The child is presented using emotive language, reflective of the compassion and sympathy the speaker feels for his injured son: "White blisters beaded on his tender skin". The alliteration using the 'b' sounds suggests the swelling, painful injuries, and the child's skin is "tender", a strong contrast to the language used to describe the nettles. The "watery grin" is another emotive description, implying the child is being helped to get over his painful experience by loving parents.
The father's reaction to the nettles is as violent as the nettles' stings. He explains the process of dealing with the nettles in a very careful, calculating manner: "I took my hook and honed the blade". First he selected his weapon (a scythe), then sharpened it; then he "slashed in fury" until "not a nettle ... / Stood upright any more". The father takes revenge in his strong desire