Visitors to The Alnwick Garden’s Poison Garden, which I love to take tours around in season, are forever asking as we walk through the dark, ivy-clad tunnels: ‘Is this poison ivy?’
‘No,’ is the immediate response, ‘it’s ivy which is poisonous.’
A brief explanation follows. ‘The so-called poison ivy (toxicodendron radicans) is a plant indigenous to North America. It trails and climbs like our native ivy and there can be a highly allergic reaction when it is in contact with human skin.
‘This is our native ivy hedera helix Hibernica or common ivy, which should not be underestimated.’
As in the case of holly and mistletoe, birds can feast on the fruits without harm but should we ingest any, the saponins they contain may trigger an adverse reaction.
This can include a respiratory problem and convulsions. Milder effects from contact with the leaves include a fit of sneezing and skin or eye irritation. This is why it’s wise to wear a mask, gloves and eye-shield when trimming or removing the plant from a wall.
Despite these potential contact problems we still weave a few ivy strands into our Christmas arrangements, mindful of its historic significance in our celebrations.