In the first ever botanical week, the seven remaining cooks face three tasks inspired by nature as the competition to become Britain's best amateur baker continues. The competitors start with a signature challenge that requires citrus flavours and perfect peaks, before tackling a leafy technical. Finally, they must create three tiers of elaborately decorated cake for the showstopper, before judges Mary Berry and Paul Hollywood cast a critical eye over their efforts. Presented by Mel Giedroyc and Sue Perkins