a Hinoki cypress to look yellow or light brown. It usually happens closest to the trunk of the tree or near the base of the branches and stems. However, a heavy needle drop season will also yellow the Hinoki cypress’s outer portions, too.
- Root rot and fungal growth. These are very common in the winter months. While root rot can’t be reserved, you can remove the damaged roots, stems, and needles to prevent them from spreading. Use an antifungal spray to treat your Hinoki cypress if you notice white mildew on the yellowing needles.
- Soil drainage issues. These aren’t rare when the dirt is cold, which could cause root absorption issues. Most soil gets compact and hard, making it difficult for water to absorb or drain out of the dirt. You can aerate the soil to loosen it up and add rocks near the base of the cypress to prevent it from flooding.
There are many reasons your Hinoki cypress could turn yellow. If it starts yellowing in the spring or summer, there’s likely a hydration, soil, or temperature issue. If the base of each branch is yellowing during the fall or early winter, it’s likely due to the needle drop process.
Read on for more information about how the changing seasons impact your Hinoki cypress’s temperature.
Why Is My Hinoki Cypress Turning Yellow in the Fall?
Your Hinoki cypress is turning yellow in the fall due to a process known as needle drop. Needle drop is entirely safe and natural.
The inner needles turn yellow and fall off, leaving enough space for new, vibrant needles to grow the following spring. Not only is it normal, but it’s quite a spectacle for cypress owners.
Yellowing needles are usually a good sign during the fall because they yield new growth. That being said, if the needles are brown or yellow at the tips, this could be due to various chemicals, bacteria, and fungi in the area.
Like many other trees, icing salts will often yellow the needles of a Hinoki cypress.
Yellowing is almost always natural in Hinoki cypress trees. If you’re worried that something else might be wrong, check the soil for mineral inconsistencies or root rot. Slime, mildew, and mushy soil are common symptoms of root rot and many other fungal infections around cypress trees and other plants.
If the green needles are healthy, flexible, and don’t break when compressed, there’s likely nothing wrong with them. However, fragile, crumbled needles often indicate an underlying issue.
How To Prevent a Hinoki Cypress From Yellowing in the Fall
Here you’ll find detailed step-by-step instructions on how to prevent your Hinoki cypress from turning yellow, provided this isn’t being caused by the healthy and normal needle drop.
- Test the soil conditions and adjust the dirt accordingly. Check the soil’s pH to ensure it’s as close to optimum as possible (slightly below 6.0)You should also ensure there’s enough zinc, magnesium, and other minerals that can be added through garden hose watering.
- Wrap the base of the tree with a burlap sheet to prevent winter damage. Try the Burloptuous Burlap Roll (link to Amazon). This fabric comes in a 40” x 14’ (1 x 4 meter) roll that you can wrap and cut to fit your Hinoki cypress. It’s breathable enough to let oxygen and moisture into the roots without letting them freeze.
If you notice the yellowing only occurs near the trunk of the tree, it’s more than likely caused by needle drop. Fortunately, there’s nothing you have to do about it. However, you should remove as many needles from the ground as possible since they can harbor bacteria, fungi, and pests.
While it’s not uncommon for a Hinoki cypress to change colors, it’s important to know whether or not you should be concerned. Some plant diseases can turn a cypress yellow, which shouldn’t be ignored. On the other hand, needle drop is a natural process that can make your Hinoki cypress look beautiful without causing any problems for the plant.