Gardening: "Take your time over selecting pebbles and picking out shapes"

There aren't many works of art that you can walk over without experiencing a guilty conscience, but pebble mosaics are the exception. From the courtyards of ancient Greece to modern-day gardens, unassuming pebbles have long been used to create colourful, textural focal points which make us pause for thought.

One woman who knows more about pebble mosaics than most is Maggy Howarth. She started off small, creating designs for her own back garden and today is in demand all over Britain and beyond. Commissions have included rose mosaics on Edinburgh's Rose Street, a mosaic depicting a compass at Discovery Point in Dundee and many more in public spaces, country houses and private gardens.

So how does someone go about becoming a professional mosaicist? Howarth says that having previously had a career as an actor, she took up pebble work in her forties, at a time when her son was at school and she thought it'd be better to be based at home rather than travelling around the country doing theatre work. "I loved gardening and I've always been an artist so making things was quite natural," says Howarth. "I first made a piece outside the front door, for fun, as a welcoming thing, and that was it. It took a while to get started because really there wasn't anybody doing it." She says that she experimented with different techniques before working out a method she calls "precast" in which mosaics can be made upside down in moulds before being taken to their final destination. "It means that you can work indoors and take it anywhere, otherwise you're on your knees, which is great fun in the sunshine, but not very practical in this climate."

Howarth has just revised her Complete Pebble Mosaic Handbook (25, Frances Lincoln). It is packed with photographs of her own work, as well as traditional and contemporary work from around the world. It also takes beginners through every stage of design, finding materials and then constructing a mosaic. Howarth says that with the right preparation, it's entirely possible for a beginner to create something worthwhile. "If you are starting out it's best to pick something very simple - don't do anything too complicated or large," she says. "Take your time over selecting pebbles and picking out nice shapes. I'd also recommend working in good weather with plenty of cushions, and if you can adopt a slave or two, even better."

Given that constructing a pebble mosaic outdoors is a time-consuming pursuit, it's no surprise that it's the sunnier countries of the world where you'll find them in abundance. Howarth's book shows examples of lots of international work, including immaculate mosaics dating back to 400 BC in Olynthus, Greece and intricate black-and-white pebble mosaic paths at the Alhambra Palace and gardens in Spain. Examples of mosaics from Greece, Turkey, Madeira, Italy and China also feature, each with their own themes and styles.

"This country is really too far north for people to have gone in for it in a big way," says Howarth. "In southern Spain, they're all over the place. In Turkey there are a lot because it was part of the Ottoman tradition. If you go to China, they do it on a big scale there - you see modern landscaping with big areas of pebblework, developing it from the traditional gardens. I've made it a bit of a study because nobody else was recording anything and it's always very instructive and interesting to see how other people do it."

While pebbles are available to buy, Howarth tends to use locally sourced materials as they work more harmoniously with their surroundings. In legal terms, you have to ask the landowner's permission before removing pebbles, so even if you're just gathering a few from a beach or riverbank, ask permission to keep yourself on the right side of the law. In terms of designing a mosaic, spending time to get the drawings right is well worth the effort. Howarth says that she spends weeks working on designs for her commissions, and says it's always better to take your time rather than change your mind at a later stage. The Complete Pebble Mosaic Handbook acts as a great sourcebook for design ideas - you'll find geometric patterns, floral designs, images of birds, animals, Celtic knotwork, the sun, moon and even mythical creatures. Howarth says that just as a garden is personal, so too is a pebble mosaic.

Howarth identifies four key rules of construction: ensuring a solid foundation; providing side restraints of brick or stone to keep the pebbles in place; setting your pebbles vertically rather than flat and keeping them packed tightly together. In terms of the pebbles themselves, they need to be so hard that they cannot be crushed, shattered or chipped. The sort of fine-grained pebbles found on beaches that will do the job are commonly granites, slate, hard limestones, quartz and flint. Then you need to decide where to locate your mosaic. Gravel and grass can make a difficult surrounding as they'll invade from the edges, but stone paving and bricks work well. Open spaces where wind, sun and rain can help to keep the mosaic clean and dry are preferable to under a tree, where dampness and leaf fall will take their toll. "Of course, putting it where you're going to see it, pass over it and enjoy it is key," says Howarth.

Howarth's book may well inspire you to design a pebble mosaic or two for your own garden. It'll certainly make you look more closely and appreciate any mosaics you come across. She's currently at the planning stages of a design for a large mosaic destined for Livingston. "I've no idea how it'll go, but the idea is to make some poetry for the place - something that people will get fond of and enjoy." If Howarth's track record is anything to go by, the people of Livingston are in for something special.

To find out more about Maggy Howarth's work, visit www.maggyhowarth.co.uk

• This article was first published in The Scotsman on March 26, 2011