diff --git a/API.txt b/API.txt
index c033926..13cab6a 100644
--- a/API.txt
+++ b/API.txt
@@ -184,7 +184,7 @@ defined like so:
 
 grow_plants = function(gdelay, gchance, gplant, gresult, dry_early_node,
 	grow_nodes, facedir, need_wall, grow_vertically, height_limit,
-	ground_nodes, grow_function)
+	ground_nodes, grow_function, seed_diff)
 
 gdelay:		Passed as the ABM "interval" parameter, as with spawning.
 gchance:	Passed as the ABM "chance" parameter.
@@ -221,21 +221,20 @@ ground_nodes:	What nodes should be treated as "the ground" below a
 		as the grow_nodes table, but might also include, for
 		example, water or some other surrounding material.
 		Defaults to "default:dirt_with_grass".
-grow_function:	Execute the named function (which must be supplied as just
-		the name of the function as a string) when growing this
-		node, rather than using the method provided by the default
-		growing code.  Note that if this is specified, only the
-		gdelay, gchance, and gplant variables will be used, the
-		rest will be ignored by the growing ABM.  You can still
-		read them from within the function if you need to.  The
-		function will be passed two parameters in order:  The
-		position of the node to be "grown" (in the usual table
-		format), and the Perlin noise value at the location in
-		question.
-seed_diff:	The Perlin seed diff to be use to calculate the noise 
-		value given to the above grow_function.  Should be the
-		same as the seed diff used when first spawning the plant
-		that's being grown.
+grow_function:	String indicating what function to use to grow the plant, if
+		any, or a table with an L-Systems tree model, or nil.  If it's
+		nil,  If it's nil, a regular plant will be inserted in place 
+		of the one being grown, per the above variables.  If it's a
+		string, the function named therein is executed and passed a
+		parameter for the current position, followed by the "can grow
+		here" and temperature map Perlin values at that location.  If
+		it's a table, the tree described by that table is spawned at
+		the current position.  In both cases, all parameters from
+		gresult to ground_nodes are ignored.
+seed_diff:	The Perlin seed diff to be use to calculate the first noise 
+		value given to the above grow_function.  Should be the same as
+		the seed diff used when first spawning the plant that's being
+		grown.
 
 -----
 
diff --git a/plants_lib/init.lua b/plants_lib/init.lua
index 8786691..8f89b7e 100644
--- a/plants_lib/init.lua
+++ b/plants_lib/init.lua
@@ -258,8 +258,14 @@ function plantslib:grow_plants(
 				local perlin2 = minetest.env:get_perlin(temperature_seeddiff, temperature_octaves, temperature_persistence, temperature_scale)
 				local noise1 = perlin1:get2d({x=p_top.x, y=p_top.z})
 				local noise2 = perlin2:get2d({x=p_top.x, y=p_top.z})
-				minetest.log("verbose", "Call function: "..grow_function.."("..dump(pos)..","..noise1..","..noise2..")")
-				assert(loadstring(grow_function.."("..dump(pos)..","..noise1..","..noise2..")"))()
+				if type(grow_function) == "table" then
+					minetest.log("verbose", "Grow sapling into tree at "..dump(pos))
+					minetest.env:remove_node(pos)
+					minetest.env:spawn_tree(pos, grow_function)
+				else
+					minetest.log("verbose", "Call function: "..grow_function.."("..dump(pos)..","..noise1..","..noise2..")")
+					assert(loadstring(grow_function.."("..dump(pos)..","..noise1..","..noise2..")"))()
+				end
 			end
 		end
 	})