Brunnera macrophylla is a species of flowering plant in the family Boraginaceae, native to the Caucasus. It forms clumps of softly hairy, mid green, heart-shaped leaves from which rise stems of bright forget-me-not blue flowers in the spring. The leaves then continue to provide an attractive ground cover through the summer. There used to be several variegated forms available, including one called ‘Langtrees’, which has leaves with silvery grey spots. Graham Stuart Thomas thought highly of these plants, giving the green-leaved species a star, an indication that he thought it a really good garden plant.
Recently there has been an explosion in the number of variegated forms available and members are growing them with great success. The most well-known one, Brunnera macrophylla ‘Jack Frost’, has quickly become a firm favourite and entered our Top 30 at Number 16.
But I’ve often wondered where they came from. ‘Jack Frost’ was the first, introduced by Walters Gardens Inc. in the US. It is a sport of ‘Langtrees’ and has become one of Walters Gardens’ best introductions in their 65-year history. They describe the leaves as, “intricately detailed with a crackle-like finish. Though the leaves are dark green, they have a heavily frosted overlay, which allows only the green veining to show through.” It is best grown in moderately fertile, humus-rich soil that is moist but well-drained. A cool site in partial shade or shade is preferred. It was awarded the Royal Horticultural Society’s Award of Garden Merit in 2004.
Brunnera macrophylla ‘Emerald Mist’ and ‘Looking Glass’ are sports of ‘Jack Frost’ and are also Walters Gardens introductions and it looks as though they have more in the pipeline
What is it about these plants that has made them so popular in such a short time? I imagine it’s because they are easy to grow and provide a contrast in colour, texture and shape to other plants in the shady garden – a bit of sparkle all summer.