Common Rockrose - Helianthemum nummularium

We are so lucky that a few hundred metres further up the stream that runs past our new house is a lovely bit of valley that used to be grazed by sheep. About 15 years ago it changed hands and the new owner has planted scattered trees and doesn’t have any livestock grazing the area.

This section of valley has a great variety of wild flowers growing. These include Heather, Tormintal, Thyme and Rockrose on the slopes, with Meadowsweet, Knapweed and various other flowers in the damper areas.

It is also a fantastic area for butterflies with Dark Green Fritillaries, Small Pearl-bordered Fritillaries, Meadow Brown, Ringlet, Common Blues and Northern Brown Argus all being recorded in good numbers.

The Northern Brown Argus, Aricia artaxerxes, uses Common Rockrose as the food plant for its caterpillars.

Four years ago when I was walking there, I thought to myself that I was following the same stream that runs through our property further down the valley and therefore the conditions with us should also be good for Rockrose. Much of our land was unmanaged woodland when my father bought it 20 years ago. However, we have done a lot of work to open up the woodland, particularly close to the house, and I wondered if it would be possible to re-establish Rockrose there.

So, having received advice from a colleague at work, I took some hardwood cuttings in May of 2016. I was advised to fill a seed tray with gritty compost, covered with a centimetre of sharp sand. Strip off the lower leaves from a woody shoot of Rockrose, about 6 centimetres long and push it through the sand into the compost. Once the tray was full I gave it a good water and let it drain before putting it inside a large polythene sack and sealing it up. This was left in an unheated conservatory and a couple of months later I noticed that many of the cuttings had grown and some were flowering!

Later that year I potted the cuttings into individual 6cm pots. This highlighted a bit of an issue, as each cutting had produced one or two very long roots and they were all rather entangled. So, by separating them out I broke a few roots. However, I ended up with 16 plants in pots, which I kept in a sheltered location for the winter. I let them grow on the following summer and planted them into my chosen site in the autumn of 2017.

I ended up with ten good plants, which didn’t grow very much during 2018. In 2019 I bought some plugs of Thyme and wild Marjoram, which I planted between the Rockrose. I had noticed that there is a lot of Thyme growing in the valley, which the Northern Brown Argus were often seen feeding on.

I am very pleased with the way my little patch of Rockrose is developing. It hasn't all gone perfectly. When I added the Thyme, I also put a couple of plugs of Vipers Bugloss plants in. These grew much larger than I expected and ended up almost smothering some of the Rockrose.

I tried planting some more cuttings this summer, but they all failed. I think I was just a little bit too late in the season for them to work.

The biggest thrill this summer was spotting a Northern Brown Argus just next to our house. They are not meant to fly far from their colony, but this one must have been at least 500 metres from the closest colony. Although I didn't see it again, it proves that these little butterflies do explore and maybe in the future, once my Rockrose is more established, they may find it and form a new colony here.