A Northumberland Alpine Gardener's Diary
This entry: 25 October 2008 by John Richards
Northumberland Diary. Entry 95.
We have been away for a week. I gave two lectures, firstly at Ness to the RHS rhododendron group that meets there, and then to the Somerset Group of the AGS, which meets at Taunton. In between we spent a few days in the south-west, staying at Dunster, and in between showers we were able to enjoy autumn colour at Stourhead, Dunster, Knightshayes and Killerton. I am trying to build up a library of images of autumn colour, and I was able to add over 100 pictures to this. Knightshayes was particularly good. However, I fear that the gales that are blowing as I write today may have spoilt many beautiful vistas since then.
I may find room to show a few of these next week. However, at present there is plenty of material in my own garden. Before we went away, I took advantage of three clear days with a reasonable forecast to undertake a second major project of the autumn (one of the D beds was renewed in late August).
When we were developing the garden, one of the last areas to succumb to the turfing tool, about nine years ago, was made into a scree. Once the turf was lifted, a plastic liner was put down and about 15 cm of rotted compost put on top. Four two ton jiffy bags were delivered, one with coarse sand, and the other three each with a different grade of river gravel. These were added successively, the coarsest at the the bottom, and the sand last, on top. No further compost of any kind was added.
The scree lies to the north of the house, and slopes northwards, so it is a cool site which receives no direct sunlight in winter. However, at mid-summer it can be sunlit for 12 hours. It is about 6 m square, covering perhaps 28 sq m. On the whole, it has not been a successful home for difficult plants, perhaps because it rapidly became dominated by two prostrate shrubs, Dryas x suendermanii and Salix retusa. At the shadier end, Geranium macrorrhizum 'Album' and Potentilla cuneata both became seriously invasive. Although several small alliums and saxifrages thrived, the whole area carried only some 30 species, noticeably poor in this plant-rich garden.
Until this week, the whole scree had become a serious mess and badly needed a total refurbishment.
The next photo shows a cross-section of the soil, revealed as the first plants were removed. Although it is still basically pure gravel, it was interesting how an accumulation of old leaves and moss had added humus to the mix, so that the proportion of humus was now probably 10-20%. The average depth of the scree is about 20-25 cm.
The scree was partially terraced by a line of quite large (about 150-200 kg) limestone boulders, inappropriately so in this river gravel scree! At the outset I decided that I wanted to move these to the periphery of the scree, so that it became more like an extensive raised bed, and the scree became unbroken. The boulders were moved with an excellent, although very heavy 2 m crowbar that I purchased when first building the garden in order to lever very large stones. I find I can move around stones up to 500 kg single-handed using this crowbar.
Three of the four permanent features that were not moved were visible in the last photo, a Rosa heckeliana from the MESE expedition, and two dwarf conifers, Juniperus chinensis 'Echiniformis' (only 20 cm high after 20 years), and Pinus mugo 'Winter Gold'. Abies nordmanniana 'Golden Spreader' features in the next photo. All were deemed too big to move and form foci for the redeveloped bed. The next photo also shows the rocks before they were moved, but the scree cleared of all other plants.
Here is roughly the same shot, after the rocks were moved. The photo following shows how these now match those in the adjoining bed.
The whole area was thoroughly dug over and relevelled before replanting, but nothing was added, so the area is just as impoverished as before. Many of the larger plants were split up, and the worst invaders were not replaced. Some crowded plants from elsewhere in the garden were added, especially silver saxifrages, of which there are now 12 different examples in the scree, mostly mature plants. The final three images in this section show the replanted scree.
I returned home yesterday to find that a number of crocuses had come into flower during my absence, and several other plants had also finally deigned to flower. Sometimes I wonder whether a late October Show might be as well supported as those held earlier in the autumn.
I was most pleased with the first flower on Crocus (biflorus) melantherus. This had been grown by seed collected by Kath Baker in the spring of 2003 from a well-known site south of Tripoli in the Greek Peloponnesos. As this site is dominated by C. hadriaticus, the collectors did very well to find seed of the correct thing!
Here is C. serotinus subsp. salzmanii. I had featured this before, but there are more than twice as many flowers this year. Next comes C. tournefortii.
I have grown a rather leggy, spring-flowering form of the north-African Ranunculus calandrinioides for some years, but last spring I purchased a seedling said to be from an early pink-flowered form. Well, it is certainly early! and pink!
Finally, here is Digitalis minor. This is a Balearic endemic, a dwarf perennial of limestone cliffs, and fairly hardy. It used to be known as D. dubia, and so it appears in Flora Europaea, but the latest edition of Bonnier has this name. I collected seed when we visited Mallorca this time last year, and here it is in flower. It is about 15 cm high, and reputedly perennial..
Oh dear, the clocks go back tonight! From here on in, the garden day stops at 4.30 pm! Roll on the spring!