Use the group attached_nodes

mods/default/init.lua

@@ -853,7 +853,7 @@ minetest.register_node("default:junglegrass", {
 	wield_image = "default_junglegrass.png",
 	paramtype = "light",
 	walkable = false,
-	groups = {snappy=3,flammable=2},
+	groups = {snappy=3,flammable=2,attached_node=1},
 	sounds = default.node_sound_leaves_defaults(),
 })
 
@@ -957,7 +957,7 @@ minetest.register_node("default:rail", {
                 -- but how to specify the dimensions for curved and sideways rails?
                 fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
 	},
-	groups = {bendy=2,snappy=1,dig_immediate=2},
+	groups = {bendy=2,snappy=1,dig_immediate=2,attached_node=1},
 })
 
 minetest.register_node("default:ladder", {
@@ -1142,7 +1142,7 @@ minetest.register_node("default:torch", {
 		wall_bottom = {-0.1, -0.5, -0.1, 0.1, -0.5+0.6, 0.1},
 		wall_side = {-0.5, -0.3, -0.1, -0.5+0.3, 0.3, 0.1},
 	},
-	groups = {choppy=2,dig_immediate=3,flammable=1},
+	groups = {choppy=2,dig_immediate=3,flammable=1,attached_node=1},
 	legacy_wallmounted = true,
 	sounds = default.node_sound_defaults(),
 })
@@ -1163,7 +1163,7 @@ minetest.register_node("default:sign_wall", {
 		--wall_bottom = <default>
 		--wall_side = <default>
 	},
-	groups = {choppy=2,dig_immediate=2},
+	groups = {choppy=2,dig_immediate=2,attached_node=1},
 	legacy_wallmounted = true,
 	sounds = default.node_sound_defaults(),
 	on_construct = function(pos)
@@ -1545,7 +1545,7 @@ minetest.register_node("default:sapling", {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
 	},
-	groups = {snappy=2,dig_immediate=3,flammable=2},
+	groups = {snappy=2,dig_immediate=3,flammable=2,attached_node=1},
 	sounds = default.node_sound_defaults(),
 })
 
@@ -1576,7 +1576,7 @@ minetest.register_node("default:dry_shrub", {
 	wield_image = "default_dry_shrub.png",
 	paramtype = "light",
 	walkable = false,
-	groups = {snappy=3,flammable=3},
+	groups = {snappy=3,flammable=3,attached_node=1},
 	sounds = default.node_sound_leaves_defaults(),
 	selection_box = {
 		type = "fixed",