Hadrian's Wall geology and a break from gardening

The plants are changing so little at the moment, the snowdrops two weeks behind, the aconites barely opening because of lack of sun, so I thought I would post something about a day course I went on yesterday. Run by Hadrian's Wall Heritage, it was put on to give tourism businesses some insight into the area, so we met on a dull, low cloud day but at least it wasn't raining or snowing and it was relatively warm!

Led by geologist, Richard Holmes, we spent the day in a small area around the spectacular Walltown Crags, scene of past quarrying of the hard rock of the Whin Sill and a place where Hadrian's Wall does those dramatic undulations that make it so widely photographed. Here's my own photo to add to those legions (what an appropriate word) but of course it was a very dull, uninspiring day photographically. We learnt much about the geology of this wonderful part of Northumberland, the effect of the ice sheet, the glacial erratics it left behind, the sandwiched layers of sedimentary rocks and the use that they have been put to locally over the years. But the highlights for me were often the smaller things; the tiny holes, no larger than a 5p piece, in the Whin Sill that show were gases had made their way towards its top edge - and their word, vesicles, a good one for crosswords.

Particularly fascinating was being able to see the point at which the intrusive rock of the Whin Sill met the layer of sandstone in a shallow quarry feature on the north side of the Wall. This whole area below the crags is Access Land and a great
viewpoint from which to look up at the uplifting mass of columnar dolerite. Another good detail was the current bedding - as in the photograph - which shows where the deposits that created the sandstone where moved this way and that by an ancient sea. The connection with the garden is still there in some of the plants that I spotted as we walked about, wildflowers that have herbal properties or that I grow because I like them, but it was great to have someone else do the talking and impart their knowledge for once!

Pineapple sage

The pineapple sage is in full flower in the greenhouse, unseen by visitors now that the garden is closed for winter. Its vivid red is almost fluorescent against the white back wall, its flowers on stems that reach way above my head. Its luscious flowers bloom even on Christmas Day, when every other plant in the unheated greenhouse has been cut hard back - passion flowers, asarina, campsis radicans, lemon verbena - all taken back to their main stems. Pineapple sage is not a plant for a small pot! If it is grown in a pot at all, it needs the largest size you can give it, and is happiest when growing directly in the greenhouse soil. The slightly hairy leaves have a delicate fruity scent and can be used in making puddings, the flowers used to decorate salads at a time of the year when there is not much colour. I think that is why I value it so much; an intense, dynamic red shining out in the cold winter light.

After so much rain we had a walk down by the Tyne to see the river in its height. The footpath was gone under a swirling, foaming mass of water. There was an air of danger as we watched the river speeding along, swollen and restless, making sea waves and with a furious noise. None of the usual birds were there - it was too fast for goosander, mallard, moorhen or kingfisher. Just one woodpecker announced its prescense with its single, harsh call - its always such a giveaway - a glory to watch with its flash of red against the peeling grey white of a silver birch - an echo of the red flowers on the pineapple sage.