diff --git a/README b/README
index 5b1d0de..ee7ae82 100644
--- a/README
+++ b/README
@@ -16,6 +16,11 @@ cotton, and waterlilies only spawn when there at least a signficant amount of
 light.  Seaweed will grow only in dimly-lit areas.  Jungle grass and poison ivy 
 also grow in the daytime, but require less light than flowers.
 
+Growing of jungle grass and poison ivy will only occur for plants that are on 
+the same surface that is necessary for them to spawn on, so they won't grow if 
+placed on e.g. cobble or homedecor flower pot, etc.  This doesn't affect 
+wall-climbing poison ivy, since it uses a different growth pattern.
+
 All plants use perlin noise to keep where they grow under control - no more 
 random spread of plants!  In addition, the density of the plants in any region 
 they appear in has been fixed and brought under control.