Plantados, the most stubborn political prisoners in Fidel Castro's jails, the ones who endured the harshest punishment. In 1961, the Cuban penal system introduced a progressive rehabilitation program. Those who participated willingly attended political education classes and performed manual labor. They were generally treated better, allowed more visits and released sooner. Those who stood on principle and refused were called Plantados - the immovable ones. The plantados rebelled against forced-labor, working as slow as possible. Some died from the beatings they were given. Later, when regular prisoners were given blue prison uniforms, the plantados were left with only their underwear. For many years Castro refused to free plantados who had once been his allies. 
In the 1980s, a new group of prisoners say they have become the new plantados.
The first three "Plantados" were: Alfredo Izaguirre de la Riva (the first), followed by Emilio Rivero Caro and Nerín Sánchez Infante. Time later they were followed by: Odilio Alonso, Juan Roque Maya, Gregorio Ariosa Rubio, Carlos Moreno Pacheco, José Varona Primelles, Ricardo Vázquez Pérez, Israel Abreu Villareal, Gabriel Abay Jach, Pedro Luis Boitel Abraham (died on hunger strike), Eriberto (died on a hunger strike), Ricardo Rangel Mendoza, Julio Reyes Suárez (he was driven mad In the pavilion of punishment), Antonio Vigo Cancio, Antonio Rodríguez Galano, Juan Pérez Báez, and Roberto Pavón Pena. Then they were followed by thousands more.
Mario Chanes de Armas, in 1991, after 30 years, he was the last Plantado to be released. He was originally among Castro's closest allies, participating in the attack on the Moncada barracks thus helping bring Castro to power. He turned against Castro early in the revolution.
Armando Valladares, author of the book, Against All Hope: A Memoir of Life in Castro's Gulag, his autobiographical story as a plantado.
Nerín Sánchez Infante. Captain (Castro Revolutionary Forces), Anti Castro Guerrilla Leader, Political Prisoner, Imprisoned for 19 years by the Castro regime, (Charge-Causa 947-1961), 1 of 3 original “Plantados”, Founder and Commanding General of the “Ejército Rebelde Juramentado”, Anti-Castro Rebel Army later organized during imprisonment, (Charge-causa: 66-1975), Sentenced to 12 additional years) also known as “O.R.A.C”.(Organización Revolucionaria Anti Comunista). Wrote a book: "Los Plantados".
- http://www.fiu.edu/~fcf/plantados.html Lourdes Fernandez and Alfonso Chardy, Miami Herald, 1996