Spiderworts are very easy to grow and are not fussy

5th Jan 2015

TRADESCANTIA 'RED CLOUD'

There are 71 species within the genus Tradescantia, (family Commelinaceae), all of them native to the American continents. The most garden worthy form loose clumps of grass-like linear foliage and have a tendency towards an informal habit, especially by mid-summer. They can be very floriferous, making them good contenders for use in the border or containers in full sun to partial shade. Spiderworts, as they are commonly known, are very easy to grow and are not fussy as to soil type, actually doing very well in poorer soils and exhibiting soft leggy growth if the area is too rich and nutritious. They are happier in a moist but well drained situation, not being particularly fond of either wet feet nor drought.

Distinctive three petaled flowers are borne in clusters that open progressively over several weeks in colors from white through pink to purple, but mostly in shades of blue. In addition the bright yellow anthers are borne on six hairy filaments that often contrast wonderfully with the colors of the petals. Flowers are closed at night and on cloudy overcast days. Generally by mid afternoon, even on a sunny day, all that can be seen are the buds of tomorrows glory. Flowers bloom for only one day, emit no fragrance, but are still extremely attractive to bees and many other insects including butterflies providing a important link in the ecosystem of the garden.

The genus name honours John Tradescant the elder one of the pre-eminent plant explorers/collectors of the 17th century. Tradescantia is thought to be one of the first North American natives to successfully be introduced to the ornamental gardeners of Europe in 1629, where it met with acceptance and welcome. The common name of spiderwort is most probably related to the gelatinous sap that exudes from broken stems and tissues and hardens into web-like silky threads. Another interesting physiological habit, that can be very useful for anyone living near nuclear power plants, is that the stamens which are usually blue will turn a bright pink in the presence of ionizing radiation. Perhaps an obscure attribute for the garden but definitely an fascinating conversation opener at a garden party!

TRADESCANTIA 'SUNSHINE CHARM' PP21480

Truly beautiful in the early season garden, Tradescantia do tend to get tired, overgrown and yes, messy by mid summer after the peak of their flowering season. If the summer is hot and dry they may enter into a seasonal dormancy which exacerbates the problem. There is a very simple remedy, cut the plants back to the ground when they are no longer attractive. They will soon push out a fresh flush of growth and will usually flower again in the cooler weather of autumn. Alternately shearing the plants by half in mid May, will delay flowering but result in more compact growth.

Most of the cultivars commonly available are the progeny of multiple (natural) crosses between several species T. virginiana, T. ohioensis, T. subaspera being the most prominent parental possibilities as they hybridize quite freely. The plant taxonomist E. Anderson was interested in sorting out the mess that this promiscuity can do to orderly nomenclature, working in the early decades of the twentieth century. This is likely why many cultivars are labelled with the incorrect specific epithet of andersoniana, more correctly is the organization into the cultivar designation of Andersoniana Group.