HE’S banged the drum for the Gurkhas, been an ambassador for combating climate change and waste and now, actress and keen gardener Joanna Lumley has turned her attentions to the plight of the humble butterfly.

The star is backing this year’s Big Butterfly Count, the world’s biggest survey of butterflies organised by Butterfly Conservation and Marks & Spencer.

“I’ve been fascinated by butterflies ever since being brought up in the Far East she explains.

“The great heartbreak is to see how few there are today.”

The public is being asked to take 15 minutes to participate in the count, which runs from July 20 to August 11 (prime time for butterfly activity), to help identify trends in species that will aid us in planning how to protect butterflies from extinction, as well as understanding the effect of climate change on wildlife.

Butterflies react very quickly to change in their environment which makes them excellent biodiversity indicators. Butterfly declines are an early warning for other wildlife losses.

Almost three-quarters of UK butterfly species have decreased in population during the past decade, while the number of UK’s larger moths has crashed in the past 40 years, according to recent reports by a group of leading conservation organisations.

The predictions are that numbers will be down again this year,” says Butterfly Conservation surveys manager Richard Fox.

Lumley’s own London garden, with its wild area of meadow planting at the end, should be a haven for butterflies, but she has seen few this year.

“That’s quite a good area for butterflies, but I’ve maybe seen three this year,” she explains.

“Like the bees, suddenly there’s been something catastrophic happening. Something we are doing is wrong.

“I suspect we have to blame it on our methods of farming, but I think it’s also down to our way of living in our urban environment, getting rid of gardens and putting down decking, paving stones and tarmac, treating our vehicles as more important than our creatures.”

Lumley has planted many butterfly-friendly species in her garden.

“I love nettles, as do butterflies. It's important not to be too tidy in your garden, because butterflies love species that aren't necessarily the smartest flowers.

“I have Michaelmas daisies, buddleia, lavender, honesty, dandelions. Butterflies like all of these.”

TOP TIPS Here’s some tips to attract butterflies to your garden: n Choose sunny, sheltered spots when planting nectar plants, because butterflies like warmth.

n Select different plants to attract a wide variety of species.

n Prolong flowering by deadheading regularly and watering well.

n Don't use insecticides and pesticides which kill butterflies and many pollinating insects.

n Grow plants which will attract butterflies including buddleia, Verbena bonariensis, lavender, perennial wallflower, marjoram, phlox, nasturtium, escallonia, cone flower, aster, sweet rocket, lobelia and herbs including chives, thyme and mint.

For more details on the Big Butterfly Count, go to www.bigbutterflycount.org