Presenter biographies: J to L

It's been said that her enthusiasm for plants would make even the least green-fingered person sit up and take notice! Carol Klein is the owner of a thriving nursery, and she also writes regularly for the gardening press. She became presenter of Gardeners' World in 2005.

Carol's garden is a south-facing slope on heavy clay. She's been gardening there for about 25 years. "There's never been a grand design," she says. "It's just evolved over time and I'm always making changes. One of the most recent has been to replace a conifer hedge with a native one. Hopefully this will encourage more wildlife into the garden."

She's very lucky as one half of her garden is sunny and the other is shady, so she can grow a wide range of plants. In spring, the shady side attracts all the attention when plants such as pulmonarias and hellebores fill it with colour. Then in summer, the sunny area comes into its own.

There's an interesting history behind why Carol opened a nursery. She initially propagated plants because she couldn't afford to buy the ones she wanted. She grew so many that a friend suggested she sell the spares. Carol followed the advice and took a stall at a local market. Eventually people began going to her nursery instead.

There's nothing Carol loves more than hearing how her plants have done, or better still, to see them in someone's garden.

Chatting about her favourite plants and styles of planting, Carol says: "Reliable performers, such as astrantias, campanulas and hardy geraniums, are the ones that appeal to me most. If I had to name a favourite, it would be Geranium psilostemon. It's always changing, from red shoots in the spring, to pink flowers in the summer, and red-tinted leaves in the autumn. I love naturalistic styles of planting. I've been developing 'wave planting' in my own garden, which aims to get movement into a small space."

If Carol had to choose a favourite garden, it would be The Garden House in Buckland Monachorum, Devon. "The planting's wonderful. It's developed beautifully over the years and one of the nicest areas is the wildflower meadow. I also love the fabulous views of Dartmoor."

As a schoolboy, Roy Lancaster compiled a checklist of wildflowers growing within a ten-mile radius of his home town of Bolton, Lancashire. He's been involved with plants ever since.

Roy's interest in plant exploration has taken him round the world to countries such as Georgia, Chile, Iran, Turkey, New Zealand, Brazil, Ecuador, Japan, North America, South Africa, Malaya and China. He's been a member of expeditions to Nepal and Yunnan, China, and has published accounts of both in his books A Plantsman in Nepal and Travels in China.

His career in horticulture began at Bolton parks department, followed by two years as a student gardener at the University Botanic Garden, Cambridge. In 1962 he joined Messrs Hillier & Sons of Winchester and rose from catalogue compiler and horticultural botanist to become the first curator of The Hillier Arboretum. In his 18 years with Hilliers, he was involved in many exciting projects and played a major role in the preparation of Hillers Manual of Trees and Shrubs, first published in 1971.

A member of the Royal Horticultural Society for almost 40 years, Roy is vice-chairman of the society's Floral Committee B and a member of several other committees. In 1972 he was awarded the society's Gold Veitch Memorial Medal for Services to Horticulture, followed in 1988 by the society's highest award: the Victoria Medal of Honour.

In 1980 he became a freelance writer, lecturer and broadcaster. Roy's published a number of books, while contributing to a range of gardening periodicals, including BBC Gardeners' World Magazine. He's a Fellow of the Institute of Horticulture (IoH) and in 1996 was one of the first recipients of the IoH Award for Outstanding Service to Horticulture.

He's lectured around the world and has taken part in a number of TV programmes, including Gardeners' World and is a regular panellist on BBC Radio 4's Gardeners' Question Time.

In the 1999 New Year's Honours List he was awarded an OBE for services to horticulture.