As observed during September 2008
3/9/2008
The original fly paper
Take a look at the semi-tender perennials in the borders to the south of the Glasshouses Front Range. In one corner is the grey-leaved Salvia discolor, a woody perennial from Peru.
The dark, almost black, typical Labiatae flower is sheltered beneath the grey, leaf-like sepals. These flowers have a smell so distinctly blackcurrant you could believe you were holding the berries. A pool of very sweet nectar lies in the throat of the flower.
As the petals drop, the sepals are left intact and wide-mouthed, resembling a fish gasping for air. These flowers are grouped in whorls, known as verticillasters, around the stem.
The stems, as they develop, are green and covered in a highly sticky substance that all manner of aphids, small flies and airborne seeds attach to. Maturing, this substance loses its effect and the stem turns white, as do the reverse of the leaves.
This lax-growing plant reaches to 1m with shoots continually dividing to cover the ground. It is soon defoliated by autumn frosts.
9/9/2008
A gold storm heralding autumn
Amongst the tallest growing herbaceous plants is Rudbeckia 'Herbstsonne', also known in the trade by the English translation, 'Autumn Sun'. This old cultivar is really only suited to the larger garden, bulking into an extensive clump and touching 3 metres in height. It is often thought to be a cultivar of R. nitida or a cross between R. nitida and R. laciniata, both native to North America.
The petals or ray florets appear curled, pushing taller resembling fingers surrounding the mass of disc florets. Opening as a flat ray, the petals are a bright yellow. As these fade and drop, the cone gains a tint of colour. This is provided by the opening of the anthers, a deep purple in colour and best appreciated through a hand lens. At this stage a slight scent can be detected to attract insects for the pollination process.
Suited to the smaller garden is Rudbeckia fulgida var. sullivantii 'Goldstrum', which grows to a more modest 1.2m but still bulks up strongly, as the image shows. This reliable member of the genus provides a storm of golden colour, as the translation recognises.
Its golden yellow ray florets are held on tough, angular, hairy stems. This is lignin production at its best, holding the mass of colour upright through heavy rain and storms.
Which brings us to the rainfall total for August 2008 - a whopping 202.3mm, the highest amount recorded in any month since RBGE started recording weather data. As can be imagined with this amount of rain, sunshine levels for the month are also low at 79.1 hours, with no sun recorded on 7 days; that is almost a quarter of the month with no sun during a period whe we would have expected the bulb collection to receive a summer baking! For more information, see our Edinburgh Weather Station.
12/9/2008
The white flag as summer surrenders to autumn
The group of Anenome x hybrida 'Honorine Jobert' on the edge of the Herbaceous Border is full of white petalled flowers at the moment, taking the inevitable early autumn weather in its stride.
It is a hybrid between A. hupehensis var. japonica x vitifolia, both native to Asia. This is a very old cultivar, raised in the 1850s in a garden in Verdun, France. The cultivar has stood the test of time, continuing to receive good reviews due to the reliability of flowering and the quality of bloom produced.
It is fully hardy, and importantly, resistant to changing weather patterns, and produces growth that needs no support. Many of these qualities that ensure a plant stands the test of time are lacking in flash-in-the-pan cultivars. An object lesson in choosing wisely and planting for effect.
As an alternative, 'Queen Charlotte' is a cultivar with pink petals. It is of the same parentage as 'Honorine Jobert' and was raised in Germany in the late 1890s. Both grow to 1.2m and have a ready supply of flower buds to ensure a long flowering season.The wiry roots take a season to establish then spread through soil making a substantial clump.
17/9/2008
Sweet smell of success - Rosa bracteata
The flower of Rosa bracteata is described by W.J. Bean in his book Trees and Shrubs Hardy in the British Isles as having a delicate, fruity perfume.
From a straw poll of several people in the Garden, most likened the scent to cleaning fluid. It is certainly not the usual rose bouquet. Bean described this plant in the days between the wars when the range of household cleaning fluids were limited and men had a hazy view of kitchen cupboard contents.
This is a strong-growing plant with vicious downward facing thorns. These continue on the leaf petiole and reverse of the mid-rib.
From foliage with a light green gloss the terminal flower buds are produced.
The bracts are covered in a grey down, fat and prominent, opening to 100mm across and revealing a mass of yellow anthers. As the white petals fall, these become a distinct feature themselves.
23/9/2008
A late flowering Saxifraga
Saxifraga cortusifolia provides a mass of tiny white flowers in the most welcome sunshine of a dismal season. It thrives in dappled shade where a moist root run is promised.
This deciduous member of the genus is native to Japan and N.E. Asia. It produces large, fleshy leaves with veins a light chlorotic green.
The tall, waxy flower stem branches into a multi-headed mass of white petalled flowers to 300mm height. Of the five petals on each flower, one protrudes larger than the others like the single feather in a Red Indian head dress.
Once established, it grows into a strong clump, bulking up each year, but does not produce stolons.
26/9/2008
Cool autumn mornings and distant Nerine
As the days shorten and the lawns are laden with dew so the South African bulbous perennial Nerine bowdenii shows its flowers. As regular as clockwork the sudden burst of pink takes the border by surprise and then lasts well into November if no frost damage occurs.
The bulbs, often thought to be on the verge of hardiness, thrive best when planted at the base of a south or west facing wall. In the open border soil must be free draining. At planting set the top of the truncated bulb above soil level. These push leaves out during and after flowering, growing through the winter months. In theory they rely on a summer baking during their resting period. As can be observed from the prolific flowering of the groups in the Garden although this past summer has seen little sun the bulbs still developed and are now flowering well.
As the planting becomes established, by division and multiplication of the bulbs the group can look overcrowded. If flowering is reduced then split and divide allowing further room for development. On the whole Nerine bowdenii is better left undisturbed.
The flower stem is capped by an umbel, as the buds break open they resemble crabs pincers. These continue to expand the six petals forming delicate edges with a very faint scent. The flowers are so colourful and distinctive they are recognisable in the landscape from 100 paces or more.
For previous years' highlights during this month, see the September Garden Highlights Archive page.