Wildflowers are just blooming marvellous!

A trial planting of roadside wildflowers is brightening motorists' journeys while helping to keep down weeds and save money. LIBBY MIDDLEBROOK reports.

Driving down the Southern Motorway can be a real drag with nothing better to distract you than a pylon.

Since July, though, motorists have been entertained by a corridor of wildflowers, planted beside the southern end of the motorway near Bombay.

The grassy plains that used to divide north- and south-bound lanes have been transformed into a nest of colourful flora, with only the odd weed to spoil the view.

The country's highways authority, Transit New Zealand, is responsible for the bonny display, which it hopes will reduce its gardening maintenance bill.

The wildflowers, imported from Texas and California, could pop up around the country if they prove to hamper weed and grass growth over the two-year trial.

"What's really driven this is the maintenance savings we will achieve; but at the same time, they're very pleasing," said Philip Sutton, Transit's regional highway engineer.

"People have called to tell us how they enjoy going to work now. One person even uses the motorway instead [of other routes] because of the wildflower display."

Since the early 1930s, wildflowers have been planted along highways in the United States to reduce maintenance costs and sooth impatient motorists.

On some stretches of road, average traffic speeds have been reduced by 16 km/h.

The flowers have become an institution in the US, and festivals are now held each year in California to celebrate the early blooms.

Transit heard about the concept two years ago, through Tauranga-based company Wild Flower World, which has been importing the seeds - at $150 to $400 a kilogram - for the past five years.

Local authorities have already used the flowers for cemetery beautification, and fruitgrowers have also planted them to attract more bees to their orchards. Transit ran a similar motorway trial in Auckland two years ago.

The 25 types of annuals and perennials found along the Southern Motorway today were already growing wild in New Zealand before the seeds were imported. Species include a red poppy, Papaver rhoes, a blue flower traditionally found in cornfields, Centaurea cyanus, and a pink flower with wide petals, Cosmos bipunnatus.

It took Transit more than four weeks to prepare the 70,000 sq m of soil for planting, and only unmodified species have been introduced. Nearly all flourish in the infertile, shingly soil found alongside many roads.

Some Northland highways are also involved in the trial, which has attracted the interest of Melbourne's highway managers.

"The seed mixes are a bit like a painter's pallet," said Wild Flower World director Geoff Brunsden.

"We might plant early spring blues and pinks and then by summer have introduced the slower-growing golds and oranges. We try to tailor a mix of three to five months of changing colour."

The iridescent confection sways between the traffic lanes like colourful seaweed on the bed of the ocean.

It is tempting to stop and scuttle across the road to pick a posy of flowers, but that sort of behaviour will ensure their demise, said Transit.

Mr Sutton said the organisation was monitoring traffic to see if motorists were stopping for flowers, but had not had any problems to date.

"It is one of our biggest concerns, that motorists will start pulling over and cause a safety hazard. If they do, we will have to remove them."

Transit is considering running an education campaign to warn drivers. The trial is likely to be extended to the Northern Motorway and Auckland City over the next 12 months.