The are marginal here. I live at the very northern most limit of where they can be tried here in Texas. They do much better about 125 miles to the south of me in the Rio Grande Valley, where the tall varieties can be expected to reach 40 to 45ft. in overall height with about 20 to 25ft. of woody trunk, and where the Malayan Dwarf varieties can be expected to reach about 25ft. tall in overall height with about 10 to 12ft. of woody trunk. The avatar picture I have is of producing Green Malayan Dwarf Coconut Palm along a large resaca (old river channel) in Brownsville.
With that said, here the talls could be expected to get to be about 20 to 25ft. tall in overall height here with about 7 to 12ft. of woody trunk, and the Malayan Dwarfs could be expected to get to be about 12 to 15ft. tall with about 1 to 3 ft. of woody trunk. The Malayan Dwarfs can start producing their first coconuts when they are only about 3.5 to 4 years old with a trunk as short as about 1.5ft. tall, whereas the talls don't start producing until they are about 7 years old and when their trunks are about 7 to 8ft. tall. The dwarfs stay somewhat smaller and are more resistant to a lethal disease in Coconut Palms called Lethal Yellowing, but the talls grow faster and produce a larger palm quicker and are a little more cold hardy. We get thousands of coconuts washing up on our Texas beaches in the spring, summer, and fall when the currents come up here from Tampico and Veracruz, Mexico, but in the winter, the currents head southward from the Louisiana Coast.
