Stephanandra tanakae a deciduous shrub with long arching growth. Native to Honshu Japan where it was seen growing on steep NE facing rocky cliffs at 920m. Here only attaining 1m x 1m in size. In our deeper, more fertile soil the plants are reaching 2m x 2m and producing a mass of small white flowers contained in terminal panicles. Ideally grow in full sun where the flowers are much more prolifically produced than in a shaded situation. Foliage a fresh mid green with a serrated edge.
The fashion to breed tighter more compact plants for modern gardens by passed this species from Japan. Hemerocallis exaltata is a vigorous herbaceous plant, the flower spikes reaching almost two metres in height. Showy, bright yellow trumpets are seen best with the sun on them. Certainly the clump planted in the garden border is visible from a distance away across the Oak Lawn.
A gentleman by the name of Arlow Stout (1876 – 1957) crossed many species and cultivars of Hemerocallis in the United States. An academic who understood the intricacies of pollination he became a prolific hybridiser and writer. Arlow worked at New York Botanical Garden from 1911 until 1948 where he also initiated a study to produce seedless grapes.
Styrax officinalis; a deciduous shrub with the most attractive white flowers. These are produced on the current season’s shoots. Initially a spherical creamy bud that on opening reveals a cluster of yellow anthers held on white filaments. Reference material mentions scented flowers; it is barely perceptible, even on a warm, still, humid day.
The ovate foliage is velvety to the touch and has a vague grey tomentose sheen to the reverse.
A native to southern Europe and the Middle East. Plants were observed growing in southern Anatolia, Turkey in field margins, cultivated areas and on steep slopes at 1098m. Our plants growing near the west gate have signs of winter tip dieback, but nothing detrimental to the plant which has put on good growth through this spring and into early summer.
The herbaceous Peonies; short lived in bloom but once established in the border are you callous enough to dig them out? This cultivar, Paeonia ‘Rose Garland’ dates from the 1940’s, benefitting from a few pea sticks to hold the top heavy growth in place. It repays the gardener and florist with colour from bud swell stage, when they are ideal for cutting to place in a vase, to petal drop. Left in place the seed pods ripen and split open adding interest later in the season.
Let your eye run the length of the alpine wall; an intricate mass of flower is your reward. Petrophytum hendersonii cascades down the south face of the limestone with catkin like racemes of flower. A native to NW USA where its dwarf mat like growth can be found clinging to cliffs and rock faces. The multitude of off white flowers have a slight scent and are ideal to detract from the hideous shades of the dwarf Phlox cultivars belching out lurid shades of red though the diverse range of planting within the limestone mulch.
The bronze foliage cultivar of Rodgersia pinnata ‘Irish Bronze’ is particularly showy when the sun sifts through the leaves. It highlights the shades of colour contrast; deep bronze through light shades and ranging to almost translucent when the direct sun shines at its most powerful. Be sure to take a look at the group in the F beds here at RBGE from both pathways to appreciate the full contrast of colour.
Walking through the garden many variations in foliage colour and form within the genus Rodgersia can be seen. All are herbaceous, growth arising from a thick mass of root that prefers to sit on or just below the soil surface. All Rodgersia species enjoy a moisture retentive soil and a seasonal mulch with organic matter.
May, a month of long weekends and long warm evenings; only partially true this year.
The low temperature throughout May has not been conducive to growth. The student plots are at least two weeks behind in growth compared to previous years. Fleece coverings have helped where seedlings and young plants have been transplanted. The exception is the rows of Broad Beans, especially the red flowered cultivar ‘Crimson Flowered’ which is attracting much attention from visitors.
It is the recently planted bedding Geraniums, or Zonal Pelargoniums as they are referred to, that have suffered from the unseasonably cool weather we experienced through the month of May.
As the attached image shows there is a visible purpling to the leaves in all the plants set out in the Palm House border. Compare this with the image of the Geraniums remaining in the cold glasshouse. It illustrates the importance of hardening off prior to planting out allowing the plants to acclimatise to an outdoor situation. These plants, although going through the hardening off process were not prepared for such prolonged low temperatures. June is not starting well with gales from the west.
The real star this week is Heuchera ‘Firebird’. An herbaceous plant that has produced a mass of flower spikes covered in bright red flowers. Planted as a drift to the north of the herbarium, they have lifted this dreary area with their colour.
Camassia leichtlinii ssp. suksdorfii has long linear leaves as you would expect from a member of the Agavaceae family. This is a stunning perennial that repays planting space in the border with a reliable show of multiple upright racemes, covered in blue flowers. Opening from the base of the spike, the long petals twist together as they senesce.
Enjoys an open situation with a moist root run, yet dislikes waterlogged soil. Native to western north America and generally hardy with us. Once planted leave to their own devices as they resent disturbance.
The second half of May and we hope the frost is finished for the season. Make sure all half hardy and tender perennial stock you are planting out for summer display is hardened off before sinking a trowel into the soil. As you can see from the attached images a late frost followed by early, bright sunshine can have devastating effects on tender young growth. These woody plants sit out in all weather. Trees and shrubs form the backbone of planting and still thought must go as to where in the garden these plants are situated. The large woolly leaves of Hydrangea sargentiana were full of sap which thawed too rapidly as the sun hit the foliage. The tender tips of Pterocarya fraxinifolia will recover, this is a young plant grown from seed collected in Georgia. There are mature, wide crowned, specimens growing successfully elsewhere in the garden. Decoratively, the most noticeable damage is on the young Pieris japonica ‘Variegata’ the showy red shoots are burnt brown, spoiling the display.
The strap leaved Viola spathulata is thriving in the tufa wall that forms the backdrop to the alpine shelter here at RBGE. A native to cliff faces in Iran where the roots push into hairline rock crevices to gain a secure hold and draw up moisture to ensure survival. Here the individual tufa rocks were bound together to replicate these natural limestone landscapes where distinctive flora’s develop.
Covered in the typical viola flowers, V. spathulata is composed of five petals, four facing upwards and the fifth pointing down. Light mauve in colour with a darker colouration in the throat.