The word “cedar” may refer to a variety of trees, including both real cedars (of the genus Cedrus) and fake cedars. The Western red cedar, also known as Thuja plicata, is a coniferous tree that is indigenous to the Pacific Northwest. It thrives in USDA plant hardiness zones 6 through 8, making it a popular choice for landscape design. The Deodar Cedar, also known as Cedrus deodara, is a species of genuine cedar that may be found in USDA zones 7 through 9. What caused your cedar to become brown will determine whether or not the colour can be restored to its natural green state.
Normal Needle Loss
Cedars, like other evergreen trees, lose their leaves over time. This is a natural process. Instead, they lose just a few needles at a time in this manner. Even though they don’t lose all of their needles in the autumn as deciduous trees do, this is often the time of year when trees start to lose a greater amount of their needles. After becoming yellow, the needles eventually turn brown and fall off the tree. Do not be alarmed if you see some browning and loss of leaves all over the tree in relatively tiny quantities; the trees will still retain the majority of their green colour.
Cedar flagging is a more significant problem that is particularly prevalent on Western red cedar. [Note:] A tree is said to be flagging when its leaves starts to develop a brownish-red colour in huge regions throughout its whole surface. Even while it most often takes place during the long, hot, and dry summers when the tree has a depleted supply of water, it may take place during summers that are less severe if the tree has been subjected to adverse circumstances in the past, such as a very dry spring. In most cases, cedar flagging is nothing to be concerned about. The tree will often begin to regain its verdant appearance after a series of significant rainfalls.
Even though flagging is a natural reaction to periodic moisture stress that generally corrects itself, a cedar may be killed by a protracted drought that lasts for many years. For example, deodar cedars are typically able to withstand drought, but they will not do well if they are subjected to the stress of low soil moisture for multiple years in a row. If your region is going through a drought and you see that the needles on your cedar trees are turning brown, you should start giving them supplemental water throughout the summer. When a metal soil probe inserted at the tree’s canopy line can only reach a depth of three inches into the earth, it is time to water the trees. Water to the point where it can penetrate between 18 and 36 inches.
Cedar trees are susceptible to a wide variety of root rots. Root rot is caused by fungal organisms in the soil. These organisms enter the tree through its small feeder roots, then move into its larger roots, and eventually move up the stem and into the branches, where they cause needle die-off and, if the condition is not treated, eventually cause the tree to die. If you detect the rot in its early stages, amending the soil to increase drainage often works well, but fungicides have not been shown to have any impact. Dig up some roots and examine them if you have any reason to believe that they have root rot; the bark should peel off readily, and the roots should look black or rotting. Take care not to overwater your cedars, particularly when the weather is hot.