My Pine Trees Are Turning Brown …. Why?
The pine tree next to my office window that greeted Spring with an abundance of green needles, now shows a lot of brown needles and the promising Spring appearance is fading away quickly. We do see a browning of pine needles in plantations and along roadsides with the arrival of Spring. Of course, it depends on the species of pine to determine whether the browning is normal or can I do anything to help the tree to overcome a disease?
So let’s look at the different pine trees. It all starts with looking at the needles that cluster together in groups. They are called fascicles. Besides the bark, size and general shape of a pine tree, you can identify the type by looking at the fascicles. Count the needles in a fascicle and you know what kind of pine tree you are dealing with. For example:
So let’s look at the different pine trees. It all starts with looking at the needles that cluster together in groups. They are called fascicles. Besides the bark, size and general shape of a pine tree, you can identify the type by looking at the fascicles. Count the needles in a fascicle and you know what kind of pine tree you are dealing with. For example:
White pines have five needles in each fascicle. The needles are soft and often pale green. The cones of white pines are slender and 4 inches or even longer.
Austrian and Scots pines belong to a group of hard pines, together with the American jack pine and red pine. Hard pines have only two or three needles in each fascicle.
Reflected burn from wall If pine trees are along a road that sees a lot of salting during the Winter to keep it drivable, pines- especially white pine, will probably survive one winter and not more. There is also the so-called ‘winter burn’, usually on the ‘sunny’ side of the tree. If the lower branches were buried under the snow during Winter, they would survive the burn.
There is also the needle blight. Usually you have this disease in Austrian pine. A fungus called Mycosphaerella pini will affect trees of all ages and eventually kill them. It is easy to spot because the needles are brown at the tip, whereas the rest of the needle is still green.
There is also the needle blight. Usually you have this disease in Austrian pine. A fungus called Mycosphaerella pini will affect trees of all ages and eventually kill them. It is easy to spot because the needles are brown at the tip, whereas the rest of the needle is still green.
Mycosphaerella pini
Needle Cast When you deal with the needle cast diseases-which affects Scots pine as well, you may see an entire tree brown in the Spring. The needles are infected from spores being released by black fruiting bodies that form on the fallen needles.
Needle cast diseases are caused by various fungi that infect the new needles on pines, spruce, Douglas fir, and true fir. Although the needles become infected, symptoms may not be visible until the following Winter or Spring seasons. So it may be a good idea to check fallen needles on the ground for dark fruiting bodies as an early warning sign, particularly if you see symptoms on neighboring trees that may signal an incipient infection. The symptoms may appear also on interior needles, which may turn brown or yellow, and shed prematurely, and also show the dark fungal fruiting bodies. If your tree looks more sparse this year than last, you may want to look for these symptoms so you can treat the tree. Often the only needles remaining are the current season's new growth, so spotting this should be easy. Treatments can be applied with a fungicide from late July through August.
Needle cast diseases are caused by various fungi that infect the new needles on pines, spruce, Douglas fir, and true fir. Although the needles become infected, symptoms may not be visible until the following Winter or Spring seasons. So it may be a good idea to check fallen needles on the ground for dark fruiting bodies as an early warning sign, particularly if you see symptoms on neighboring trees that may signal an incipient infection. The symptoms may appear also on interior needles, which may turn brown or yellow, and shed prematurely, and also show the dark fungal fruiting bodies. If your tree looks more sparse this year than last, you may want to look for these symptoms so you can treat the tree. Often the only needles remaining are the current season's new growth, so spotting this should be easy. Treatments can be applied with a fungicide from late July through August.
And of course you have old age
Trees may live to a maturity, then to old age, and the dying process is slow and may take centuries to complete. A tree does damage control around an infected or damaged area and still continues to grow. Growth will slow down a bit when it matures, but it still is able to support adequate foliage for hydration and food. There might be some immature new branches called epicormic sprouts, which try to assist the tree. Usually though they are too weak and insufficient to support life for long. Slowly the tree collapses under its weight. Its decaying body becomes host to myriads of creatures and fungi that will break it down as part of their own life cycles, feeding them and spawning their new generations. Eventually, it becomes the nutrients and topsoil for future trees.
Trees may live to a maturity, then to old age, and the dying process is slow and may take centuries to complete. A tree does damage control around an infected or damaged area and still continues to grow. Growth will slow down a bit when it matures, but it still is able to support adequate foliage for hydration and food. There might be some immature new branches called epicormic sprouts, which try to assist the tree. Usually though they are too weak and insufficient to support life for long. Slowly the tree collapses under its weight. Its decaying body becomes host to myriads of creatures and fungi that will break it down as part of their own life cycles, feeding them and spawning their new generations. Eventually, it becomes the nutrients and topsoil for future trees.
But now back to my original question: why is my pine tree turning brown? Browning needles in a pine can indicate problems. They are however a natural occurrence. Yes, pines are evergreens. That means there are green needles throughout the year. The trees however do not keep the needles forever and will dispose of needles which are three to four years old. This will happen in the Fall and in the Spring. These needles are shaded by the outer, newer, needles and do not receive enough light to photosynthesize and produce food for the tree. Pine trees shaded by other trees will also exhibit needle thinning.
Some years there appears to be more brown needles than other years. This is due to the fact that if needles from a good growing year are being dropped, there are many more needles. So, if the weather allowed for good growth four years ago, then this year we can expect a lot of brown needles.
Some years there appears to be more brown needles than other years. This is due to the fact that if needles from a good growing year are being dropped, there are many more needles. So, if the weather allowed for good growth four years ago, then this year we can expect a lot of brown needles.
A mature White Pine
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