The genus Celmisia is exclusively Australasian, with a handful of species found in the mountains of S.E. Australia and Tasmania.The rest, sixty or so species, are endemic to New Zealand. Whilst all the species have white daisy flowers there is probably no other alpine or sub-alpine genus with such variation in form and foliage. At one end of the spectrum are the large silver leafed and golden leafed forms of Celmisia semi-cordata and C. semi-cordata ssp. aurigans; at the other end the tight silvery and gunmetal cushions of C. sessiliflora and C. argentea. Between the extremes are a host of mat forming and sub-shrubby species; all with interesting foliage and making a substantial contribution to the winter garden.
Celmisia allanii forms a low, spreading sub-shrubby mat. The leaves are soft and furry, light grey on the upper surface and pure white on the lower and vary from 3 – 6 cms long x 1 – 1.5 cms wide. The 3cm white daisy flowers are full petalled on stalks 15cm long, making for a nicely proportioned display. C. allanii grows relatively quickly in the open ground and in five years will produce a 70 to 90cm mat with over 1,000 flowers when well suited.The species is easy to propagate. Simply remove a 7 to 8cm terminal shoot, clean back the lower leaves to leave 5cms of clean stem and dibble the cutting into an uncovered, shaded sand plunge. Cuttings so treated in early May will be well rooted by the end of September. My own National Collection of celmisias is largely planted out on an open north facing slope and in a deep, gritty loam derived from old grass pasture. Into that naturally well drained soil I have dug leaf mould and composted bark to provide some moisture retention although mature plants will send their root system well beyond the humusy upper layer, often to depths of 1 metre. They also seem to enjoy full wind exposure and the cooler summers experienced in the northern half of Great Britain. Hot ,dry summers, coupled with warm night time temperatures are not enjoyed by celmisias. In such situations adding large amounts of water simply encourages rot in the crown of the plant.
That said, Celmisia allanii is one of the species more tolerant of a wider range of climatic conditions (it occurs in New Zealand in the rain shadow areas of Nelson and N.W. Canterbury) and grows well for me all around my garden, including an open, gently sloping, south facing terrace where it has happily self sown.The photograph is of a plant on that terrace. For those wanting to grow a celmisia this is the one to try.