Athyrium filix-femina · Fern
Drought stress: Deep weekly soaking in dry spells and a 5-8 cm mulch of leaf mould or bark to keep roots cool and moist.
Vine weevil: Check compost around the crown in autumn for small white grubs; treat with nematode biological control if present.
Late frost damage: Throw a couple of layers of horticultural fleece over the crown overnight when a hard frost is forecast after frond emergence.