What plant hardiness zone is Joshua Tree
Joshua Tree is located at San Bernardino County, California (CA), USA.
Plant hardiness zone (winter frost zone or gardening zone) for Joshua Tree is 9a by the USDA scale.
Coldest zone's winter temperature is +20 … +25 °F.
Plants of 9a USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 9a USDA.
Joshua Tree, California @ wikipedia.