Scrupulous sculpting

The Jerwood Charitable Foundation is the fairy godmother of the arts, magicking up a series of munificent prizes, and with a wave of its magic chequebook fostering talent across the board, from textiles to painting and, as of last year, sculpture.

The inception of this newest award is timely - sculpture has long been losing out to its more ephemeral sister art form, installation, and the £25,000 prize (£5,000 up on last year's winnings) recognises a very particular, and necessarily rigorous discipline -outdoor sculpture.

As well as producing drawings, plans, written statements and, if they make it to the shortlist, a maquette, applicants have to ensure that their proposal will be able to weather the elements in the Jerwood Sculpture Park at Whitley Court, Worcestershire, where the winning entry will nestle among works by the likes of Elisabeth Frink and Antony Gormley.

One of this year's shortlisted artists, Michael Shaw, has already had to amend his design for a cylindrical, membrane-like figure of eight on learning that the transparent acrylic he had hoped to use would not be durable enough. There is no age limit attached to the prize, instead, artists must have left art college within the past 15 years, suggesting that sculptors require a lengthy apprenticeship.

Most of the eight shortlisted artists are fresh out of post-graduate degree courses, but newcomer James Hopkins has already attracted critical attention. His proposed 'Integrated Assemblage Of A Greenhouse Around The Structure Of A Tree' is just that, an aluminium-paned greenhouse built around a large tree, its top felled and its midriff protruding from the roof. Alluding to sources from Jack's giant beanstalk to Dorothy's tornado, Hopkins attributes multiple meanings to his work, but misses the obvious link with fears over GM crops.

When it comes to it, he expects the viewer to put in the imaginative leg-work and mull on just what might be going on inside his shiny silver structure. Nature is also given a man-made edge in 'Dendrite', Simeon Nelson's proposal in which he tops a pixilated, machine-readable pattern for a tree in Hyde Park with the wintry silhouette of bare branches, all cut from steel.

Alison Gill is the only woman on the shortlist but one of several artists who aim to introduce a note of levity to the grandiose surrounds of Whitley Court. Her lawn-based 'Fibonacci Rabbit Generator' applies the numbers in the Fibonacci series to rabbit breeding, organising pairs (the male lounging atop a rather flattened looking female) in the form of a rainbow-coloured family tree. You can already hear the shrill voice of every passing child: 'Mummy, what are those bunnies doing?'

Meanwhile, Gereon Krebber's 'Tin' is an irresistibly witty creation on paper, but the maquette is disappointing, resembling nothing more than a burgerless bap. Likewise, Canadian-born Noah Sherwood's sketches for his bright, gangly structure cast from furniture and bric-a-brac are deliciously grubby with smudged pencil and smears of bright colour, but the maquette, although it has a certain Magpie allure, lacks conviction.

It seems unfair to judge these works by their maquettes, yet that is precisely the task that befalls Jerwood's panel of experts. Whichever artist walks away with the prize, this show offers an engaging glimpse into artistic process.