Why Is My Evergreen Turning Brown And Losing Needles?

Was there any adverse weather like extreme winter cold or extreme summer heat recently?

Was there a prolonged period of drought?

Was your evergreen flooded for a prolonged period?

Does your evergreen grows near the road?

Does your evergreen grow in a confined space or was there a construction works and heavy equipment recently?

Delayed winter injury, heat stress may cause damage to the cambium layer just beneath the bark. This damage interferes with the uptake of water and nutrients which can lead to needle shedding.

Lack of water damages or kills back some of the roots, in particular, the tiny and sensitive root hairs. When the roots are damaged, the trees are not able to pick up enough oxygen which is needed for photosynthesis. This causes the trees to be stressed and the needles to die out much faster than normal.

Prolonged exposure to standing water causes damage to the root hairs of the trees – these are specialized, very fine roots that are responsible for water, nutrient, and oxygen uptake in the trees. When the roots are damaged, the trees are not able to pick up enough oxygen which is needed for photosynthesis. This causes the trees to be stressed and the needles to die out much faster than normal.

Soils just beside the roads can have a high concentration of salts due to the anti-frosting salts used during winter. Water in the soil that has a high concentration of soluble salts causes salinity. The salts in the water are toxic to trees, shrubs, and other plants.

If your tree is growing in a confined space it may have overgrown its allowed space, and if there was heavy machinery near the tree, the soil might have gotten compacted. Fifty percent of soil is generally minerals and other materials, 25% is water and 25% is air space. Compacted soil has very low air spaces. Roots need these spaces for the uptake of water, oxygen, and nutrients. Compacted soil also tends to stay wet which causes root rot.

Coniferous trees don’t keep their needles forever. The loss of needles on conifers in the fall is normal and natural. This is when coniferous trees shed their oldest needles, the ones located closest to the trunk. This is called seasonal needle loss. The needles turn yellow or brown first, before dropping to the ground. Every year a conifer will grow a new set of needles and every year it will lose an old set of needles.