C# Razor beginform binding nested object in view and post it all back to controller

I have a view model like this:

namespace MySystem.Models.View {
   public class ItemPage {
      public Item Item { get; set; }
      public int CurrentItemID { get; set; }
      public string ModalHeading { get; set; }
      public string SubmitButtonText { get; set; }
      /// <summary>
      /// This will be the color that we will use in the view, if set
      /// </summary>
      public System.Drawing.Color CssColorTwist { get; set; }
      public ItemPage() {
         //ItemEngine iEngine = new ItemEngine();
         //this.Item = iEngine.GetItem(CurrentItemID);
      }
      public ItemPage(Item item) {
         this.Item = item;
         this.CurrentItemID = Item.ItemID;
      }
      public ItemPage(Item item, string btnText, string modalHeading) {
         this.Item = item;
         ModalHeading = modalHeading;
         SubmitButtonText = btnText;
         this.CurrentItemID = Item.ItemID;
      }
      public ItemPage(Item item, string btnText, string modalHeading, System.Drawing.Color cssColor) {
         this.Item = item;
         ModalHeading = modalHeading;
         SubmitButtonText = btnText;
         CssColorTwist = cssColor;
         this.CurrentItemID = Item.ItemID;
      }
      public Color GetCssColorDarker(double factor) {
         if(CssColorTwist != null) {
            return CssColorTwist.GetColorDarker(factor);
         }
         return new Color();         
      }
      public Color GetCssColorLighter(double factor) {         
         if (CssColorTwist != null) {
            return CssColorTwist.GetColorLighter(factor);
         }
         return new Color();
      }
   }
}

I want to bind and set the nested item properties in the view like this:

<span class="display-form-item">@Html.DisplayNameFor(model => model.Item.Address):</span>
@Html.TextBoxFor(model => model.Item.Address, new { @id = "addressID-" + @Model.Item.ItemID, @class = "form-control", data_toggle = "tooltip", data_placement = "bottom", @title = "Skriv inn adresse" })
@Html.ValidationMessageFor(model => model.Item.Address, String.Empty, new { @class = "alert-danger" })

When posting to the controller, all the properties of the view model end up as null. If I remove the nested object Item from the view model and remove all bindings to that nested object in the view, then all works good, all other properties are set.

So the problem is, how to bind nested object properties in the Item object in the view and post back to the controller with the model and nested object and all?