Agapanthus with the dreaded convolvus – the latter is pretty in flower but we do not need it

As you drive around the countryside in January, ponder this: does a sprayed roadside with dead grass and roadside litter look better than wildflowers? And are garden escapes (which takes in most roadside plants and flowers) environmentally worse than repeated application of weedkiller? Maybe it is time we reviewed our attitude to weeds.

It is often said that a weed is simply a plant in the wrong place, though I see Sara Stein is attributed with the extended statement, “A weed is a plant that is not only in the wrong place, but intends to stay.” After all, even weeds are native to somewhere and one country’s treasure can be another country’s problem.

Toetoe beside the new Waikato expressway

A disclaimer first: our native bush and forest are precious and vulnerable to takeover by invasive and aggressive imports. We do not need another old man’s beard (Clematis vitalba) and perish the thought that Japanese knotweed (Fallopia japonica) ever gets a major foothold here. If you are lucky enough to live adjacent to near-pristine native bush, that brings an obligation to be very careful with what escapes your property and colonises roadsides. It also behoves us all to have some awareness of what is on our Regional Council banned and watch lists.

But most of us live in heavily modified environments and I suspect a preference for weedkiller over wildflowers arose from our farming heritage and feeling of obligation that “weeds” should not be permitted to invade precious farmland. Nowadays, when farming has become much more industrialised – a green desert, often, lacking even shelter belts – based entirely on imported grass and feed species, I don’t think that argument holds.

The ugliness of the sprayed verge

Each time we visit Britain, we are entranced by their hedgerows and natural roadside vegetation. Apparently, after major clearance in decades past, there came an awareness that hedgerows contribute a great deal to the eco-system and grants were made available to reinstate them. There is not widespread mowing of road verges, let alone the ugliness of spraying. Would that we had such an enlightened attitude here. In vain do we protest that repeated spraying creates a vacuum into which unwanted weeds move first (notably the invasive, yellow bristle grass in Tikorangi), but it also prevents the ground from absorbing rainfall. Instead, the surface water is funnelled down drainage ditches, washing with it weed spray and any petrol residue from the road into waterways. How much better to have a growing roadside which filters the run-off?

Crocosmia – weed or woldflower?

Roadside vegetation is more interesting visually too, offering flowers and seasonal colour. Add to that a wildlife corridor role and we argue that they can make a significant contribution to a healthy environment. If you are worried about using imported ornamentals, you can encourage native re-vegetation. The native plantings alongside the new Waikato Expressway feature an abundance of toetoe which is wonderfully sculptural and interesting, especially silhouetted against the sky.

But we like the random mix of plants and colours we see. I look for the point where wild hydrangeas on the Otorohanga bypass change from blue tones to pink tones. I guess that marks the transition to limestone country. All our hydrangeas in Taranaki are blue as blue and they thrive on roadsides in a climate where we get summer rainfall.

The white Japanese anemones that flower in the long grass around the country corner where we live make me smile every autumn. Orange-red crocosmia – earlier referred to as montbretia – feature large around here. So too do red hot pokers, fennel, arum lilies and cannas while further north the ox-eye daises, yellow vetch and wild carrot feature more.

And agapanthus. There is a plant that is a great deal more revered overseas than here. It is controversial, actively discouraged and some forms banned in northern regions. Some folk hate it with a passion and it cannot be sprayed out with glyphosate. But truly, our roadsides round here would be the poorer without the summer display. In its defence, we have not seen this tough plant seed down any great distance from its parent in our conditions and it is also very good at stabilising clay banks.

I recall two English garden visitors a few years ago who asked what were the “giant bluebell and what looks like a lace-cap yellow hydrangea” flowering on all our roadsides. The yellow lace-cap was fennel but the giant bluebell had me absolutely stumped until I next drove out. It immediately dawned on me that they were referring to agapanthus. It is not cold-hardy in large parts of Europe and the UK and is a prized garden plant. No wonder they failed to identify it growing wild in abundance here.

Fennel, not lace cap hydrangea

First published in the January issue of New Zealand Gardener.