The original mule palm was produced by hand pollinating the Queen palm (male) tree, Syagrus romanzoffiana pollen onto a Pindo palm , Butia capitata (female), and subtle variable trees have appeared in some of the seedlings, however, generally the seed grown trees conform to the original cross in terms of the cold hardiness and cellular characteristics of the above ground morphology. The reverse cross of this hybrid tree has been found generally to offer poor results in surviving for very long into commercially acceptable hybrids. Adult Mule palms can form pink flowers, but the seed are usually sterile, and those creations that have rarely sprouted are unacceptable in commerce. There have been rare instances when mule palms were being accidentally produced from palm collector gardens, where a Queen Palm tree was planted up close to a Pindo palm tree, and the viable seeds then fell to the ground and sprouted.
Mule palm trees flourish in well drained soil profiles and are adaptable in sandy soil or clay, and are generally tolerant for droughts for limited periods of time.
There have been online reports of Mule palm trees being grown in Alabama, Georgia and South Carolina, and of course, they have not faced the demands of being cold hardy where Mule palm trees have grown for years in California, Florida and Louisiana.