Sadly, you can complete only one of these areas each day, either Wardens or Druids. Once enough marks are accumulated you can open up first one area and then (at a faster rate with the extra dailies) the second area.
It is more or less personal preference which one you choose to open up first though one set of the Shadow Council dailies (starting with Mysterious Seed and leading to the Crimson Lasher) can be done in the Ashen Fields. The starting quests for these new areas are available from Malfurion Stormrage (in the cave at Malfurion’s Breach), each costing 150 Marks of The World Tree to complete. The next step, once the portal to the Molten Front has been opened and access to the dailies at Regrowth area and at Malfurion’s Breachhas been gained, is to enrol the aid of Druids of Talon & the Shadow Council thus opening up two new areas ( the Furnace and Forlorn Spire), quests, dailies and achievements.
