Shady whites

Sunday, 01 November 2009

Trachelospermum jasminoides

My garden has entered something of a white phase at the moment. I have never dared to create an actual white garden, but November seems to be the time when lots of white flowers bloom.

White can be a tricky colour to use in the garden. In sunny spots, stark white flowers can be dazzlingly glary, like something out of a washing powder ad. White also seems to jar with some colours and distract attention from others by its presence. There are also different 'shades' of white, which can look wrong when they are all herded together in the name of a 'white garden'. In shady places, however, the introduction of a few white flowers can be effective, bringing lightness into the gloom.

Trachelospermum jasminoides

I always wanted a verandah swathed in star jasmine (having once seen such a sight in a magazine) and finally I have one. Our shaded back verandah is transformed into a white flowery bower in November as Trachelospermum jasminoides (ht 6m) bursts into a profusion of bloom, scenting the air all around with its sweet fragrance. This evergreen climber is very useful for shaded garden areas. It is not as rampageous as common jasmine (Jasminum polyanthum) and is quite slow to establish. Once it takes hold though, you do need to prune it back annually after flowering, as it gets a little bold and sends its tendrils beyond its appointed boundaries. It can be trained on wires in patterns, used as a groundcover or as a clipped edge for garden borders.

A white mophead Hydrangea in bud

Beneath my verandah, the shaded Hydrangea border is coming into bloom, with several white specimens. I love white flowers that begin their lives suffused with greenish overtones, as many of the mophead Hydrangea do. I think this greenish effect looks pretty with more pristine white flowers nearby, such as the renga renga lilies (Arthropodium cirratum, ht 60-90cm), which are now in full flight.

Arthropodium cirratum (left) with Zantedeschia aethiopica

This New Zealand plant is a wonderful addition to a shaded border, even where the soil is quite dry. The broad, arching foliage is attractive year-round, then in November, tall spires open with myriad white stars of bloom, echoing the star jasmine which flowers above them. The cultivar 'Matapouri Bay' (ht 70-100cm) is said to be a good form and there is a dwarf version called 'Te Puna' (ht 30cm). A pretty little shade-loving groundcover, Saxifraga stolonifera (ht 20cm) has flowers a little similar to those of the renga renga lily and at the same time, so I like to grow it nearby. It has beautiful silver-veined round foliage. I think white flowers look stunning with silver foliage and if I had room in this garden bed, I would add in some of the shade-tolerant Plectranthus argentatus, with its superb silver velvet leaves.

Calla or arum lilies (Zantedeschia aethiopica, ht 60-90cm) are one of those old-fashioned plants which are often spurned, but they can be so useful in a shaded garden bed and bring a bold white form and texture as a contrast to the dainty flowers of the renga renga lily. The calla does self-seed, so it is important to deadhead these as soon as blooming is over. There is a lovely greenish form, called 'Green Goddess' which I like to grow amongst my Hydrangea.

An ageing double hellebore

Some flowers age to green, such as the hybrid white hellebores (Helleborus x hybridus), and I also have these growing amongst the other white flowers in my shaded border. They are pretty with the green-flushed white bells of Solomon's seal (Polygonatum x hybridum), which is still in bloom.

White flowers can be enhanced by growing them with white-variegated foliage, an effect known as 'colour echoes', which I read about years ago in a book of that name by Pamela Harper. In my shady white border, I have used a green and white variegated leaf Hydrangea, the variegated form of Iris japonica and the variegated-leaf white honesty (Lunaria annua var. albiflora 'Alba Variegata') to achieve this. There is something about the pairing of a colour flower with a leaf colour that I find quite compelling, and it is fun to apply this idea to lots of other coloured flowers in the garden as well!