Everyone knows that the leaves of deciduous plants live only a few months, bursting forth in spring and shedding in autumn. However, evergreens also shed leaves, usually in spring as the plant begins to grow. This spring, thanks once again to El Nino and a long period of cold, wet soils, evergreens are shedding an unusually large number of leaves. So many, in fact, that many gardeners think their evergreens are dying.

The leaves of evergreen plants may live from one to several years, depending upon the plant species. After producing new leaves, evergreens shed the oldest ones. Usually, the old leaves turn yellow, then brown before dropping.

Broad-leaved evergreens vary in how they shed their leaves. Many, like camphor, citrus, cork oak, xylosma and privet shed old leaves in spring as new ones are growing. Others, like carob, eucalyptus, sumac and magnolia may shed continuously from late spring through much of summer. The timing and duration of leaf shedding is often influenced by environmental stress. For instance, early, heavy shedding may occur after a severe winter, such as this year. It's important to realize that such leaf drop is normal, and not related to diseases or insect attack.

Conifers are different in that they normally shed their oldest foliage in autumn. Nearly all pines bear their needles in bundles of two to five, and the needles remain together when they drop. If the previous growing season or winter was especially stressful (hot, dry, cold etc.), some needles may be shed in spring, but most drop later. Arborivitae and related species bear scalelike leaves covering tiny branchlets, and these trees shed the oldest branchlets in autumn. As in broad-leaved evergreens, some leaf shedding is normal in all conifers.

You can keep leaf drop to a minimum by properly caring for your trees, especially when it comes to watering them. This year of course, there is nothing you can do about the excessively wet and cold soil. In most cases, trees will recover and grow well once our weather turns sunny and warm, and soil temperatures begin to rise.