When creating the new garden in 2014, following the advice of Fanny from the Esat La Simonière nursery, I planted a specimen of Lavatera ‘Barnsley’, more exactly Lavatera x clementii ‘Barnsley’. This variety of lavatera is in fact what is called a ‘periclinal chimera’, a not quite stable mutation of the cultivar Lavatera × clementii ‘Rosea’, also known as Hyères Lavatera (syn. Lavatera olbia ‘Rosea’).
Lavatera x clementii ‘Barnsley’ 19/07/2015 
Lavatera × clementii ‘Rosea’
I was aware of this peculiarity, as well as of the short life span of lavatera in general, but I had not experienced any reversion to type during the first 4 years of the existence of this plant in the garden. On the other hand I had already noticed the loss of my first specimen after only two seasons. Luckily I had taken the precaution of making some cuttings (which “set” easily) and the present specimen is the result of one of those cuttings. For more details on the evolution of this plant in the garden, see its file.
It is only last year, in 2019, that the reversion began to appear, on a layering made at the foot of the well developed specimen. In this photo you can clearly see the ‘Barnsley’ type flowers on the left and the reversion to the ‘Rosea’ type on the right.
I followed the advice to remove as soon as possible the few stems affected by the reversion, but nothing changed. This year, in 2020, the problem concerns almost half of the flowers. In addition, a few ‘Barnsley’ type flowers have a dark pink streak on one or more petals indicating the tendency to revert to the type (picture on the right).
So what now? This season, the mixture of the two types of flowers on the same plant gives a rather pleasing result. But I am not interested in a plant that is entirely of the ‘Rosea’ type, whose darker pink I find more common and less graceful than the lighter pink ‘Barnsley’ type. I will try some cuttings, taking stems that have remained true to type, but there is no guarantee of results. I could also buy a real ‘Barnsley’ from a garden centre, but… again without any guarantee. Indeed, in my local garden centre I was recently surprised to find that a lavatera labelled ‘Barnsley’ had dark pink flowers, so it had already returned to the ‘Rosea’ type even before it was sold!
Note – For more information on the reversion to the type of this lavatera see this well-documented page on The Garden of Paghat the Ratgirl website.