Native to the humid, temperate coastal ranges from Oregon to southern Alaska, the Alaska-cedar or Nootka falsecypress (Chamaecyparis nootkatensis) can tower 90 to 120 feet tall. When grown in garden settings, the tree usually peaks at a height no more than 45 feet. The cultivar Pendula is a more ornate form, with markedly more drooping scaly foliage, looking like an upright tree with weeping branches. Grow this weeping selection in U.S. Department of Agriculture plant hardiness zones 4 through 8.
Cultivar Pendula eventually matures to 20 to 35 feet tall with a spread of lowermost branches 12 to 20 feet wide. Not a good tree for regions with hot, arid summers or arid winters with drying winds, the weeping Alaska-cedar may mature to a smaller size in colder-winter regions, such as in USDA zones 4 and 5. In the wild, Alaska-cedar trees attain a dwarfed mature size at higher elevations in the Pacific Northwest.
Alaska-cedar trees have a moderate growth rate. Expect healthy plants to add around 8 to 12 inches of height or branch length annually. Growth is fastest and lushest in regions with high ambient humidity and warm summers -- not hot and dry summers. An acidic soil enriched with organic matter promotes the best growth and an evenly moist, well-drained soil is a requirement. It grows well in partial sun to partial shade, but will handle full sun if soil isn't too dry and the climate isn't too hot in summertime.
Weeping Alaska-cedar trees may experience unsightly and potentially lethal infestations of branch tip blight. It's particularly prevalent during seasonal wet weather in spring and summer and on young nursery trees grown in containers. Young trees, those less than 5 years old, can have entire branches die back, leading to plant death. Very old landscape specimens can also get tip blight, but the malady doesn't kill the tree. Juniper scales and bagworms may also affect plant vigor and need to be controlled before the pests cause harm and ruin the natural beauty of the weeping Alaska-cedar's branches and scaly needles.
Prune away dead or diseased branches on the weeping Alaska-cedar any time of year. Since this tree naturally attains a somewhat irregular but upright, pointed silhouette, pruning for appearance is not normally needed. Trimming off branch tips can limit the mature length of the branch, but it is not a healthy means to constrict the mature size of this billowy, graceful tree. Stumpy branches destroy the natural beauty of the weeping needles and horizontal branches.