Evergreens are types of plants that have leaves throughout the year, hence their name. They keep their full foliage throughout the winter. There are many varieties of evergreens, including both shrubs and trees. The majority of conifers, angiosperms, gymnosperms (such as cycads), live oak and holly trees are evergreen.
When cultivating evergreens, it is important that the plants have full sun. In some cases, evergreens can manage partial shade. The majority of evergreens do well with supplemental watering during warm, dry and windy times (between November and March). Evergreens thrive with mulching. Most evergreens have varying water preferences. Some of them are tolerant of drought.
There are many varieties of evergreens. Some of the most well-known types of evergreens include the Oriental spruce, Norway spruce, pitch silver fir, Colorado blue spruce, Swiss stone, white pine, elegant yew, American arbor vitae, Austrian pine, weeping Norway spruce, common European yew and heavy-wooded pine.
As with the majority of plants, diseases can affect and damage evergreens. The most common diseases result from fungi, which extracts nourishment from trees by acting as a parasite. Viruses and bacteria can also bring upon diseases for evergreens. Some common evergreen diseases are canker tree disease, needle cast tree disease, needle blight tree disease and root disease.
Pests also can be bothersome and destructive. Some common insects that plague evergreens include mites, pine needle scale, Zimmerman pine moth and pine tip moth. Pest infestation has symptoms such as white foliage, needles turning brown and dropping, branches snapping off and resin collecting around the tips of buds.
The term "evergreen" identifies trees that generally keep their entire foliage throughout the winter. However, they do not indefinitely keep all of their foliage. One example is the Ponderosa pine, which drops needles that are between three and five years old on an annual basis. The oldest needles of the tree stay near the trunk, while the younger ones are closer to the branches.