diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9671fbf5..6868d958 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,11 @@ This is the rolling changelog for TShock for Terraria. Use past tense when addin
   * Do not forget to sign every line you change with your name. (@hakusaro)
   * If there is no section called "Upcoming changes" below this line, please add one with `## Upcoming changes` as the first line, and then a bulleted item directly after with the first change.
 
+
+## Upcoming changes
+* Improved the `/grow` command to reduce code duplication, use `TileID` constants for less ambiguous types. (@drunderscore)
+* Fixed item dupe via /logout & NPC. (@Terrarxxn)
+
 ## TShock 4.5.13
 * Added hook `GetDataHandlers.OnReleaseNpc` to handling ReleaseNPC packet and a bouncer to stops unregistered and logged out players on SSC servers from releasing critters NPC. The bouncer has additional filter to stops players who tried to release different critter using crafted packet, e.g. using bunny item to release golden bunny. (@tru321)
 * Added filter in `GetDataHandlers.HandleCatchNpc` that stops unregistered and logged out players on SSC servers to catch critters. (@tru321)
diff --git a/TShockAPI/Commands.cs b/TShockAPI/Commands.cs
index ff0ed1ac..6b7f3259 100644
--- a/TShockAPI/Commands.cs
+++ b/TShockAPI/Commands.cs
@@ -911,6 +911,12 @@ namespace TShockAPI
 				return;
 			}
 
+			if (args.Player.TPlayer.talkNPC != -1)
+			{
+				args.Player.SendErrorMessage("Please close NPC windows before logging out.");
+				return;
+			}
+
 			args.Player.Logout();
 			args.Player.SendSuccessMessage("You have been successfully logged out of your account.");
 			if (Main.ServerSideCharacter)
@@ -6326,7 +6332,7 @@ namespace TShockAPI
 
 		public static void Grow(CommandArgs args)
 		{
-			bool growevilAmb = args.Player.HasPermission(Permissions.growevil);
+			bool canGrowEvil = args.Player.HasPermission(Permissions.growevil);
 			string subcmd = args.Parameters.Count == 0 ? "help" : args.Parameters[0].ToLower();
 
 			var name = "Fail";
@@ -6368,284 +6374,163 @@ namespace TShockAPI
 					}
 					break;
 
-				case "basic":
-					for (int i = x - 2; i < x + 3; i++)
+					bool rejectCannotGrowEvil()
 					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 2;
-						Main.tile[i, y].wall = 0;
+						if(!canGrowEvil)
+						{
+							args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+							return false;
+						}
+
+						return true;
 					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.GrowTree(x, y);
-					name = "Basic Tree";
+
+					bool prepareAreaForGrow(ushort groundType = TileID.Grass, bool evil = false)
+					{
+						if(evil && !rejectCannotGrowEvil())
+							return false;
+
+						for (var i = x - 2; i < x + 3; i++)
+						{
+							Main.tile[i, y].active(true);
+							Main.tile[i, y].type = groundType;
+							Main.tile[i, y].wall = WallID.None;
+						}
+						Main.tile[x, y - 1].wall = WallID.None;
+
+						return true;
+					}
+
+					bool growTree(ushort groundType, string fancyName, bool evil = false)
+					{
+						if(!prepareAreaForGrow(groundType, evil))
+							return false;
+						WorldGen.GrowTree(x, y);
+						name = fancyName;
+
+						return true;
+					}
+
+					bool growTreeByType(ushort groundType, string fancyName, ushort typeToPrepare = 2, bool evil = false)
+					{
+						if(!prepareAreaForGrow(typeToPrepare, evil))
+							return false;
+						WorldGen.TryGrowingTreeByType(groundType, x, y);
+						name = fancyName;
+
+						return true;
+					}
+
+					bool growPalmTree(ushort sandType, ushort supportingType, string properName, bool evil = false)
+					{
+						if(evil && !rejectCannotGrowEvil())
+							return false;
+
+						for (int i = x - 2; i < x + 3; i++)
+						{
+							Main.tile[i, y].active(true);
+							Main.tile[i, y].type = sandType;
+							Main.tile[i, y].wall = WallID.None;
+						}
+						for (int i = x - 2; i < x + 3; i++)
+						{
+							Main.tile[i, y + 1].active(true);
+							Main.tile[i, y + 1].type = supportingType;
+							Main.tile[i, y + 1].wall = WallID.None;
+						}
+
+						Main.tile[x, y - 1].wall = WallID.None;
+						WorldGen.GrowPalmTree(x, y);
+
+						name = properName;
+
+						return true;
+					}
+
+				case "basic":
+					growTree(TileID.Grass, "Basic Tree");
 					break;
 
 				case "boreal":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 147;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.GrowTree(x, y);
-					name = "Boreal Tree";
+					growTree(TileID.SnowBlock, "Boreal Tree");
 					break;
 
 				case "mahogany":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 60;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.GrowTree(x, y);
-					name = "Rich Mahogany";
+					growTree(TileID.JungleGrass, "Rich Mahogany");
 					break;
 
 				case "sakura":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 2;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(596, x, y);
-					name = "Sakura Tree";
+					growTreeByType(TileID.VanityTreeSakura, "Sakura Tree");
 					break;
 
 				case "willow":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 2;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(616, x, y);
-					name = "Willow Tree";
+					growTreeByType(TileID.VanityTreeYellowWillow, "Willow Tree");
 					break;
 
 				case "shadewood":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 199;
-							Main.tile[i, y].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowTree(x, y);
-						name = "Shadewood tree";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growTree(TileID.CrimsonGrass, "Shadewood Tree", true))
+						return;
 					break;
 
 				case "ebonwood":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 23;
-							Main.tile[i, y].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowTree(x, y);
-						name = "Ebonwood Tree";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growTree(TileID.CorruptGrass, "Ebonwood Tree", true))
+						return;
 					break;
 
 				case "pearlwood":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 109;
-							Main.tile[i, y].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowTree(x, y);
-						name = "Pearlwood Tree";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growTree(TileID.HallowedGrass, "Pearlwood Tree", true))
+						return;
 					break;
 
 				case "palm":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 53;
-						Main.tile[i, y].wall = 0;
-					}
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y + 1].active(true);
-						Main.tile[i, y + 1].type = 397;
-						Main.tile[i, y + 1].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.GrowPalmTree(x, y);
-					name = "Desert Palm";
+					growPalmTree(TileID.Sand, TileID.HardenedSand, "Desert Palm");
 					break;
 
 				case "hallowpalm":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 116;
-							Main.tile[i, y].wall = 0;
-						}
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y + 1].active(true);
-							Main.tile[i, y + 1].type = 402;
-							Main.tile[i, y + 1].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowPalmTree(x, y);
-						name = "Hallow Palm";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growPalmTree(TileID.Pearlsand, TileID.HallowHardenedSand, "Hallow Palm", true))
+						return;
 					break;
 
 				case "crimsonpalm":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 234;
-							Main.tile[i, y].wall = 0;
-						}
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y + 1].active(true);
-							Main.tile[i, y + 1].type = 399;
-							Main.tile[i, y + 1].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowPalmTree(x, y);
-						name = "Crimson Palm";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growPalmTree(TileID.Crimsand, TileID.CrimsonHardenedSand, "Crimson Palm", true))
+						return;
 					break;
 
 				case "corruptpalm":
-					if (growevilAmb)
-					{
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y].active(true);
-							Main.tile[i, y].type = 112;
-							Main.tile[i, y].wall = 0;
-						}
-						for (int i = x - 2; i < x + 3; i++)
-						{
-							Main.tile[i, y + 1].active(true);
-							Main.tile[i, y + 1].type = 398;
-							Main.tile[i, y + 1].wall = 0;
-						}
-						Main.tile[x, y - 1].wall = 0;
-						WorldGen.GrowPalmTree(x, y);
-						name = "Corruption Palm";
-					}
-					else args.Player.SendErrorMessage("You do not have permission to grow this tree type");
+					if(!growPalmTree(TileID.Ebonsand, TileID.CorruptHardenedSand, "Corruption Palm", true))
+						return;
 					break;
 
 				case "topaz":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(583, x, y);
-					name = "Topaz Gemtree";
+					growTreeByType(TileID.TreeTopaz, "Topaz Gemtree", 1);
 					break;
 
 				case "amethyst":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(584, x, y);
-					name = "Amethyst Gemtree";
+					growTreeByType(TileID.TreeAmethyst, "Amethyst Gemtree", 1);
 					break;
 
 				case "sapphire":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(585, x, y);
-					name = "Sapphire Gemtree";
+					growTreeByType(TileID.TreeSapphire, "Sapphire Gemtree", 1);
 					break;
 
 				case "emerald":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(586, x, y);
-					name = "Emerald Gemtree";
+					growTreeByType(TileID.TreeEmerald, "Emerald Gemtree", 1);
 					break;
 
 				case "ruby":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(587, x, y);
-					name = "Ruby Gemtree";
+					growTreeByType(TileID.TreeRuby, "Ruby Gemtree", 1);
 					break;
 
 				case "diamond":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(588, x, y);
-					name = "Diamond Gemtree";
+					growTreeByType(TileID.TreeDiamond, "Diamond Gemtree", 1);
 					break;
 
 				case "amber":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 1;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
-					WorldGen.TryGrowingTreeByType(589, x, y);
-					name = "Amber Gemtree";
+					growTreeByType(TileID.TreeAmber, "Amber Gemtree", 1);
 					break;
 
 				case "cactus":
-					Main.tile[x, y].type = 53;
+					Main.tile[x, y].type = TileID.Sand;
 					WorldGen.GrowCactus(x, y);
 					name = "Cactus";
 					break;
@@ -6653,19 +6538,13 @@ namespace TShockAPI
 				case "herb":
 					Main.tile[x, y].active(true);
 					Main.tile[x, y].frameX = 36;
-					Main.tile[x, y].type = 83;
+					Main.tile[x, y].type = TileID.MatureHerbs;
 					WorldGen.GrowAlch(x, y);
 					name = "Herb";
 					break;
 
 				case "mushroom":
-					for (int i = x - 2; i < x + 3; i++)
-					{
-						Main.tile[i, y].active(true);
-						Main.tile[i, y].type = 70;
-						Main.tile[i, y].wall = 0;
-					}
-					Main.tile[x, y - 1].wall = 0;
+					prepareAreaForGrow(TileID.MushroomGrass);
 					WorldGen.GrowShroom(x, y);
 					name = "Glowing Mushroom Tree";
 					break;