Since the beginning of the month great bunches of mistletoe (Viscum album) have been on sale in green grocers throughout the country and here - close to the Museum in South Kensington - is no exception.
James McKay presents one of his mistletoe bunches from his shop in South Kensington
In common with many others, I’ve always been fascinated by this curious plant and was pleased to find it growing on lime trees across the fields from where I once lived in Kent. Until then I had only seen mistletoe growing in northern France - again, probably on lime trees.
Mistletoe (the 'globes' of green among the branches) growing on Lime. Image: Jonathan Briggs
Mistletoe is an evergreen, semi-parasitic plant absorbing water and nutrients from host trees. It is spread by several bird species, including of course the mistle thrush. Mistle thrushes swallow the whole berry and the sticky seeds pass through their gut. The excreted seeds, retaining their stickiness, fall and often stick to branches of the host tree where the seeds may germinate.
Mistle thrush. Image: jsutcliffe/Flickr
Creative Commons licence BY-NC-SA 2.0
Blackcaps are also rather partial to mistletoe but first separate the seed from the white flesh, leaving the viscous seed on the host branch, before eating the fruit. Mistletoe has a particular affinity for apple, lime, hawthorn and
poplar in relatively open habitats, such as in orchards, parks and gardens.
Male blackcap. Image: Edwyn Anderton/Flickr
Creative Commons licence BY-NC-SA 2.0
Apart from the local green grocer, there is no nearby source of these white berries for birds to spread. My own attempts at propagating mistletoe seeds on our apple trees in the Wildlife Garden failed - so when Jonathan Briggs of Mistletoe Matters offered to introduce mistletoe to some of our trees, we welcomed the suggestion.
Jonathan planted seeds on branches of two apple trees, an old ornamental hawthorn and willow in April 2009. The seeds successfully germinated on several trees and managed to survive on the apple and willow.
Jonathan Briggs explains his reasons for introducing mistletoe to the garden:
“The mistletoe planting in the Museum’s Wildlife garden was part of a programme of mistletoe plantings in selected London locations linked to the original Greater London Biodiversity Action Plan. Mistletoe was included in that on the basis of its rarity (in the London area), ease of monitoring and cultural significance.
“Other planting sites included Kew, Chelsea Physic Garden, Buckingham Palace Garden and Down House (Darwin's place - he admired mistletoe's adaptations). Key existing populations in the London area are largely around Hampton Court where it has been recorded for over 200 years on the famous limes, and in the opposite corner of London in Enfield where there is much in the Middleton House/Forty Hall area.
“Since the London project there has been increasing evidence that mistletoe may be becoming more common anyway in eastern counties - perhaps due to climate change, perhaps due to increased spread from more over-wintering blackcaps or perhaps a combination of both. Spread from tree to tree is increasing around Hampton Court and in Essex.
“At the same time, over in the SW Midlands which are better suited to mistletoe climatically, there is continuing loss, in biomass terms, of mistletoe in old apple orchards - which are in decline. These orchards are one of its favourite habitats, so the loss of the orchards inevitably leads to less mistletoe. It does not, however, mean mistletoe is threatened - it is still thriving in other habitats, so it is only quantity that is reducing.
“Actually, in some orchards, mistletoe quantity is increasing, as the trees have become unmanaged and the mistletoe allowed to overgrow them. This is only temporary however as the trees involved are mostly old, and the overgrowth of mistletoe will accelerate their death - so this 'glut' in some orchards will be gone in a few years. A survey, the 'Mistletoe League' is collecting information on attitudes to mistletoe management in fruit trees (in both orchards and gardens) - do take part if you have mistletoe on fruit trees, all information is useful.
“If you want to try growing your own there are detailed instructions on the Mistletoe Pages website. Mistletoe is a parasite and will affect the branch it is growing on - but it won't harm the whole tree unless allowed to take over. Some pruning every winter will prevent that happening!”
... it will be sometime before our delicate mistletoe threatens its host trees:
A healthy young plant on apple (Malus domestica) ‘Brownlees Russet’ in the Museum’s Wildlife Garden. Image: Jonathan Jackson
These fresh green and healthy-looking plants appear new and shiny on the otherwise bare and wintry branches and perhaps this is why mistletoe was thought to symbolise new life at the winter solstice - just one of many beliefs associated with this enigmatic plant.