diff --git a/lib/nerdtree/bookmark.vim b/lib/nerdtree/bookmark.vim
index f8606ee..45f9950 100644
--- a/lib/nerdtree/bookmark.vim
+++ b/lib/nerdtree/bookmark.vim
@@ -293,23 +293,26 @@ function! s:Bookmark.str()
 endfunction
 
 " FUNCTION: Bookmark.toRoot(nerdtree) {{{1
-" Make the node for this bookmark the new tree root
+" Set the root of the given NERDTree to the node for this Bookmark. If a node
+" for this Bookmark does not exist, a new one is initialized.
 function! s:Bookmark.toRoot(nerdtree)
     if self.validate()
         try
-            let targetNode = self.getNode(a:nerdtree, 1)
+            let l:targetNode = self.getNode(a:nerdtree, 1)
+            call l:targetNode.closeChildren()
         catch /^NERDTree.BookmarkedNodeNotFoundError/
-            let targetNode = g:NERDTreeFileNode.New(s:Bookmark.BookmarkFor(self.name).path, a:nerdtree)
+            let l:targetNode = g:NERDTreeFileNode.New(s:Bookmark.BookmarkFor(self.name).path, a:nerdtree)
         endtry
-        call a:nerdtree.changeRoot(targetNode)
+        call a:nerdtree.changeRoot(l:targetNode)
     endif
 endfunction
 
 " FUNCTION: Bookmark.ToRoot(name, nerdtree) {{{1
-" Make the node for this bookmark the new tree root
+" Class method that makes the Bookmark with the given name the root of
+" specified NERDTree.
 function! s:Bookmark.ToRoot(name, nerdtree)
-    let bookmark = s:Bookmark.BookmarkFor(a:name)
-    call bookmark.toRoot(a:nerdtree)
+    let l:bookmark = s:Bookmark.BookmarkFor(a:name)
+    call l:bookmark.toRoot(a:nerdtree)
 endfunction
 
 " FUNCTION: Bookmark.validate() {{{1
diff --git a/lib/nerdtree/tree_dir_node.vim b/lib/nerdtree/tree_dir_node.vim
index 5ca94d4..4a6d213 100644
--- a/lib/nerdtree/tree_dir_node.vim
+++ b/lib/nerdtree/tree_dir_node.vim
@@ -56,12 +56,12 @@ function! s:TreeDirNode.close()
 endfunction
 
 " FUNCTION: TreeDirNode.closeChildren() {{{1
-" Closes all the child dir nodes of this node
+" Recursively close any directory nodes that are descendants of this node.
 function! s:TreeDirNode.closeChildren()
-    for i in self.children
-        if i.path.isDirectory
-            call i.close()
-            call i.closeChildren()
+    for l:child in self.children
+        if l:child.path.isDirectory
+            call l:child.close()
+            call l:child.closeChildren()
         endif
     endfor
 endfunction
@@ -220,13 +220,6 @@ function! s:TreeDirNode.getChildIndex(path)
     return -1
 endfunction
 
-" FUNCTION: TreeDirNode.getDirChildren() {{{1
-" Return a list of all child nodes from "self.children" that are of type
-" TreeDirNode.
-function! s:TreeDirNode.getDirChildren()
-    return filter(self.children, 'v:val.path.isDirectory == 1')
-endfunction
-
 " FUNCTION: TreeDirNode._glob(pattern, all) {{{1
 " Return a list of strings naming the descendants of the directory in this
 " TreeDirNode object that match the specified glob pattern.