A lack of confidence and gardening knowledge means that a third of us don't make the most of our garden, according to a new survey.

Nearly half of people buy plants based purely on colour, scent and shape, while one in four aren't seeking advice at garden centres and nurseries, the PlantforLife survey found.

With this in mind, the Horticultural Trades Association is launching a new Plant Advice Guide to help budding gardeners find out what they need to know to create the garden they want.

Topics covered in an easy-to-use format include testing your soil type, as well as descriptions, pictures and suitable growing details for a range of popular plants. Here are a few growing details of some of the plants that beginners may want to incorporate: l Californian lilac (ceanothus): Flower colour: blue, pink and white; free draining soil (not suitable for chalky soil); likes full sun, grows up to 3m. Plant in March/April and October/ November. Flowering time is April-June.

l Cosmos: Tough and resilient, flowering late into the season. Flower colour: pink, white, chocolate brown. Likes fertile, light, very well-drained soils when planted in the garden. Avoid clay. Plant in full sun. Grows to 30cm. Plant in April to June for flowering June/July to November.

l Dahlia: The national flower of Mexico revels in sunny weather. Flower colour: pastels to bright primary colours. Likes fertile, light, very well drained soils when planted in the garden and universal compost when in a pot. Put it in a sunny, open spot. Height varies from 30cm upwards, as does the spread. Plant it in April-June.

l Juniper: Its evergreen, woolly appearance provides an excellent foil for surrounding flowering plants. Flower colour: yellow/green. Tolerates a wide range of soil conditions. Prefers a sunny position, doesn't really like shade. Varies in height from 75cm to 25m. Plant in March/April and October/November.

l Lavender: Perfect for dry conditions and attractive to bees. Flower colour: various shades of blue, pink and white. Will tolerate dry, poor soils but must be free-draining. Put it in a sunny, warm, south-facing spot. Height and spread 30-50cm. Plant in October-March for flowering May-July.