There are many reasons why evergreens become stressed. Needles change color and drop off naturally, but stressed plants can lose even more needles and discolor severely. Drought, herbicides, winter, frost, salt, animals, pruning and pollution can damage evergreens. Portions of the plant can turn red-brown, yellow, brown or reddish-purple in color. Leaves and needles then drop off, as the entire or part of the evergreen dies. Care for stressed evergreen plants in order to minimize damage and return the plant to good health.
Prune stressed evergreen plants to remove the evident damage. Remove dead, diseased and dying limbs and branches. Cut them with pruning shears where they meet healthy wood. Place the cut on the healthy branch, if possible, to avoid the spreading of disease.
Pinch off the tips of new growth to encourage the sprouting of more healthy foliage. You can snip off the tips, or candles, with pruners, but the ends will turn brown. Instead, pinch the stem off at the base of the needles.
Buy a fertilizer that supplies nitrogen, phosphorus and potassium in a ratio such as 10-8-6. The first number indicates a higher concentration of nitrogen, which promotes the growth of foliage.
Fertilize stressed evergreen plants in April, before new growth gets underway, for best results. However, you can actually feed plants up until midsummer. Use a drop spreader and apply the food underneath the evergreen branches and slightly beyond the border. Water well to promote the soaking in of the nutrients.
Transplant evergreens that are dying because they're not getting enough sun, they're in a windy zone or they're spaced too close together. Find a more suitable location in the full sun with well-draining soil. Transplant them in the fall.
Dig up as much of the roots as possible. Make a wide berth with the shovel to avoid root damage. Dig the new hole as wide and deep as the hole you've taken the stressed evergreen from.
Place the evergreen in the center of the new hole. Fill the hole with a mixture of the original soil and peat moss. Water until thoroughly moist.