Hi. I bought a gunnera plant recently at a nursery in a one gallon pot, it had already 4 leaves on it. I was advised when I bought it that it needed to be kept indoors (treated like a houseplant) until mid-april, and then planted outside. I have been faithful in caring for it, keeping it in a cool north facing window and always have kept it very well watered as I know they like boggy conditions. The problem: Over the last 3 days, although it continues to grow in height, the oldest of the leaves has gone brown and dry around the edges and this same thing is happening to a lesser degree on all the leaves. I'm scared something bad is happening to my precious plant! Any ideas? Thank you.