Graham Porter’s gardening column: plant of the week: corydalis flexuosa

May 16 2009 by Linzi Nicholson, Huddersfield Daily Examiner

THIS rather unlikely member of the poppy family has a flower colour that is seldom seen in other garden plants.

It is amongst the purest blues, surpassed perhaps only by Gentians and it continues to flower for up to two months from April through to June, with the flowers spikes hovering over purple tinted fern-like foliage.

Its growth is very delicate and brittle so it is best to grow it in a sheltered part of the garden, preferably with partial shade – this helps it to retain its flowers for a longer period, giving you more value for money.

By late June the top growth will have died off and it is best to mark the place with a cane to stop you from hitting the dormant crown with a fork or a hoe.

To increase your stock of the plant, or to give some of it away to friends and neighbours, well-established clumps are best lifted and divided in early October, overwintering smaller pieces in pots in a cold frame.

There are several other worthy species to look out for, including Corydalis lutea, which is a British native, often seen growing out of dry stone walls in the South West of England and Corydalis ochroleuca with white flowers in late spring and summer – this may, in the right soils, self-seed so be warned.