In 1993 I planted up a dry bank with a selection of Euphorbia species.
Among these was Euphorbia lambii, which stood out with stout multi-branched stems, bearing heads of grey-green foliage.
For seven years they grew and developed into broad-domed shrubs that became the main feature of the border.
Not only did they add balance to the smaller herbaceous Euphorbia species, but they also linked with the shrubs and trees behind them.
However in 2000, the possums decided to add Euphorbia lambii to their diet. I could not believe that plants with such toxic sap would be so palatable, but every plant was whittled away and had to be removed.
Five years later, though, what I thought was gone, was suddenly back. I realised that the Euphorbia characias seedling that I had allowed to grow in the leaf litter by the edge of the bush, had branched out into a bushy head of growth and was actually a seedling of E. lambii.
Another specimen appeared on the other side of the border and both are nearly 2m tall.
Even better, they have produced four other young seedlings between 20 and 60cm tall and so far remain unmolested.
> See them in the euphorbia border on the edge of the gunnii track in the Botanic Garden's rhododendron dell.
> Bushy heads of foliage with lime green flowers in spring.
> Grows to between 1.5m and 2m.
> Native to the Canary Isles.
> Propagate by seed when fresh.
• Doug Thomson is curator of the rhododendron dell at Dunedin Botanic Garden.
