The Joshua tree is the largest variety of yucca in the United States. They can crow up to 40 feet tall and have an average life span of 150 years. Some are thought to live as long as 300-500 years.
Joshua trees start growing as single stalks. The start branching when the growing tip flowers or is eaten by animals. Like many desert plants, the Joshua tree seeds must be dropped in a protected location, often in the protective care of a nurse plant that can provide shade and protect the moisture and nutrients for the younger plant to thrive.
Joshua trees are relative fast growers compared to most desert plants. They will grow approximately 3 inches per year during their first ten years and about 1.5 inches after that. They are found in the Mojave Desert between 1,300 and 5,900 feet.
Shown below are a few mid-day landscapes, Common Raven and Loggerhead Shrike.