No it's easy, they make small crowns on the surface and spread about but are shallow rooted. I started with a small pot, then split the crowns into several pots and they grew well. That was years ago, I had made a raised hosta bed under a tree canopy and filled it with those plants. The foliage grows over winter and flowers in spring, it flowered for ages but when the hostas grew over them the Corydalis plants started to rot. It was a spectacular sight when the bed was full of them! I've had the plant for probably 13 years now, if I could find a space for them to grow the same I would but my garden is full.