WARNING: The above gallery contains images of Harrison's injuries that readers may find distressing.

A MUM is warning parents to be wary of giant hogweed after her 12-year-old son’s leg became covered in blisters when he came into contact with the plant.

Sarah Byrne’s son Harrison Broadley was left with huge blisters on his knee after coming into contact with giant hogweed when playing on a trampoline in the family’s back garden on Mill Lane in Lymm.

The poisonous plant can cause severe injuries, and has been growing in a field at the rear of the house.

Mum Sarah said: “We’d heard of giant hogweed but we didn’t really know what it was to be honest, and it wasn’t until we went to the hospital that we realised.

“It started with a little blister which was kind of itchy and then through the night it just got worse and worse.

“The blisters covered the whole of his knee and went halfway up his leg.

“Harrison has still got a big scar on his knee but it took about a week-and-a-half to go down with antibiotics.

“He’s 12 but if it had happened to a younger kid it could have been a lot worse.

Lymm High School pupil Harrison’s blisters were worsened as the effects become more severe if exposed to sunlight.

Sarah has so far been unable to track down who the land where the giant hogweed has been growing belongs to, and fears the plant will return to her garden if no action is taken.

She added: “At the back of where we live there is giant hogweed growing, and obviously it’s blown into the bottom end of our garden and grown there.

“We’ve had someone in to treat it after this happened but it will carry on coming in because we can’t control what’s at the back of us.

“It’s just spreading and spreading and it’s just a matter of time before a smaller child gets affected by it.”

Both Warrington Borough Council and the Environment Agency told the Warrington Guardian that the land did not belong to them.

An Environment Agency spokesman said anyone responsible for encouraging invasive non-native plants to grow in the wild could be fined or jailed.