Made the form require login and look slightly prettier.

app/views/gardens/edit.html.haml

@@ -1,9 +1,11 @@
 = content_for :title, "Edit garden"
 
 - if user_signed_in?
-  = form_for @garden do |f|
-    = label_tag :name, "Name"
-    = f.text_field :name
-    = f.submit "Save"
+  = form_for @garden, :html => {:class => "form-horizontal"} do |f|
+    .control-group
+      = f.label :name, :class => "control-label"
+      .controls= f.text_field :name
+      .form-actions
+        = f.submit "Save", :class => 'btn'
 - else
   .alert You're not logged in. Only logged in users can do this.