Silver

Eryngium bourgatii - stellar

Onopordum acanthium - three thistley ghosts

My (male) neighbours at the allotment find space to grow some striking, spikey ornamentals, pictured here in mid-June.

Eryngium is a clump-forming perennial about 50cm high, so this view of its stellar bracts can be made a point of interest. If you plant it by a path, feel confident your guests will have their gardening trousers on. Hardy, so long as it's on free-draining soil. 

The Scotch thistle - a native plant and un-cultivared - being up to 3m tall, is often placed at the back of a traditional herbaceous border. Here it is displayed in all its glory, making full use of the toning mortar and contrasting brick behind it. It's a biennial that successfully self-seeds (such fun for weeding) and does well against this south-ish facing wall on unimproved soil

Herbaceous perennials in Winter

Metallic shades of ghosts of plants in the low winter sun.
Echinacea, copper in foreground
Perovskia 'Blue Spire' irridescent white like magnesium in upright bunch far left (great blue flower spikes in summer)
Eryngium giganteum 'Miss Willmott's Ghost' spiky silver to the right
Phlomis bronze button seedheads, back left
Spun gold of dried grass (battered Calamagrostis?), back right
Piet Oudolf borders at RHS Wisley.

Winter Seedheads

There is plenty of interest in the predominantly herbaceous planting around the Millennium glasshouse at the Royal Horticultural Society's grounds at Wisley, Surrey, UK.  January 2nd  was cold and clear, the sky amazing. So, with a kid's eye view I took these views of seed heads. There is not an over-abundance of plant labels, which is ok.  (l-r)

Miscanthus sinensis  'Yakushima Dwarf' (probably)

Cynara cardunculus (globe artichoke, not sure if this is a varietal form)

Eryngium (not giganteum, because too tall -c. 2m - and basal rosette still quite green and fleshy)

These herbaceous perennials give good architectural form from mid-summer on.  They remain most attractive features in mid-winter.  Can't wait to use them in planting schemes!