The 'Ponderosa' lemon tree is not actually a real lemon tree. It may be a crossbreed of a lemon tree and a citron tree, and was found by chance in the 1880s. Despite being related to lemons, 'Ponderosa' is more susceptible to frost and cold temperatures. The 'Ponderosa' lemon tree is only able to survive in plant hardiness zones 9 through 11, and is more frost-sensitive than other lemon trees. Despite being seen as an ornamental curiosity by some, it requires the same care as other lemon trees. The tree produces large, highly acidic lemons throughout the year. To properly water the 'Ponderosa' lemon tree, make sure to water it thoroughly to ensure the soil is evenly moist, but not too much to avoid making it too soggy or wet. During the growing season, let the top layer of soil dry out slightly before watering again. For container citrus, more frequent watering (once or twice daily) may be necessary during hot months. In the fall and winter, water only when the top in. of soil feels dry. Ponderosa lemons are typically grown in containers and used for decoration on patios or as a front door plant in California and Florida. It can also grow well indoors, but it should be kept away from direct sunlight and drafts. In colder areas, additional lighting may be necessary. When planting a Ponderosa lemon tree, select a container that is 1 size larger than its current container. Citrus trees prefer soil that drains well and allows for good root aeration, such as a clay mixture.