Why do thuja turn yellow and brown?
Pine, a genus of coniferous trees of the pine family. These are evergreen trees that can live 400-600 years. But what to do if your pine is not so green, and in some places you can see yellow needles?
Do not panic at once, thinking that the tree is disappearing or has already disappeared. Yellowing needles do not always indicate a problem.
Seasonal dumping of needles.
As deciduous plants drop leaves in autumn, so evergreen plants periodically drop their needles. Unlike deciduous trees, which drop all their leaves at once, pines, dropping old needles, retain most of the needles. Old needles turn yellow before falling off and the trees may seem sick.
Pine trees tend to shed needles in the fall, although they can shed them at other times of the year. The lifespan of needles is about 3-5 years, after which they are replaced. Most pine species retain their needles for several years before the old three-year-old needles fall.
Old yellow needles that drop pines, located closer to the inside of the tree. Because the young needle, which remains green, is on the outside of the tree, seasonal shedding of needles may go unnoticed in most species. However, white pine is an example of one species of pine that can lose a significant amount of needles in the fall.
Environmental factors that cause the fall of needles.
Pines are sensitive to wind damage. After a strong storm, the needles may turn yellow, and some trees eventually die. Some pines may remain green for a year before the needles turn yellow on the entire tree.
Pines can react to sharp fluctuations in temperature, especially in autumn, plant tissues can be injured, which eventually causes yellowing of the needles.
Road salt that gets on pines can burn plant tissues, causing yellowing of needles. Even air pollution can lead to pine disease.
Pine gets sick and turns yellow when transplanted.
The shock of transplanting can cause the needles to turn yellow, even if the tree is planted correctly. Improper planting techniques, such as planting a tree too deep or not enough water until the plant has taken root, can turn evergreen pines into yellow pines.
Planting pine trees in hot weather instead of autumn or winter can cause the needles to turn yellow first, and then completely turn brown.
All plants need water and nutrients, but individual needs depend on plant species. A number of nutrient deficiencies can cause the leaves to turn yellow.
One example is nitrogen deficiency, which can cause needles to turn yellow. Pines and other plants should be fertilized according to the recommendations of soil tests to make sure that you meet their needs.
Pests and diseases, yellowing of needles
If your evergreen plant turns yellow in the spring, the culprit may be several pests that feed on pine needles: mites. As their feeding progresses, symptoms include curvature and yellowing of the needles.
If the needles turn brown, you need to check the tree for the presence of bark beetles or bast eaters. Another pest of pine is the foliar nematode. Nematodes feed on plant tissue, which makes the needles yellow.
The cause of yellowing can be the following diseases: fusarium wilt, shingles, rust.
In any case, if you find yellowed needles should consult a specialist. Timely and correct treatment gives an effective result, and pines will delight with their greenery and aroma for many years to come.