THISTLES are some of the most pernicious and obnoxious weeds ever invented. The standard farmer’s nightmare version spreads far and wide via tough underground roving roots, and sends forth clouds of airborne seeds to colonise pastures new. Its fiercely prickly nature ensures grazing animals won’t touch it, and its ambitions for world domination have seen laws passed against it. Approaching them in anything less than stout boots, thornproof clothing and leather gloves is not to be recommended.

There are thankfully a few garden-worthy species of thistle, however, and a particular beauty can be found in borders right now. Cirsium rivulare Atropurpureum is its official latin name, and although quite a mouthful, it is worth getting it right as this is a plant any border would benefit from. It has all the best thistle-like features without any of the downsides.

The mounds of soft green, jagged foliage although appearing a little dangerous at first, are in fact only softly prickly and will do little more than tickle the ungloved hand. It also has none of the spreading, evil empire building aspirations of its relatives. This gentle plant slowly builds a clump without straying from where it is placed. Even its ample feathery seed heads when split and blown upon the wind give rise to no new colonies. In the garden it certainly gets top marks for good behaviour.

It is its flowers though that earn this thistle a place in the border. Strong, leafless stems rise up to a height of about four-feet and are topped off with neat groups of deep magenta red flowers. Their bristling, tightly trimmed forms make perfect landing pads for bees and butterflies which seem magnetically drawn to their charms.

The ‘see through’ and statuesque nature of the flower stems mean that this is a plant that can be usefully deployed at the front of the border, as well as further back. It also flowers on and on from an early summer start, particularly if dead-headed early in the season. Later flowers can be left to develop fine seed-heads to entertain the goldfinches.

With most thistles, their presence in the garden can only lead to regret and resentment, but given rich, moist soil and a sunny position, this one, Cirsium rivulare ‘Atropurpureum,’ can be richly rewarding.

Chris Crowder is head gardener at Levens Hall

Jobs to do this week:

Sow biennials for flowering next spring and summer such as forget-me-nots, sweet williams and wallflowers. Move them into their final positions in the autumn.

Cut back and tidy away the dead foliage of early bulbs.

Regularly tie in new growth of climbing plants.