Think I've fixed the leak...

But I think it's showing up bugs elsewhere that need to be fixed.

src/Perspex.Controls/Control.cs

@@ -312,6 +312,12 @@ namespace Perspex.Controls
         /// <inheritdoc/>
         IStyleHost IStyleHost.StylingParent => (IStyleHost)InheritanceParent;
 
+        /// <inheritdoc/>
+        void ILogical.NotifyDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
+        {
+            this.OnDetachedFromLogicalTree(e);
+        }
+
         /// <inheritdoc/>
         void ISupportInitialize.BeginInit()
         {

src/Perspex.Controls/Primitives/TemplatedControl.cs

@@ -7,6 +7,7 @@ using System.Reactive.Linq;
 using Perspex.Controls.Templates;
 using Perspex.Data;
 using Perspex.Interactivity;
+using Perspex.LogicalTree;
 using Perspex.Media;
 using Perspex.Styling;
 using Perspex.VisualTree;
@@ -311,6 +312,17 @@ namespace Perspex.Controls.Primitives
             return this;
         }
 
+        /// <inheritdoc/>
+        protected override void OnDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
+        {
+            if (VisualChildren.Count > 0)
+            {
+                ((ILogical)VisualChildren[0]).NotifyDetachedFromLogicalTree(e);
+            }
+
+            base.OnDetachedFromLogicalTree(e);
+        }
+
         /// <summary>
         /// Called when the control's template is applied.
         /// </summary>

src/Perspex.Styling/LogicalTree/ILogical.cs

@@ -35,5 +35,15 @@ namespace Perspex.LogicalTree
         /// Gets the logical children.
         /// </summary>
         IPerspexReadOnlyList<ILogical> LogicalChildren { get; }
+
+        /// <summary>
+        /// Notifies the control that it is being detached from a rooted logical tree.
+        /// </summary>
+        /// <param name="e">The event args.</param>
+        /// <remarks>
+        /// This method will be called automatically by the framework, you should not need to call
+        /// this method yourself.
+        /// </remarks>
+        void NotifyDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e);
     }
 }

tests/Perspex.Controls.UnitTests/ControlTests.cs

@@ -212,6 +212,24 @@ namespace Perspex.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void StyleDetach_Is_Triggered_When_Control_Removed_From_Logical_Tree()
+        {
+            using (PerspexLocator.EnterScope())
+            {
+                var root = new TestRoot();
+                var child = new Border();
+
+                root.Child = child;
+
+                bool styleDetachTriggered = false;
+                ((IStyleable)child).StyleDetach.Subscribe(_ => styleDetachTriggered = true);
+                root.Child = null;
+
+                Assert.True(styleDetachTriggered);
+            }
+        }
+
         private class TestControl : Control
         {
             public new PerspexObject InheritanceParent => base.InheritanceParent;

tests/Perspex.Controls.UnitTests/Primitives/TemplatedControlTests.cs

@@ -344,6 +344,52 @@ namespace Perspex.Controls.UnitTests.Primitives
             Assert.Null(border.TemplatedParent);
         }
 
+        [Fact]
+        public void TemplateChild_AttachedToLogicalTree_Should_Be_Raised()
+        {
+            Border templateChild = new Border();
+            var root = new TestRoot
+            {
+                Child = new TestTemplatedControl
+                {
+                    Template = new FuncControlTemplate(_ => new Decorator
+                    {
+                        Child = templateChild,
+                    })
+                }
+            };
+
+            var raised = false;
+            templateChild.AttachedToLogicalTree += (s, e) => raised = true;
+
+            root.Child.ApplyTemplate();
+            Assert.True(raised);
+        }
+
+        [Fact]
+        public void TemplateChild_DetachedFromLogicalTree_Should_Be_Raised()
+        {
+            Border templateChild = new Border();
+            var root = new TestRoot
+            {
+                Child = new TestTemplatedControl
+                {
+                    Template = new FuncControlTemplate(_ => new Decorator
+                    {
+                        Child = templateChild,
+                    })
+                }
+            };
+
+            root.Child.ApplyTemplate();
+
+            var raised = false;
+            templateChild.DetachedFromLogicalTree += (s, e) => raised = true;
+
+            root.Child = null;
+            Assert.True(raised);
+        }
+
         private static IControl ScrollingContentControlTemplate(ContentControl control)
         {
             return new Border

tests/Perspex.Styling.UnitTests/SelectorTests_Child.cs

@@ -135,6 +135,11 @@ namespace Perspex.Styling.UnitTests
             {
                 throw new NotImplementedException();
             }
+
+            public void NotifyDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
+            {
+                throw new NotImplementedException();
+            }
         }
 
         public class TestLogical1 : TestLogical

tests/Perspex.Styling.UnitTests/SelectorTests_Descendent.cs

@@ -166,6 +166,11 @@ namespace Perspex.Styling.UnitTests
             {
                 throw new NotImplementedException();
             }
+
+            public void NotifyDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
+            {
+                throw new NotImplementedException();
+            }
         }
 
         public class TestLogical1 : TestLogical

tests/Perspex.Styling.UnitTests/SelectorTests_Template.cs

@@ -1,6 +1,7 @@
 // Copyright (c) The Perspex Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
+using System;
 using System.Linq;
 using System.Reactive.Linq;
 using Moq;
@@ -11,6 +12,9 @@ using System.Threading.Tasks;
 
 namespace Perspex.Styling.UnitTests
 {
+    using System.Reactive;
+    using System.Reactive.Subjects;
+    using Collections;
     using Controls = Controls.Controls;
 
     public class SelectorTests_Template
@@ -108,6 +112,28 @@ namespace Perspex.Styling.UnitTests
             Assert.False(await activator.Take(1));
         }
 
+        [Fact]
+        public void Nested_Selector_Is_Unsubscribed()
+        {
+            var target = new Mock<IVisual>();
+            var templatedControl = target.As<ITemplatedControl>();
+            var styleable = target.As<IStyleable>();
+            BuildVisualTree(target);
+
+            styleable.Setup(x => x.Classes).Returns(new Classes("foo"));
+            var border = (Border)target.Object.VisualChildren.Single();
+            var selector = new Selector().OfType(templatedControl.Object.GetType()).Class("foo").Template().OfType<Border>();
+            var activator = selector.Match(border).ObservableResult;
+            var inccDebug = (InccDebug)styleable.Object.Classes;
+
+            using (activator.Subscribe(_ => { }))
+            {
+                Assert.Equal(1, inccDebug.GetCollectionChangedSubscribers().Length);
+            }
+
+            Assert.Null(inccDebug.GetCollectionChangedSubscribers());
+        }
+
         private void BuildVisualTree<T>(Mock<T> templatedControl) where T : class, IVisual
         {
             templatedControl.Setup(x => x.VisualChildren).Returns(new Controls