diff --git a/.luacheckrc b/.luacheckrc
index d999c36..3664db6 100644
--- a/.luacheckrc
+++ b/.luacheckrc
@@ -9,7 +9,7 @@ globals = {
 
 read_globals = {
     string = {fields = {"split"}},
-    table = {fields = {"copy", "getn"}},
+    table = {fields = {"copy", "getn", "shuffle"}},
 
     -- Builtin
     "vector", "ItemStack",
diff --git a/mods/ebiometrees/sapling.lua b/mods/ebiometrees/sapling.lua
index 7249fcc..34ca57b 100644
--- a/mods/ebiometrees/sapling.lua
+++ b/mods/ebiometrees/sapling.lua
@@ -1,8 +1,13 @@
 ebiometrees = {}
+ebiometrees.directions = {
+  up     = vector.new( 0,  1,  0),
+  down   = vector.new( 0, -1,  0),
+  north  = vector.new( 0,  0,  1),
+  east   = vector.new( 1,  0,  0),
+  south  = vector.new( 0,  0, -1),
+  west   = vector.new(-1,  0,  0)
+}
 
-function ebiometrees.is_leaves_can_grow_here(pos)
-  return false
-end
 
 function ebiometrees.grow_closure(nextstage)
   local function growtree(pos)
@@ -11,7 +16,38 @@ function ebiometrees.grow_closure(nextstage)
   return growtree
 end
 
-function ebiometrees.leaves_grower(leaves_name)
+function ebiometrees.where_to_grow_trunk_closure(grow_preferences, leaves_name)
+  local function where_to_grow_trunk(pos)
+    for _, directions in ipairs(grow_preferences)
+    do
+      table.shuffle(directions)
+      local candidate_dir = directions[1]
+      local candidate = vector.copy(pos):add(candidate_dir)
+      local node = minetest.get_node_or_nil(candidate)
+      if node and node.name == leaves_name
+      then
+        return candidate
+      end
+    end
+  end
+  return where_to_grow_trunk
+end
+
+function ebiometrees.grow_trunk_closure(trunk_terminal_name, grow_preferences, leaves_name)
+  local function grow_trunk(pos)
+    local where = ebiometrees.where_to_grow_trunk_closure(
+      grow_preferences, leaves_name
+    )
+    local there = where(pos)
+    if there
+    then
+      minetest.set_node(there, {name=trunk_terminal_name})
+    end
+  end
+  return grow_trunk
+end
+
+function ebiometrees.grow_leaves_closure(leaves_name)
   local function grow_leaves(pos)
     local free_node = minetest.find_node_near(pos, 1, "air")
     if free_node
@@ -23,6 +59,27 @@ function ebiometrees.leaves_grower(leaves_name)
   return grow_leaves
 end
 
+
+function ebiometrees.tree_grower(leaves_name, grow_preferences, terminal_name, nextstage, age_max)
+  local grow_trunk =  ebiometrees.grow_trunk_closure(terminal_name, grow_preferences, leaves_name)
+  local grow_leaves = ebiometrees.grow_leaves_closure(leaves_name)
+  local function grow_tree(pos)
+    local meta = minetest.get_meta(pos)
+    meta:set_int("ebiometrees:age", meta:get_int("ebiometrees:age")+1)
+    grow_trunk(pos)
+    grow_leaves(pos)
+    if nextstage
+    then
+      if meta:get_int("ebiometrees:age") > age_max
+      then
+        minetest.set_node(pos, {name=nextstage})
+      end
+    end
+    return true
+  end
+  return grow_tree
+end
+
 function ebiometrees.root_sapling(pos)
   minetest.set_node(pos, {name="ebiome:oak_sprout"})
   return false
diff --git a/mods/ebiometrees/tree.lua b/mods/ebiometrees/tree.lua
index e6515c9..be0b012 100644
--- a/mods/ebiometrees/tree.lua
+++ b/mods/ebiometrees/tree.lua
@@ -1,5 +1,8 @@
 local function growth_timer(pos)
   minetest.get_node_timer(pos):start(3)
+  local meta = minetest.get_meta(pos)
+  meta:set_int("ebiometrees:age", 0)
+  meta:mark_as_private("ebiometrees:age")
 end
 
 
@@ -61,6 +64,7 @@ function ebiometrees.register_tree(modname, basename, data)
   -- registers corresponding trunk nodes
   local trunk_groups = table.copy(data.groups)
   trunk_groups.choppy = 2 -- TODO: customizations
+  trunk_groups.treetrunk = 1
   local trunk_types = {"growing", "normal"}
   local trunk_subtypes = {"terminal", "straight", "corner",
     "tjunction", "t2junction", "xjunction",
@@ -137,8 +141,21 @@ function ebiometrees.register_tree(modname, basename, data)
       }
       if trunk_type == "growing"
         then
-          nodespec.on_timer = ebiometrees.leaves_grower(
-            modname..":"..basename.."_leaves")
+          nodespec.on_timer = ebiometrees.tree_grower(
+            modname..":"..basename.."_leaves",
+            {
+              {ebiometrees.directions.up},
+              {
+                ebiometrees.directions.north,
+                ebiometrees.directions.east,
+                ebiometrees.directions.south,
+                ebiometrees.directions.west
+              }
+            },
+            modname..":"..basename.."_trunk_growing_terminal",
+            modname..":"..basename.."_trunk_normal_"..trunk_subtype,
+            20
+          )
       end
       minetest.register_node(
         modname..":"..basename.."_trunk_"..trunk_type.."_"..trunk_subtype,