diff --git a/src/java/mmm/world/trees/A_WTTreeGenerator.java b/src/java/mmm/world/trees/A_WTTreeGenerator.java
index a58de6e..9d4965c 100644
--- a/src/java/mmm/world/trees/A_WTTreeGenerator.java
+++ b/src/java/mmm/world/trees/A_WTTreeGenerator.java
@@ -70,7 +70,7 @@ public abstract class A_WTTreeGenerator
 
 		protected int getOffset( final int i , final int j , final int k )
 		{
-			return i + this.xSize * ( j + this.height * k );
+			return k + this.zSize * ( j + this.height * i );
 		}
 
 
@@ -149,7 +149,7 @@ public abstract class A_WTTreeGenerator
 		}
 
 
-		private boolean isEmpty( final int x , final int y , final int z )
+		public boolean isEmpty( final int x , final int y , final int z )
 		{
 			if ( x < 0 || x >= this.xSize || y < 0 || y >= this.height || z < 0 || z >= this.zSize ) {
 				return true;
@@ -158,12 +158,148 @@ public abstract class A_WTTreeGenerator
 			return bs == null || bs.getMaterial( ) == Material.AIR;
 		}
 
+
+		public void fixer( final IBlockState log , final int trunkX , final int trunkZ )
+		{
+			final boolean fixedArea[] = new boolean[ this.blocks.length ];
+			for ( int i = 0 ; i < this.xSize ; i++ ) {
+				for ( int j = 0 ; j < this.height ; j++ ) {
+					for ( int k = 0 ; k < this.zSize ; k++ ) {
+						if ( !fixedArea[ this.getOffset( i , j , k ) ] ) {
+							this.fixLeaves( log , trunkX , trunkZ , i , j , k , fixedArea );
+						}
+					}
+				}
+			}
+		}
+
+
+		private void fixLeaves( final IBlockState log , final int trunkX , final int trunkZ , final int x ,
+				final int y , final int z , final boolean[] fixedArea )
+		{
+			final IBlockState bs = this.getBlockState( x , y , z );
+			if ( bs == null || ! ( bs.getBlock( ) instanceof BlockLeaves )
+					|| this.checkSurroundingBlocks( log , x , y , z ) ) {
+				return;
+			}
+
+			final int xd = trunkX < x ? 1 : -1;
+			final int zd = trunkZ < z ? 1 : -1;
+
+			for ( int i = -4 * xd ; i * xd <= 4 ; i += xd ) {
+				final int xi = x + i;
+				if ( xi < 0 || xi >= this.xSize ) {
+					continue;
+				}
+
+				final int sx = i * i;
+				for ( int j = -4 ; j <= 4 ; j++ ) {
+					final int yj = y + j;
+					if ( yj < 0 || yj >= this.height ) {
+						continue;
+					}
+
+					final int sz = sx + j * j;
+					for ( int k = -4 * zd ; k * zd <= 4 ; k += zd ) {
+						if ( i == 0 && j == 0 && k == 0 || sz + k * k >= 16 ) {
+							continue;
+						}
+
+						final int zk = z + k;
+						if ( zk < 0 || zk >= this.zSize || fixedArea[ this.getOffset( xi , yj , zk ) ] ) {
+							continue;
+						}
+
+						final IBlockState state = this.getBlockState( xi , yj , zk );
+						if ( state == null || ! ( state.getBlock( ) instanceof BlockLeaves ) ) {
+							continue;
+						}
+
+						if ( this.isEmpty( xi - 1 , yj , zk ) //
+								|| this.isEmpty( xi + 1 , yj , zk ) //
+								|| this.isEmpty( xi , yj - 1 , zk ) //
+								|| this.isEmpty( xi , yj + 1 , zk ) //
+								|| this.isEmpty( xi , yj , zk - 1 ) //
+								|| this.isEmpty( xi , yj , zk + 1 ) ) {
+							continue;
+						}
+
+						this.addFixAt( log , xi , yj , zk , fixedArea );
+						return;
+					}
+				}
+			}
+		}
+
+
+		private void addFixAt( final IBlockState log , final int x , final int y , final int z ,
+				final boolean[] fixedArea )
+		{
+			this.setBlock( x , y , z , log , E_BlockRequirement.VANILLA );
+			this.setRequirement( x , y , z , E_BlockRequirement.VANILLA );
+			for ( int i = -2 ; i <= 2 ; i++ ) {
+				final int xi = x + i;
+				if ( xi < 0 || xi >= this.xSize ) {
+					continue;
+				}
+				for ( int j = -2 ; j <= 2 ; j++ ) {
+					final int yj = y + j;
+					if ( yj < 0 || yj >= this.height ) {
+						continue;
+					}
+					for ( int k = -2 ; k <= 2 ; k++ ) {
+						final int zk = z + k;
+						if ( zk < 0 || zk >= this.zSize ) {
+							continue;
+						}
+						fixedArea[ this.getOffset( xi , yj , zk ) ] = true;
+					}
+				}
+			}
+		}
+
+
+		private boolean checkSurroundingBlocks( final IBlockState log , final int x , final int y , final int z )
+		{
+			for ( int i = -4 ; i <= 4 ; i++ ) {
+				final int xi = x + i;
+				if ( xi < 0 || xi >= this.xSize ) {
+					continue;
+				}
+
+				final int sx = i * i;
+				for ( int j = -4 ; j <= 4 ; j++ ) {
+					final int yj = y + j;
+					if ( yj < 0 || yj >= this.height ) {
+						continue;
+					}
+
+					final int sz = sx + j * j;
+					for ( int k = -4 ; k <= 4 ; k++ ) {
+						if ( i == 0 && j == 0 && k == 0 || sz + k * k >= 16 ) {
+							continue;
+						}
+
+						final int zk = z + k;
+						if ( zk < 0 || zk >= this.zSize ) {
+							continue;
+						}
+
+						final IBlockState bs = this.getBlockState( xi , yj , zk );
+						if ( bs != null && bs.getBlock( ) == log.getBlock( ) ) {
+							return true;
+						}
+					}
+				}
+			}
+			return false;
+		}
 	}
 
 	private MTree materials;
 
 
-	public A_WTTreeGenerator( final boolean notify , MTree materials )
+	public A_WTTreeGenerator( final boolean notify , final MTree materials )
 	{
 		super( notify );
 		this.materials = materials;
diff --git a/src/java/mmm/world/trees/WTHevea.java b/src/java/mmm/world/trees/WTHevea.java
index c4af913..e4980ca 100644
--- a/src/java/mmm/world/trees/WTHevea.java
+++ b/src/java/mmm/world/trees/WTHevea.java
@@ -48,7 +48,7 @@ public class WTHevea
 		final int leavesHeight = ( rtd.xSize - 1 ) / 2;
 		final int totalLeavesHeight = leavesHeight * 5 / 2;
 		final int trunkBottom = rtd.height - totalLeavesHeight;
-		final int trunkHeight = Math.max( trunkBottom + 1 , rtd.height - ( 1 + rand.nextInt( leavesHeight ) ) );
+		final int trunkHeight = Math.max( trunkBottom + 1 , rtd.height - ( 1 + rand.nextInt( 2 ) ) );
 
 		this.makeLeaves( rtd , rand , leavesHeight , trunkBottom );
 		this.makeTrunk( rtd , rand , leavesHeight , trunkHeight );
diff --git a/src/java/mmm/world/trees/WTHeveaBig.java b/src/java/mmm/world/trees/WTHeveaBig.java
index c5f0613..6ca61cf 100644
--- a/src/java/mmm/world/trees/WTHeveaBig.java
+++ b/src/java/mmm/world/trees/WTHeveaBig.java
@@ -43,6 +43,15 @@ public class WTHeveaBig
 	}
 
 
+	@Override
+	protected void generateTreeBlocks( final RuntimeData rtd , final Random rand )
+	{
+		super.generateTreeBlocks( rtd , rand );
+		final int centre = ( rtd.xSize - 1 ) / 2;
+		rtd.fixer( this.getTreeMaterials( ).LOG.getDefaultState( ) , centre , centre );
+	}
+
+
 	@Override
 	protected void makeTrunk( final RuntimeData rtd , final Random rand , final int leavesHeight ,
 			final int trunkHeight )
@@ -70,12 +79,11 @@ public class WTHeveaBig
 			final int xDir = xAxis ? positive ? 1 : -1 : 0;
 			final int zDir = xAxis ? 0 : positive ? 1 : -1;
 			if ( this.tryBranch( rtd , rand , x , y , z , xDir , zDir , xAxis ? logXAxis : logZAxis ) ) {
-				y += 2 + rand.nextInt( 2 );
+				y += rand.nextInt( 2 );
 				positive = ! ( xAxis || positive ) || xAxis && positive;
 				xAxis = !xAxis;
-			} else {
-				y++;
 			}
+			y++;
 		}
 	}
 
@@ -112,25 +120,12 @@ public class WTHeveaBig
 
 	private boolean canPlaceBranch( final RuntimeData rtd , final int rx , final int ry , final int rz )
 	{
-		for ( int i = -1 ; i <= 1 ; i++ ) {
-			for ( int j = -1 ; j <= 1 ; j++ ) {
-				for ( int k = -1 ; k <= 1 ; k++ ) {
-					final int cx = rx + i;
-					final int cy = ry + j;
-					final int cz = rz + k;
-					if ( cx < 0 || cy < 0 || cz < 0 || cx > rtd.xSize || cy > rtd.height || cz > rtd.zSize ) {
-						return false;
-					}
-
-					final IBlockState bs = rtd.getBlockState( cx , cy , cz );
-					if ( bs == null
-							|| i == 0 && j == 0 && k == 0 && bs.getBlock( ) != this.getTreeMaterials( ).LEAVES ) {
-						return false;
-					}
-				}
-			}
-		}
-		return true;
+		return ! ( rtd.isEmpty( rx - 1 , ry , rz ) //
+				|| rtd.isEmpty( rx + 1 , ry , rz ) //
+				|| rtd.isEmpty( rx , ry - 1 , rz ) //
+				|| rtd.isEmpty( rx , ry + 1 , rz ) //
+				|| rtd.isEmpty( rx , ry , rz - 1 ) //
+				|| rtd.isEmpty( rx , ry , rz + 1 ) );
 	}
 
 }
diff --git a/src/java/mmm/world/trees/WTHeveaMega.java b/src/java/mmm/world/trees/WTHeveaMega.java
index fedf2c3..32e0bce 100644
--- a/src/java/mmm/world/trees/WTHeveaMega.java
+++ b/src/java/mmm/world/trees/WTHeveaMega.java
@@ -90,8 +90,8 @@ public class WTHeveaMega
 		this.makeLeaves( data , rand );
 		this.makeTrunk( data , rand );
 		this.makeBranches( data , rand );
-
 		data.removeCornerLeaves( rand , data.leaves , data.trunkBottom , data.height - 1 , .4f );
+		data.fixer( data.logVertical , data.trunkX , data.trunkZ );
 	}