So, what are your plans for the weekend? How about going to visit a garden?

It might not be your first thought in the depths of February, when cups of tea and roaring fires are the alternative. But around 90 doughty gardeners each year are brave enough to let other people see their gardens in winter for the National Gardens Scheme, and hundreds of visitors turn out: if you opt for a cuppa instead, you're missing some real winter highlights.

Dr Margaret Lloyd and her Mahonia x media 'Charity'

Opening your garden to the public in the ‘off’ season is not for the faint-hearted. Every plant must earn its place: and the weather is at its most fickle. Dr Margaret Lloyd is an NGS veteran, and after 16 years opening her one-acre garden, Little Cumbre in the outskirts of Exeter in Devon, she takes such challenges in her stride.

“We’d visited a few gardens and thought, let’s see whether people would want to come to us. So it came out of a wish to share it with people.”

Opening your garden in summer is brave enough, but in winter it's positively heroic. When I visited, days before she welcomed her first winter visitors, badgers had been digging up her lawn and many of her 34 different types of snowdrop were still stubbornly slumbering after weeks of Arctic temperatures.

“The weather is an anxiety at any time of year when you open. Two or three years ago I was praying for some cold weather to hold things back!”

Some people would be out there with hairdryers trying to wake their snowdrops up - don’t laugh, it’s happened - but it’s a sign of the strength of planning behind this garden that such setbacks don’t matter a jot.

Mahonia x media 'Charity'

Never mind the snowdrops: just look at the stately Mahonia x media ‘Charity’, with its firework bursts of yellow flower, and just smell that Christmas box! There are hundreds of hellebores in shades of sultry plum purple, and ‘Jacqueline Postill’ - one of the best daphnes - scenting the bits the Christmas box doesn’t reach: “I think it’s such a bonus to have the perfume as well” comments Margaret.

And you suddenly notice that trees have bark. Silver birch glows dazzling white, cinnamon-coloured wafers of the paperbark maple, Acer griseum, curl into tatters, and a lovely Prunus serrula shines copper in the front garden. Climb the hill behind the house, and you’re in a wilder, wooded area where majestic holm oaks and a fine Luccombe oak tower over grass spangled with Cyclamen coum and crocus. This is planting to remind you that even in winter a garden can be a wonderful place to be.

But what everyone comes to see - more than 100 on a good day last year - is the collection of snowdrops. At 34 varieties, it’s not the largest: but each one is chosen with care, and Margaret isn’t one to obsess.

“I don’t hunt them down in the way that a true galanthophile will. And I have no wish to increase my numbers of varieties now because I haven’t got enough space for them - it’s full!”

And I couldn’t see where the cold weather delays had made so much as a dent in the display. The ground is peppered white with snowdrops: early flowering stalwart Galanthus ‘S Arnott’, G. atkinsii nestling fetchingly against some steely-blue emerging dianthus foliage; and exquisite yellow G. sandersii nudging a butterscotch head above ground.

“People love the early start to the year: snowdrops are the first real sign that spring is on the way, It’s the beginning of the outdoor season - it’s just lovely.”

Little Cumbre, Exeter, Devon opens on Sundays 6, 13 and 20 February: adult admissions are £3.50, children free. Visitors are also welcome at other times by appointment.