Gardening with Gael: Can anything survive Marg’s sand bank?

23 may, 2022

I remember once reading about a ‘difficult’ bank. Banks, like roads, are inanimate objects so it’s not the bank that is difficult, it is the activities imposed upon it.

Gardening on my friend Marg’s bank can only be described as challenging. A vertical sandhill with little or no access to water, gardening on Marg’s bank is an ongoing test for survival for both the plants and Marg as well I suspect. Discussing plants with Marg usually elicits a frown accompanied by narrowed eyes. ‘Will it survive my bank?’ she inevitably asks.

So conscious are we all of what might survive on Marg’s bank that even the local nurseries are texting me with ideas. ‘I think I have just the plant for Marg’s bank’ wrote Jess from Mangawhai Natives. ‘Check the website for ‘shore spurge’’.

Shore spurge or sea spurge [Euphorbia glauca] is also known as waiuatua. It is a small coastal plant with reddish stems and soft blue/grey foliage. Endemic to New Zealand, shore spurge grows happily on coastal cliffs, sand dunes, banks and rocky lake shores. Tolerating hot dry conditions, it thrives in hardy environments. Sounds like your bank Marg!

Red stems grow from creeping rhizomes. Narrow oblong leaves are distinctive and attractive. Shore spurge is moderately vigorous. Jess showed us the size of a well established plant when we went to collect our order. The plant had good one metre spread. Marg bought five and was so happy we went back and bought five more. I have planted mine around some clumps of astelias. The soft colours of both plants complement one another and the contrast of leaf form makes an interesting combination on the bank. We are fortunate to have well established clumps of astelia banksii all over our property, some under the manuka/pseudopanax canopy and some fully exposed to all day sun. The silvery sword-like leaves provide a wonderful contrast in colour and form to the surrounding bush.

Euphorbia glauca flowers occur at the tips of the stems. The maroon colour sounds attractive but unlike other euphorbias are really insignificant. It is the leaf form that is appealing. I can picture them spreading around the base of the astelias and hopefully, they will be just as easy to look after.

These euphorbias made me remember other euphorbias I have grown in the past. These have had more significant flowers than the ‘glauca’. I remember one with bright green round leaves and flowers of bright orange – Euphobia griffithii ‘Fireglow’ I think it was. It glowed happily in the shade among some vireyas. Although it spread and seeded it was easy to manage as were the yellow and lime-coloured varieties, filling

gaps too readily taken by other weeds. These euphorbias have a wider range of growing conditions, enjoying sun or shade, and damp soils as well as dry.

I am delighted to have discovered these unusual plants and look forward to seeing them flourish on an area I was going to find difficult.

A hardy coastal plant, happily Euphorbia glauca will grow almost anywhere. PHOTO/BIG JIMS