Do Fumaroles respawn?

[Quemark]

My Fumarole Biome is very small because it is old server.

It means it has not enough amounts of fumarole.

Now all of fumaroles in my server is destroied by Mega-Blight, so there are no more Miasma.

Is there any way to respawn fumaroles?

[Kacpert25]

3 hours ago, Quemark said:

Is there any way to respawn fumaroles?

You can't do this without using commands. They don't respawn naturally. But geothermites act like fumaroles. So you can use them to produce miasma.

[Quemark]

41 minutes ago, Kacpert25 said:

You can't do this without using commands. They don't respawn naturally. But geothermites act like fumaroles. So you can use them to produce miasma.

But I havn't see geothermites in my server. I don't know what's wrong with this server...

[Jakepeng99]

4 hours ago, Kacpert25 said:

You can't do this without using commands. They don't respawn naturally. But geothermites act like fumaroles. So you can use them to produce miasma.

Idk if they spawn in old worlds. I don’t think they do.

They are also how fumaroles are meant to respawn.

[Kacpert25]

3 hours ago, Jakepeng99 said:

Idk if they spawn in old worlds. I don’t think they do.

6 hours ago, Quemark said:

But I havn't see geothermites in my server. I don't know what's wrong with this server...

Goethermite spawners don't work on biome generated on old worlds between 18/09/2025 - 07/01/2026.
Now if you were to enter any old world that you hadn't entered between the given time period, the generated fumarole biome would have working Geothermite spawners.

Luckily, someone created a custom command that allows you to spawn this biome with working geothermite spawners.

Unfortunately, the command currently doesn't take into account working regrowth on the fumarole biome. However, the command's author intends to fix this soon or later.

[Quemark]

17 hours ago, Kacpert25 said:

Goethermite spawners don't work on biome generated on old worlds between 18/09/2025 - 07/01/2026.
Now if you were to enter any old world that you hadn't entered between the given time period, the generated fumarole biome would have working Geothermite spawners.

Luckily, someone created a custom command that allows you to spawn this biome with working geothermite spawners.

Unfortunately, the command currently doesn't take into account working regrowth on the fumarole biome. However, the command's author intends to fix this soon or later.

Actually I tried that method, but I don't think it's work for me.
Also I don't know how can I remove old fumarole biome too... ☜ I guess this it the problem
 

Edited February 10 by Quemark

[Kacpert25]

4 hours ago, Quemark said:

Actually I tried that method, but I don't think it's work for me.
Also I don't know how can I remove old fumarole biome too... ☜ I guess this it the problem

Simple Map Editor Fix Mod:
https://steamcommunity.com/sharedfiles/filedetails/?id=1848571133

Numpad 7 responsible for the old ocean in the caves places a void tile, which works 100% as it should.

Just remember to remove the Ripple/Mega Blight spawner from the old fumarole biome as well.

Edited February 10 by Kacpert25

[Adgycarp]

On 2/9/2026 at 7:39 PM, Kacpert25 said:

Unfortunately, the command currently doesn't take into account working regrowth on the fumarole biome. However, the command's author intends to fix this soon or later.

So about that.. I've been fiddling around with this, and from what i've found so far: It seems that on any retrofitted world with fumarole biome, the boulder tree regrowth does not happen, AT ALL.

Have you perhaps seen/experienced by yourself if the boulderboughs would regrow on your own retrofitted worlds? Regardless of the used method for retrofitting (vanilla, or modfix, or custom spawn command).

Because I can't get the regrowth to work for the life ofr me, even on the entirely vanilla retrofit worlds. Whereas newly generated worlds seem to have no issue regrowing them...

[Lovens]

4 hours ago, Adgycarp said:

So about that.. I've been fiddling around with this, and from what i've found so far: It seems that on any retrofitted world with fumarole biome, the boulder tree regrowth does not happen, AT ALL.

Have you perhaps seen/experienced by yourself if the boulderboughs would regrow on your own retrofitted worlds? Regardless of the used method for retrofitting (vanilla, or modfix, or custom spawn command).

Because I can't get the regrowth to work for the life ofr me, even on the entirely vanilla retrofit worlds. Whereas newly generated worlds seem to have no issue regrowing them...

It does work for me but is slow as heck. In a retrofitted Fumarole I really located all existing boulderbough trees into the ruins. Ever since only two new boulderbough trees appeared in the biome. It's been about 5 years since we retrofitted the biome (happened automatically) and it seems like the regrowth rate is about 1 tree in two years. So much for the desolation regrowth wow Klei. Pesky geothermites are present there as well. We didn't fight the shadow sentipede yet (shadow rifts are not active yet) but even if we wanted to we'd have no way of doing so because we barely had any trees there to begin with and the new ones barely appear. There was room in the void for the bigger Fumarole biome but all we got is this ridiculous small biome. New worlds have over 100 of these trees in their Fumaroles. We barely got over 30 with additional couple from regrowth and 3 from the Greater depths worm. 

[Adgycarp]

37 minutes ago, Lovens said:

It does work for me but is slow as heck. In a retrofitted Fumarole I really located all existing boulderbough trees into the ruins. Ever since only two new boulderbough trees appeared in the biome. It's been about 5 years since we retrofitted the biome (happened automatically) and it seems like the regrowth rate is about 1 tree in two years. So much for the desolation regrowth wow Klei. Pesky geothermites are present there as well. We didn't fight the shadow sentipede yet (shadow rifts are not active yet) but even if we wanted to we'd have no way of doing so because we barely had any trees there to begin with and the new ones barely appear. There was room in the void for the bigger Fumarole biome but all we got is this ridiculous small biome. New worlds have over 100 of these trees in their Fumaroles. We barely got over 30 with additional couple from regrowth and 3 from the Greater depths worm. 

oh. that helps to know.

From checking the code it becomes apparant why these things barely spawn at all. It's because of the biome's small size when retro fitted

from tuning.lua: 

        -- Rock trees only have desolation regrowth
           DESOLATION_RESPAWN_TIME = total_day_time * 50

So they do not regrow from offspring. only through desolation regrowth. And the latter only happens when there are none of 'em in the nearby area.
It takes 50 days before the game even considers spawning a new one.

and the conditions to pass the check for desolation respawning are quite strict:
from desolationspawner.lua:
local SEARCH_RADIUS = 50
local BASE_RADIUS = 20 not relevant
local EXCLUDE_RADIUS = 3

exclude radius, it will fail if anything is in this radius (i think it's the radius of a wall unit, not 100% sure)

search radius, it will search in this radius if the same object that was to be regrown is already in there. The check fails if it finds one.

It's actually a miracle that you had 2 of those trees regrow in that tiny biome.

so it's not bugged like i thought initially. the regrowing conditions are too narrow, and the biome is too tiny for regrowing any decent amount over time.

This would easily be improved if the regrowing conditions for Boulderbough specifically would be tweaked. Or if there was a larger retrofitted biome. The latter should be easily possible, given the sheer volume of empty room in your average cave worldgen 

1 hour ago, Lovens said:

There was room in the void for the bigger Fumarole biome but all we got is this ridiculous small biome.

Indeed↑

 

 

[Quemark]

15 hours ago, Kacpert25 said:

Simple Map Editor Fix Mod:
https://steamcommunity.com/sharedfiles/filedetails/?id=1848571133

Numpad 7 responsible for the old ocean in the caves places a void tile, which works 100% as it should.

Just remember to remove the Ripple/Mega Blight spawner from the old fumarole biome as well.

Oh wow, thanks! You are very kind. I'll try this very soon. 

[Kacpert25]

13 hours ago, Adgycarp said:

so it's not bugged like i thought initially. the regrowing conditions are too narrow, and the biome is too tiny for regrowing any decent amount over time.

So if a biome is too small for desolation regrowth to work well, would spawning that biome multiple times so that they merge into one large one make regrowth work?

[Adgycarp]

1 hour ago, Kacpert25 said:

So if a biome is too small for desolation regrowth to work well, would spawning that biome multiple times so that they merge into one large one make regrowth work?

Probably, yeah. Or using mods to tweak those earlier mentioned numbers.

to set boulderbough regrowth to fastest in settings would make the regrowth timer 3x shorter, but it will not change the small radius preventing regrowing larger numbers.

[Lovens]

23 hours ago, Adgycarp said:

oh. that helps to know.

From checking the code it becomes apparant why these things barely spawn at all. It's because of the biome's small size when retro fitted

from tuning.lua: 

        -- Rock trees only have desolation regrowth
           DESOLATION_RESPAWN_TIME = total_day_time * 50

So they do not regrow from offspring. only through desolation regrowth. And the latter only happens when there are none of 'em in the nearby area.
It takes 50 days before the game even considers spawning a new one.

and the conditions to pass the check for desolation respawning are quite strict:
from desolationspawner.lua:
local SEARCH_RADIUS = 50
local BASE_RADIUS = 20 not relevant
local EXCLUDE_RADIUS = 3

exclude radius, it will fail if anything is in this radius (i think it's the radius of a wall unit, not 100% sure)

search radius, it will search in this radius if the same object that was to be regrown is already in there. The check fails if it finds one.

It's actually a miracle that you had 2 of those trees regrow in that tiny biome.

so it's not bugged like i thought initially. the regrowing conditions are too narrow, and the biome is too tiny for regrowing any decent amount over time.

This would easily be improved if the regrowing conditions for Boulderbough specifically would be tweaked. Or if there was a larger retrofitted biome. The latter should be easily possible, given the sheer volume of empty room in your average cave worldgen 

Indeed↑

 

 

Can you please put this as a bug in the Bug tracker thread? Seems like it would be better for devs to see it there, they might not notice it. The regrowth should not be that bad in retrofitted worlds, if anything it should be the opposite to make up for our small biome sizes.

[Quemark]

On 2/11/2026 at 1:44 AM, Kacpert25 said:

Simple Map Editor Fix Mod:
https://steamcommunity.com/sharedfiles/filedetails/?id=1848571133

Numpad 7 responsible for the old ocean in the caves places a void tile, which works 100% as it should.

Just remember to remove the Ripple/Mega Blight spawner from the old fumarole biome as well.

Heey I did it, and it work! Thanks again! 

[Adgycarp]

14 hours ago, Lovens said:

Can you please put this as a bug in the Bug tracker thread? Seems like it would be better for devs to see it there, they might not notice it. The regrowth should not be that bad in retrofitted worlds, if anything it should be the opposite to make up for our small biome sizes.

They won't notice it in the bug tracker either 🤷‍♀️

I do aggree personally, but to me it's not important enough to report as bug...

However if you wish to report it from your side, feel free to. And if you want to, feel free to quote the thing I said earlier(about the desolation growth), or on other reports.
edit, Oh and it might be good to mention the thing you said that's in my reply
it is imo more like a design flaw or oversight. But in terms of impact to gameplay, that might as well be a bug ^_^

Edited February 12 by Adgycarp
additional comments