While Groot is a formidable brawler, he is not impervious (he is made of wood, after all), and often finds himself reduced to nothing but kindling.

Thankfully, planting even a splinter of Groot's remains allows him to regenerate and regrow.

  • How long does it take for Groot to regrow to "full" size?
  • Can multiple splinters of Groot be replanted? Would this result in multiple Groots?
  • 4
    For the second part of your question I'm guessing it's probably similar to the question of if you were to cut Wolverine in half would you get two Logans.
    – Monty129
    Commented Aug 4, 2014 at 16:45
  • 11
    "How does Groot's regeneration work?" It works very well, thank you. Commented Aug 18, 2014 at 8:09
  • 1
    I AM.... GROOT.
    – Omegacron
    Commented Dec 30, 2015 at 22:52

6 Answers 6


Groot - Marvel Cinematic Universe; Earth-199999

If Groot could speak intelligently he would tell you Groot is no mere wood! The citizens of Planet X, where Groot came from were an advanced starfaring species complete with scientists and a curiosity about life in the Universe. In Guardians of the Galaxy we are never told what happened to the citizens of Planet X, only that Groot is the last survivor of that species.

  • Groot's physical capacity for transformation, instantaneous growth and incredible durability ensure his survival under adverse conditions. He demonstrates an ability to spontaneously grow flowers, transform into vine-like barriers, and extend his limbs at will.

  • If Groot is destroyed, it is possible for him to return to full health and size though we are not privy to how long this would take in the MCU.

  • As to whether more than one Groot could be regrown, Rocket has never tried to grow more than one Groot at a time. We are not sure if it is possible or what the ramifications would be. It is unlikely any other unique "flora collossi" would come into existence from planting fragments of a shattered Groot, otherwise why would Groot's people be extinct? He would seed planets with himself if that were the case.

And like many of Marvel's regenerating life forms, Groot does not appear to need a corresponding amount of matter, i.e. water, minerals or soil to alter his size, shape or density, nor does he need such things while he is growing. Past the point of germination, Groot appears to be able to take everything he needs from the air, itself.

Groot - Canon Marvel Universe - Earth-616

Groot had only one appearance in the Marvel Universe, Tales to Astonish Vol 1, #13, Nov, 1960. He came to Earth to take a small town back to his planet for study. He was invulnerable to small arms and could take over trees and plants, turning them into a makeshift army. He was presumed destroyed when a scientist exposed him to altered termites which were claimed to consume him from the inside. (This was 1960, stranger stories were told.)

enter image description here

  • Groot does not make a reappearance in the Marvel Universe until we find him in a prison cell, held by the Kree, in the Conquest, Annihilation - Star Lord Vol. 1, #1 (2007). How he escaped Earth, survived his... infestation, etc, none of those things were revealed.

enter image description here

  • What we do learn is that Groot can recover from catastrophic injury in mere minutes! Albeit at a far reduced size... After being killed on his mission to free Hala from the Phalanx, Groot is believed destroyed, only to return to life at a diminiutive six inches. He is in all other ways, still Groot. He begins to grow again once given access to nothing but water (er... saliva) given to him by Rocket.

enter image description here

  • Later depictions in the Guardian of the Galaxy comics show Groot taking more time to grow after being replanted. In one part of the next volume, Groot was killed, repotted and grew quietly taking approximately a week to return to his normal size.

  • He is also more like his movie person, lacking any communication skills beyond his trademark I AM GROOT. However his technological capacity is not diminished. He correctly decants the imprisoned guardians from their fluid filled stasis prisons, which is not that curious because Groot has received the finest education from Photonic Knowledge of the Arbor Masters.

  • He is highly intelligent and has a tremendous grasp of quasi-dimensional super-positional engineering and according to marvel's wiki (Groot's abilities information) Maximus the Mad, Black Bolt's brother, asserted that whenever Groot is saying his trademark "I am Groot!" he has actually been saying any number of things. It is the hardened nature of Groot's larynx that causes people, who are oblivious to the subtle nuances of his speech, to misinterpret him as merely repeating his name.

enter image description here

Groot taking on the Spartax warriors who captured the other Guardians. He had been growing in a pot while the Guardians were captured and thus ignored.

  • 5
    "Rocket has never tried to grow more than one Groot at a time" -- in the MCU do we even know that Rocket has ever planted a Grootling before? If he knew this was possible, why the horrified reaction to Groot's actions at the end of the movie?
    – KutuluMike
    Commented Aug 15, 2014 at 21:40
  • In the MCU, he may have never tried to regrow Groot before. Commented Aug 15, 2014 at 22:31
  • @MichaelEdenfield, and even if he did, he probably still doesn't like it: maybe he knows it's not the same Groot, maybe he knows how long it'll take until he gets back to normal. Considering Rocket's reaction, I think either he hasn't tried it yet or the sproutling isn't the same Groot.
    – trysis
    Commented Aug 16, 2014 at 21:53
  • @MichaelEdenfield He has definitely regrown Groot on his own before. I just saw an image of him doing so yesterday. Sadly I don't remember where I saw it, so I can't link it for reference. But he was in prison, and had hidden a single splinter of Groot in his mouth (Groot refused to grow for two hours straight because he considered this form of transport a slight on his part).
    – Zibbobz
    Commented Aug 18, 2014 at 15:16
  • 1
    @MichaelEdenfield Ah, no it did not, but since this answer covers MCU and the comic book universe, I thought it was pertinent to share, even if it's not directly related to the MCU.
    – Zibbobz
    Commented Aug 18, 2014 at 15:53

As an additional answer, it's worth noting that Groot's regenerative abilities are the most realistic in Marvel Comics.

Unlike people who need to eat, the bulk of the volume of (terrestrial) trees actually comes from the air. So if Groot has a hyperactive respiratory system where he can take in massive amounts of carbon rich air quickly, there is no reason he couldn't regenerate from almost any injury. Given that Groot spends time with people who are pumping out quite a lot of carbon, this meets this need.

Add to this the known existence of nitrogen fixing bacteria that are symbiotic with some plants; if Groot had a way of holding these in some way (like in a plant-like digestive tract), he'd be nearly self-sufficient.

In fact, the only thing that Groot would probably need for continued regeneration is a water source and a way to contain it for later use. Now he just needs to learn when it is appropriate to drink and when not to.

Yes you did, I saw you doing it.

The only reason for replanting Groot would be as a way to help regrow some of the components he needs, until he is self-sufficient again, as a single twig wouldn't have everything necessary for self-sufficiency.


How long does it take for Groot to regrow to "full" size?

Approximately six years

(For the purpose of this answer, by "full size" I'm assuming that to mean the same as "adult size".)

In Guardians of the Galaxy (set in 2014), the original Groot heroically gives up his life, and baby Groot sprouts from a twig from the original Groot's body. According to James Gunn, Groot is an “adolescent” in Avengers: Infinity War (set in 2018) and already a “young adult” as of The Guardians of the Galaxy Holiday Special (set in 2025).

screenshot of James Gunn's tweet

Question: Hi James, how old is Groot supposed to be in the special? Kraglin said he’s just a kid when i thought he was a teenager in Infinity War.

James Gunn: That was Adolescent Groot. This is YA Groot.

Since Groot was dusted by Thanos and then brought back five years later in The Blip (2018–2023), we need to subtract those five years from his actual age as of when he was a young adult. So, 2025 minus 2014 equals 11, and 11 minus 5 equals 6.

Therefore, it took Groot approximately six years to grow to his “full” adult size.


The only instances that I have found in my research on the growth patters of Groot indicate that he will grow as a tree does to his full size. I can only fathom to guess that it would require roughly a decade for Groot to be returned to his full potential again however that does not mean that he can not be helpful as an adolescent or even a young adult tree in just a few years.

  • 2
    Why do you think it takes a decade rather than a shorter or longer amount of time? And what about the second bullet point?
    – Null
    Commented Jan 4, 2015 at 1:15

He does not seem to grow at the speed of a tree, because when Gamora cut off his arms they regrew pretty fast.

It would probably take a few weeks to months for his entire body to regrow.

  • This technically answers the question, but is a little bare-bones. It could use better reference to the specific scene (though you can't yet post images or links as a new user) and a bit more detail, such as how long it took him to regrow after getting his arm cut off, and how you came to the conclusion about how long it would take for his whole body to regrow. I removed the personal conjecture part of your answer, since it's actually based on observation - which is what a good answer needs.
    – Zibbobz
    Commented Jan 26, 2015 at 21:13

Groot's growth rate is equivalent to rate at which a given author needs him to be a certain size in order for him to serve the story.

  • 4
    Any reason why your "answer" is more accurate than the accepted answer with plenty of canon sources as support?
    – Edlothiad
    Commented Sep 22, 2017 at 19:21

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