Elemental Control: The Swamp Thing has complete mastery over all forms of plant life and can command vegetative matter to do his bidding. Through this power, he is in constant communication with the very essence of the Earth, and serves as the Plant Elemental for the entire planet.
In the past Alec Holland has gained access to other elemental powers. At one point gaining control over earth, water, air, and fire in addition to that of plantlife. However, often almost immediatly gaining control over all of them, giving up all but his connection to the Green.
Superhuman Strength: The Swamp Thing's strength level is directly tied to his connection to the Earth. Occupying his most commonly used body, the Swamp Thing is capable of lifting volumes of mass many times greater than his own body weight. With additional power supplied to him by The Green, his ultimate strength level is nearly incalculable.
Immortality: Theoretically so long as there is some vestige of plant life on the planet Earth, Alec Holland will always have a vehicle through which to house his consciousness, thus rendering him effectively immortal.
Resurrection: The Swamp Thing houses his conscious mind inside of a faux body made up of compacted flora and vegetative material. At will, he can abandon this host form and take up residence inside of another shell. Even if the body he is currently occupying is destroyed, Alec's mind lives on and will reconstitute itself in a newly grown swamp-form. The Swamp Thing operated for several years before he even became aware of this ability. Eventually, it was the occultist John Constantine who revealed Alec's Elemental nature to him, and instructed in the ways of reconstituting a new body.
Chlorokinesis:The ability to commune with plantlife and to varying degrees control its growth and form. Summon forth vines to entangle or snare, and so on. A master of this ability can manipulate the microscopic algae inside of a person's body and use it to attack them from the inside out.
Self-Sustenance:The ability to nourish oneself, typically via an external energy source. In Swamp Thing's case, likely through a form of photosynthesis.
Chemist: Brilliant Chemist
Biologist: Brilliant Biologist
As the Swamp Thing, Alec Holland possesses superhuman strength (See Powers); As a human being, Alec Holland possessed the strength level of a man his age, size and weight who engaged in moderate regular exercise
Pollution: pollution is highly dangerous to the plant life that makes up his body and the plant life he is connected to.