Growing Osage orange (Maclura pomifera) takes planning and consideration because their sharp spines, dropped fruit and irregular growth habit make them difficult to place in most gardens. The osage orange trees grow best within U.S. Department of Agriculture plant hardiness zones 4a to 9a, where they will thrive despite poor growing conditions and neglect.
How to Grow Osage Orange from Seed
# 1 | Mositen a paper towel (not soaking wet) and place your osage orange seeds in the center. Fold the paper towel around your osage orange seeds. Place paper towel and seeds in a plastic bag and then inside the refrigerator. Leave undisturbed for 15-20 days.
# 3 | Set the pots in a bright, warm location and keep the soil moist but not sopping wet. Temperatures above 68 degrees Fahrenheit are best for germinating Osage orange seeds, so set the pots on a propagation heat mat if the environment is too cold.
# 4 | Watch for seedlings in 30 days but don't be surprised if it takes a little longer. If both seeds germinate, choose the strongest and most vigorous seedling and snip off the other one at soil level using small, sharp scissors. Remove the propagation mat after germination if one was used and keep the Osage orange seedlings under very bright and sheltered conditions until they produce mature leaves.
#5 | Osage orange trees will tolerate a wide range of growing conditions, including very poor areas of the garden where few other shrubs would thrive. This species produces very sharp spines that can cause injury and dropped fruit that stinks when it begins to decay, so choose an out-of-the-way growing location where these traits won't be an issue.
#6 | Transplant Osage orange seedlings in autumn in climates with a mild winter and in spring in colder areas.