diff --git a/df_caverns/mod.conf b/df_caverns/mod.conf
index ddc4ebf..f51da08 100644
--- a/df_caverns/mod.conf
+++ b/df_caverns/mod.conf
@@ -1,4 +1,4 @@
 name = df_caverns
 description = Adds vast underground caverns in the style of Dwarf Fortress, complete with underground flora in diverse biomes. Also adds stalactite/stalagmite decorations in the smaller tunnels.
 depends = default, subterrane, df_trees, df_mapitems
-optional_depends = df_farming, ice_sprites, oil, df_underworld_items, magma_conduits, bones_loot, named_waypoints, namegen
\ No newline at end of file
+optional_depends = df_farming, ice_sprites, oil, df_underworld_items, magma_conduits, bones_loot, named_waypoints, namegen, fireflies
\ No newline at end of file
diff --git a/df_caverns/primordial.lua b/df_caverns/primordial.lua
index 75e20b8..da76efa 100644
--- a/df_caverns/primordial.lua
+++ b/df_caverns/primordial.lua
@@ -143,6 +143,11 @@ local c_ivy = minetest.get_content_id("df_primordial_items:jungle_ivy")
 local c_root_2 = minetest.get_content_id("df_primordial_items:jungle_roots_2")
 local c_root_1 = minetest.get_content_id("df_primordial_items:jungle_roots_1")
 
+local c_fireflies
+if minetest.get_modpath("fireflies") then
+	c_fireflies = minetest.get_content_id("fireflies:firefly")
+end
+
 local jungle_cavern_floor = function(abs_cracks, humidity, vi, area, data, data_param2)
 	local ystride = area.ystride
 	local humidityfactor = humidity/100
@@ -161,6 +166,13 @@ local jungle_cavern_floor = function(abs_cracks, humidity, vi, area, data, data_
 	elseif rand < 0.3 then
 		data[vi+ystride] = jungle_plants[math.random(1,#jungle_plants)]
 	end
+	
+	if c_fireflies and math.random() < 0.01 then
+		local firefly_vi = vi + ystride * math.random(1, 5)
+		if data[firefly_vi] == c_air then
+			data[firefly_vi] = c_fireflies
+		end
+	end
 end
 
 local jungle_cavern_ceiling = function(abs_cracks, vi, area, data, data_param2)
@@ -222,6 +234,13 @@ local jungle_warren_floor = function(abs_cracks, vi, area, data, data_param2)
 	elseif abs_cracks < 1 then
 		data[vi] = c_dirt
 	end
+	
+	if c_fireflies and math.random() < 0.005 then
+		local firefly_vi = vi + ystride * math.random(1, 5)
+		if data[firefly_vi] == c_air then
+			data[firefly_vi] = c_fireflies
+		end
+	end
 end
 ---------------------------------------------------------------------------------------------------------
 
@@ -322,7 +341,7 @@ local decorate_primordial = function(minp, maxp, seed, vm, node_arrays, area, da
 		local jungle = nvals_cave[vi] < 0
 		if jungle then
 			data[vi] = c_plant_matter
-			minetest.get_node_timer(area:position(vi)):start(math.random(10, 60))
+			minetest.get_node_timer(area:position(vi)):start(math.random(30, 120))
 		else
 			data[vi] = c_mycelial_dirt
 			if math.random() < 0.025 then
diff --git a/df_caverns/shared.lua b/df_caverns/shared.lua
index 52ce208..40411e5 100644
--- a/df_caverns/shared.lua
+++ b/df_caverns/shared.lua
@@ -235,6 +235,9 @@ df_caverns.is_ground_content = function(c_node)
 	end
 	dfcaverns_nodes[minetest.get_content_id("default:ice")] = true -- needed for nethercap cavern water covering
 	dfcaverns_nodes[minetest.get_content_id("oil:oil_source")] = true -- needed for blackcap oil slicks
+	if minetest.get_modpath("fireflies") then
+		dfcaverns_nodes[minetest.get_content_id("fireflies:firefly")] = true -- used in the primordial caverns
+	end
 	dfcaverns_mods = nil
 	return not dfcaverns_nodes[c_node]
 end
\ No newline at end of file
diff --git a/df_primordial_items/jungle_nodes.lua b/df_primordial_items/jungle_nodes.lua
index eef4c5f..3c38d05 100644
--- a/df_primordial_items/jungle_nodes.lua
+++ b/df_primordial_items/jungle_nodes.lua
@@ -283,7 +283,14 @@ minetest.register_node("df_primordial_items:plant_matter", {
 	paramtype = "light",
 	groups = {crumbly = 3, soil = 1},
 	sounds = default.node_sound_dirt_defaults(),
-	on_timer = function(pos)
+	on_timer = function(pos, elapsed)
+		if elapsed > 130 then
+			-- the timer triggered more than ten seconds after it was suppposed to,
+			-- it may have been in an unloaded block. Rather than have all the timers
+			-- go off at once now that the block's loaded, stagger them out again.
+			minetest.get_node_timer(pos):start(math.random(10, 120))
+			return
+		end
 		if minetest.find_node_near(pos, 1, {"air"}) == nil then
 			minetest.set_node(pos, {name="df_primordial_items:packed_roots"})
 		end