Palmyra are massive palms. Do you have room for them ,you need more than one Borassus flabellifer they are dioecious.They seem to like damp soil for best growth.I have 10 and largest trunk is just shy of 4 feet thick in the dampest soil in the row.Also they have long juvenile time mine are 18 years old at least,and only one has flowered 2 times in row and it's male must be over 30 feet tall