How not to make your garden wildlife friendly
A report published this week from Plantlife has found that alien plant species are a big threat to our native wildlife. They cost more than £1.7 billion a year to clear up and affect some of our most beautiful landscapes, including the Lake District.
Weed it out: The water primose is one of the worst offenders (photo copyright: Trevor Renals)
What's this got to do with our gardens? We've all heard of the problems caused by Japanese knotweed. No one's going to willingly plant that in their garden any more. (Scary thought: you can be refused a mortgage if your neighbour has it in their garden.)
But you can still buy some of the worst, most invasive offenders from your local garden centre. They have the potential - if they escape from gardens or ponds - to be so harmful to our biodiversity that Plantlife is calling for them to be banned.
Some of these danger plants are even sold under a 'Buy British' slogan. Don't be fooled - they've been cultivated in Britain but are as far from native as it's possible to be. And watch out for plants which are sold as 'oxygenating' plants for ponds and aquaria. Some of these bad boys can actually lead to great fluctuations in oxygen levels which are harmful to your fish and invertebrates.
All the good work you do for wildlife in your garden could be undone by planting these rascals in between your dahlias and pansies, or in your pond. So however pretty, useful or interesting they may look on those garden centre shelves, just walk on by.
The rogues' gallery (in no particular order):
Large-flowered waterweed Egeria densa (photo copyright: Dominic Price, Plantlife)
Curly waterweed Lagarosiphon major (photo copyright: Su Cooper, Plantlife)
Pirri-pirri-bur Acaena novae-zelandiae (photo: Crown copyright)
Parrots-feather Myriophyllum aquaticum (photo copyright: Tim Pankhurst, Plantlife)
New Zealand Pygmyweed Crassula helmsii (photo copyright: Deborah Long, Plantlife
Hottentot fig Carpobrotus edulis (photo copyright: Sue Nottingham, Plantlife)
Some more offenders:
Water primrose Ludwigia grandiflora (pictured above)
Early eradication of this blighter would cost an estimated £73,000. If it's allowed to establish as it has in France it might well cost £242 million.
Three-cornered garlic Allium triquetrum
Few-flowered leek Allium paradoxum
Caulerpa racemosa, a marine algae/seaweed that people buy for their aquaria
It's not like we're facing a real-life Day of the Triffids (Plantlife are keen to stress that only a small number of the 70,000 or so non-native plants available to buy in Britain actually pose a risk), but it's worth making sure, despite your best intentions, that you're not doing more harm than good. After all, more than 60% of invasive plants in the UK are garden escapees.
I'd urge any keen gardener to have a look at Plantlife's advice about invasive species. The golden rules are especially good:
NEVER release ANY garden or aquarium plants into the wild
- Don't tip them down land drains
- Don't dump them in the countryside
- Don't throw them into your normal waste bin
- Do compost or burn them or use your local council garden waste collection
(The BBC Gardening Blog has a great post about the dangers of pond invaders.)
Update 7 March 2011: Plantlife is hopeful that there will be movement on bans of sale later this year. We'll keep you posted.