Special K: The fabulous flora of Sikkim

We returned from Sikkim (our third trip) to find the West Country once again wallowing in floods, with water pouring through the hedges either side of our route home. Finally traffic came to a standstill, with an ominous lack of anything passing by on the other side. So after a while, we did what everybody else was doing – made a wallowing turn in the water and made our way back to the main road.

Our next option proved little better. A mudslide had filled most of the Montacute road and although a bulldozer was already working on it, only one car could squeeze through at a time. After that, we prepared ourselves for the fact that the stream at the bottom of our lane would be in full spate, creating a flood too deep to drive through. So it turned out.

In bad weather in this Indian state, you get used to driving everywhere with welly boots in the back of your car. Just in case. But when we'd left home three weeks earlier, getting away had been in the forefront of my mind, not the possible problems of coming back. So there I was in my white linen holiday trousers and my Converse trainers, ill-equipped for a deep flood chasing down the lane at a dizzying rate.

My husband, frustrated by the delays we'd already had, just stripped off and waded through. But I could see that even he had problems keeping his footing. So I chose the long route, picking my way through the brambles along the top of the bank to a footbridge at the bottom of the lane. In the floods of last July, this was thoroughly submerged. This time, luckily, it wasn't, quite. Once across the flood, I had to slither through the mud, jump a few little self-made streams and work my way up the meadow towards our place. As I did, the house alarm suddenly screamed out over the valley. My husband had burst into the house, forgetting the alarm would be set and also forgetting how to turn it off. So that was our homecoming.

Compared to what was happening in other parts of the country, this was nothing. Butf compared to what goes on in Sikkim, it was even more nothing. In September 2011, they suffered a bad earthquake. In September 2012, they had an appalling late monsoon. Whole mountainsides slipped away, as we saw when we tried to pick our way into territory that was new to us, east of the capital Gangtok.

Our goal was Tsomgo Lake, sacred to the Buddhists, set at about 12,500ft, quite close to the border with Tibet. For foreigners like us, getting into border areas is never simple, but Jeetu Giri, the guide who has walked with us on all our journeys in Sikkim, had spent most of the previous day sorting out permits. The road beyond the lake (forbidden to us) leads up to the Nathu La pass, used by traders since the days of the old Silk Route.

The way then can scarcely have been any worse than it is now: 35km of chaos as work gangs and the odd bulldozer try to cut a fresh route into the raw, newly-exposed sides of the mountains leading up to the pass. And next year the work may all be undone again, the underpinning swept away by flood-swollen rivers, the walls retaining the inside edge of the road crushed by another vast fall of boulders. It puts things in proportion, travelling here.

Once again, for almost our entire stay, we had peerless views of the Himalayas. Khangchendzonga (the third-highest peak in the world) has always meant much more to me than Everest. In Sikkim, the great K is the mountain that matters, the one that ends all long views north and west, jutting forward in a spur from the main Himalayan range. To the Buddhists, it's a sacred peak and no one's allowed to climb it. At least those magnificent flanks, unlike Everest's, won't be degraded and littered with tissues and crisp packets.

Each visit we've made to Sikkim has been made later than the last. This time we were away for most of November: blue skies, brilliant sun, shining views of the mountains, stretching all the way east into Bhutan. From some of our favourite places, Martam in east Sikkim, Borong in the south, you don't see the peaks, but there are other reasons to go there.

Martam, not far from the enormous Rumtek monastery, sits in a great amphitheatre, carved into curving rice terraces that follow the contours of the slopes, all the way up to the wild forest. They were harvesting the rice when we were there, a blacksmith sitting alongside the reapers' picnic, sharpening their small saw-edged sickles (the stems are tough and the sickles blunt quickly) with his triangular file. All the work is done by hand, the rice (which looks like our oats, but with a heavier head of grain), cut and laid by one gang, bundled by another, then carried by a third to the threshing floors, dotted around all over the terraces.

The rice farmers use mud and dung to make these floors extraordinarily smooth so that when the sheaves are beaten against them, the grain falls out easily and can be swept into baskets. The straw is built up into ricks, and used for feed or thatching. You can walk out in great swoops from Martam for six or seven hours at a time and there are always things to watch and people to talk to.

Less than half a million people live in Sikkim, but you are rarely alone. There's always someone gathering fodder or firewood, harvesting cardamom, walking to school, picking guavas, laying out beans to dry. "Where are you going?" the children always ask. Walking without a fixed purpose must seem a mad idea to them.

The wild cherries (Prunus cerasoides) that grow here were in exuberant bright-pink bloom, a sight we hadn't seen before. It was named in the 1820s by the Scottish botanist David Don before the most famous of the Himalayan pioneers, Sir Joseph Hooker, ever got into Sikkim. It's not listed in The Plant Finder, which is a pity as it's far showier than Prunus autumnalis, the only autumn/winter flowering cherry that we can get hold of here.

It was also peak time for the wild purple orchid, Pleione praecox, which grows in a great swathe through the Himalayas from Uttar Pradesh to Yunnan and Szechwan in southwest China. In this country, we're most likely to see pleione on sale in a florist's shop, trapped in a cellophane box. In Sikkim, they plaster the trees of the forest, growing vertically up the trunks, horizontally along the branches, or even, having been thrown to the ground in a storm, adapting themselves to rocky banks among the ferns. They erupt, almost stemless, from whatever they are growing on (the leaves come later), so sophisticated, so elegant, so bright in their magenta clothes, it's difficult to accept that this isn't some special effect, some extravagant piece of set dressing for a movie about to be shot here in the Bollywood Hills. Incredible India. Sensational Sikkim.

The difficulty in planning a journey through Sikkim is the lack of maps. The best we've found (though still basic) is provided with 'Sikkim' by Yishey Doma (Rs499) published by Trysts and Traces in Gurgaon. Find it at Good Books, off Gangtok's main street, the MG Marg