Testing Drought Tolerance at Sparoza
by Sally Razelou
Photographs by Davina Michaelides
For the full text of this article see The Mediterranean Garden No 59, January 2010
Some parts of the garden of Sparoza, including 'Derek's Garden' and the hillside are not watered in summer. In sumer 2008 Sally Razelou decided in addition to stop watering the border surrounding the 'threshing floor' in order to test the drought-tolerance of the species planted there. The plants were subject to additional stress because unusually, after 33 mm of rain in three consecutive days in the third week of September 2008 there was no further rainfall at all until November 17th.
This Ruscus hypoglossum received no water all through the summer.
In September 2008, it remains green and shows no signs of stress.
Artemisia arborescens in the 'threshing floor' border in September 2008.
This border was not watered at all during the summer of 2008 (the watering system
that can be seen in the photograph was disconnected). The Artemisia is so severely
stressed that it looks dead, yet it revived once the rains started in November 2008
and is still alive today.
Convolvulus: Convolvulus oleifolius in 'Derek's Garden'.
This plant survives without any water in summer, although by September
it is looking a bit sparse. It fills out again with the winter rains.
Euphorbia dendroides in the 'desert', the driest and most inhospitable part of the garden.
This plant survives without any summer water because it is summer-deciduous, i.e. dormant
and leafless through the hot dry period. With the rain that fell in the third week of September
2008 it has started to put out new leaves. By winter it forms a perfect green dome.
Where the 'threshing floor' meets the 'desert': on the right of the photo the white stems
and narrow leaves of the Greek native Ptilostemon chamaepeuce can be seen growing
in the shelter of Agave americana and a carob tree (Ceratonia siliqua). On the left a
pistachio tree (Pistacia vera), to the south of them, provides a little shade to Artemisia
arborescens and Lavandula dentata.
On the unwatered hillside Pistacia lentiscus has remained green and
throughout the summer; this photograph was taken in early
October.The pines are Pinus halepensis.
Euphorbia acanthothamnos looks dead when it is dormant in summer but
comes back to life as a thorny green cushion with the autumn rains.
This Ptilostemon chamaepeuce in the 'threshing floor' border looks miserably
stressed in summer; nevertheless it is a Greek native plant adapted to hot, dry
and recovers each autumn to produce its mauve thistle-like flowers in spring.