I think the stuff from Dawnguard cannot be applied to the new houses. For instance, in the trophy room you can't have Forgotten Vale animals.
Crimson Nirnroot isn't from Dawnguard, it's found in only in Blackreach. It supposedly will only grow there, which is likely why you can't put it in the greenhouse.
Crimson Nirnroot isn't from Dawnguard, it's found in only in Blackreach. It supposedly will only grow there, which is likely why you can't put it in the greenhouse.
You're right, don't know what I had in mind (maybe the thing that grows in the Soul Cairn). My bad.
I find it weird that I can't plant Yellow Mountain Flowers, but I can plant the other colours...
Ingredients not in the base game were probably ruled out. No doubt a compatibility issue for people who might have the hearthfire addon but not the others.