Tack! Där stod det väldigt tydligt hur jag ska göra!
För intresserade som inte orkar läsa hela PDFen:
"Established plants can be divided in
early spring. Alternatively, 15–20cmlong
sections of rhizome from robust
plants can be dug out and replanted
in spring to early summer. These
should be planted 3cm deep in a
rich, organic, free-draining soil at
pH 5.5–7 with a small amount of
fertilizer. The soil should be kept
semi-moist, but never waterlogged.
Plants benefit from a mulch, and this
will aid emergence of the flower
buds, especially if one intends to
use them for culinary purposes. "