Japanese hepaticas: pastel perfection

For me, the arrival of spring is marked by the smell of cut-grass drifting across the neighbour’s fence – a timely reminder to dust off the mower, just as the monochrome-white of the snowdrops gives way to a kaleidoscopic palette of daffodils, primroses, brunneras and much else.

Hepaticas – the flowering liverworts – are very much part of the early spring season, and are gaining a growing following of devotees here in Britain. For those yet to become acquainted with this small and delightful genus, these are diminutive anemone relatives, with distinctive three-lobed leaves (hence, apparently, the name liverwort, though quite whose liver is anyone’s guess), and simple six to eight-petalled flowers the size of smallish coins, in pastel shades of soft, baby-ribbon whites, pinks and blues. You might at this point ponder quite why a grown man is doing writing about these ineffably twee flowers, but I adore them, and have a greenhouse full of them here at Flete, the walled garden I am restoring in Devon. Indeed, as I write this, I am half way through the application process to have our collection of Japanese cultivars recognised as a National Collection by Plant Heritage.

The genus is scattered through the deciduous forest band of the temperate northern hemisphere in Europe and Asia, reappearing in North America, growing in the same lightly-cloaked, deciduous woodland in which we find primroses or wood anemones here in Britain. Some folk love the wild types of hepatica best, unadulterated by selection or hybridisation, but if you are into all-bells-and-whistles plants, the Japanese forms of Hepatica nobilis var. japonica are perhaps for you.

Back in the Edo period in Japan, 200 years or so ago, gardeners started to select and grow double and smartly coloured forms from the local woodlands, and they gained something of a cult, florists’-flower following in Japan at the time, before interests waned. Then during the 1970s, sorties into Japan’s wildwoods rediscovered hepaticas – both singles and doubles – in a diversity previously unseen. Talk, perhaps apocryphal, hinted that radiation from wartime bombing has caused the liverworts to mutate into myriad forms, many of quite exceptional beauty. From those rekindled beginnings, a Japanese obsession akin to tulip mania or our very own “white fever” centred on snowdrops has burgeoned. Today, nurseryman and enthusiasts breed countless seedlings, and thousands of the very best varieties now bear names. These are displayed at a series of early spring shows in Niigata and Tokyo, and the newest and most exotic exchange hands for the equivalent of thousands of pounds.

The variability in colour in part explains the vast array of varieties now available. Japanese hepaticas come in most colours, from white and yellow, through pinks and near reds, to blues, purples and near blacks. Persimmon and wine coloured forms, the colour of cooked trout and Cadbury’s chocolate wrapper-purple respectively, are particularly sought after, as are some of the clearest cobalt blues, rich buttery yellows, and greens. Some coloured flowers have brilliant white stars or bands in their centres, whilst pale pinks and whites occasionally boast richly coloured picotee margins or a fine tracery of veins.

However, it is in their flower form that they reach utter perfection. The variety is mind-boggling, and can only occur because the central boss of carpels, encircled by the stamens, have become petaloid or foliose to varying degrees. The International Hepatica Society recognises nine distinctive flower forms. Perhaps best loved are the senne or senju varieties, typically full and perfect doubles – their name literally means thousand-layered - while in others the centre of the flower is filled with green, seemingly foliose petals (so-called sandan-zaki types). Yet others - the nidan-zaki types, just the anthers have become petaloid, and are often spatula-shaped – like the card matches in complimentary hotel match-books, according to bulb grower and nurseryman Paul Christian.

Like some forbidden fruit, news of these fantastic forms has dribbled out to plant enthusiasts in the west over the past decades, but only in the last 20 years have named varieties reached the European mainland and British shores. Today, across Europe perhaps as many as 1,000 cultivars are being grown and propagated, and they are increasingly becoming available through a few specialist nurseries. Indeed, as the price of snowdrops soar, the price of these Japanese beauties is gently dropping, making them ever more available to wider audiences.

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Whatever you read to the contrary, hepaticas are actually perfectly easy to grow, provided that a few simple rules are followed. In Japan, they are known as yukiwariso - literally the flower that breaks through the snow, doing most of their growth in spring before the trees leaf up, so it pays to keep them reasonably dry in winter and summer, but wet in spring and autumn when most root growth takes place. They can survive a good deal of light in early spring, but like to be shaded from late March onwards. At Flete, we grow ours in deep 1 or 1.5 litre pots, in a mixture of equal parts coir, medium potting bark, John Innes compost and coarse perlite, with slow-release fertiliser added – it should drain instantly when watered, and they seem to thrive on this diet. Conversely, they abhor claggy, sodden compost that has lost its airy structure, so aim to repot every other year, at roughly the March or September equinoxes, at which time they can be divided providing material for swapping or giving to friends.

A final thought. Until now they have been too rare or too expensive to try out of doors, but I have heard of growers succeeding with them in shady garden spots as far apart as southern England and Eastern Scotland. So let’s hope that as prices fall and they become increasingly available, more enthusiasts will try them in the open garden. If you are interested in trying your hand at these miniature gems, then Edrom Nurseries and Ashwood Nurseries are good sources of these plants at the present moment. As for recommended varieties to choose: I would merely decide your budget and buy whatever takes your fancy, for there really is no such thing as a ugly hepatica. But beware, you will most probably become addicted.