Plants

These plants are on shelves outside our back door, bringing them on ready to plant out when the frost's are over. 
I have a Lupin, a Primrose type plant & Hollyhocks.
The other day I went into the garden (before I hurt my back) & was so upset at the sight of our Gunnera, it was shrivelled up & brown.
I asked the advise of a friend about what had happened & she said "Possibly frost or Fox urine!".
So I've cut off the brown leaves & covered them to keep them free from frost again; I had covered them, but uncovered when they had grown some lovely leaves.