Growing evergreens in containers is one of the best ways to expand the size of small gardens and provide color throughout the year. The most appropriate evergreens for containers are ones that are small, such as the smaller species or the dwarf varieties of regular-sized trees. Evergreen trees planted in containers require more maintenance because their roots cannot grow beyond the walls of the containers to fulfill water and nutrient requirements; hence adequate amounts of both have to be provided in the pot. Nearly all evergreens do well in containers, and given the fact that the majority of them are slow growing, they can stay in an appropriate-sized container for many years.
Boxwoods (Buxus) are shrubs with glossy, dark green foliage. Their naturally conical or rounded shapes make for low-maintenance evergreens that require only minor pruning to keep in shape. Boxwoods are one of the best choices for planting in containers. There are basically two main species of boxwood, the Japanese boxwood and the European boxwood, and countless cultivars of both can be used in containers. Boxwoods are slow growing and grow in full sun or partial shade. They are not highly tolerant to extreme cold, and are susceptible to scale and root rot. Boxwoods can grow anywhere from 4 to 12 feet high depending on the variety.
Hicks yew (Taxus x media "Hicksii") is a shade-tolerant tree with an upright growth habit. Similar to the boxwood, it has Japanese and European varieties. Hicks yew is easy to grow as long as it is kept out of direct sunlight. Though the trees can grow up to 20 to 30 feet tall, they don’t grow quickly in containers. The Japanese yews are more tolerant of the cold than the European varieties. They are also more shrub-like and compact even though they eventually turn into small-sized trees. The needles on the Japanese yews are shorter, and the color is a deeper green. Yews grow best in full sun to shade and in a fertile, well-drained soil. The plants do not tolerate wet soil and are liable to get root rot.
Japanese cedar (Cryptomeria japonica) is also known as Japanese cryptomeria. The trees reach a mature height of 50 to 60 feet and have to be pruned to keep to desired size when growing in containers. Japanese cedar is a good choice for containers because it is low growing and easy to grow. The trees have a pyramidal shape and a moderate growth rate with a fine to medium texture. The trees grow best in full sun and light or heavy shade, and are able to thrive in a wide range of soils. The tree foliage is blue-green and smooth, and takes on a bronze shade in winter if exposed to high winds.