The sound of songbirds calling high above the flower stands in Vincent Hall announces the theme of this month’s RHS London Show. One end of the hall is dominated by a square plot designed to offer a choice of desirable residences for wildlife from insect towers and nest boxes to hedgehog houses and toad shelters. Around it is a cluster of stands offering advice on attracting birds, bees and other insects and pond creatures.

The theme spills into the plant exhibitors’ stands too with plenty of woody stumps, dead stems, moss and leaves in evidence and labels indicating the creatures that are associated with specific plants. The observant visitor will find a bird’s nest inside a metal jug (with three life-like stone eggs), fungi on logs, two queen bumblebees which did not survive hibernation this year and a perky looking badger emerging from its holt. The RSPB stand shows how you can transform the smallest patio or balcony into a service station for various creatures by including a short length of ivy hedge, a water basin, some logs and dead wood in a bucket, a tray of sandy soil for solitary bees and wasps, nectar-rich plants such as lavender and a sedum-topped wildlife stack made of layers of different materials that provide nooks and crannies for insects, bugs, reptiles and amphibians. Visitors can take away small bags of wild songbird seed, a wildflower mix specially formulated for the RSPB to attract the insects that provide essential food for young birds, in particular the house sparrow which in London has declined by 70% in the past ten years.

On the Broadleigh Gardens stand, however, there’s a provocative sign that reads "Not all wildlife is wanted". Nursery owner Christine Skelmersdale explains: "I love my wildlife but I don’t want pests like badgers and squirrels. The RHS needs to distinguish between good and bad wildlife." Every year a badger digs up hundreds of bulbs in her garden – this year she lost 3000 crocuses to this determined night-time visitor. And the squirrels, which also make serious raids on her bulbs, are on her list of garden pests too. Last year she deliberately left out some tulip bulbs for them to eat: instead they buried them randomly round the garden and then clearly forgot where they had planted them. As a result this year she has pink tulips coming up randomly all over the garden. Presumably the RHS judges did not take exception to her sign as they awarded her superb planting of spring blooms – including the shade-loving brilliant white Sanguinaria canadensis f. ‘Plena’ - a gold medal.

From a horticultural perspective the show is a celebration of the wealth of spring flowers and blossoms we can grow in the UK, from airy amelanchiers and cherries to diminutive epimediums, primulas and the perennial pea Lathyrus vernus. On the D’Arcy and Everest stand individual bricks, trays, pans and traditional stone troughs are planted up with an assortment of exquisite sempervivums ranging from oxblood ‘Jamberlane’ to dusky pink ‘Virgil’ and apple green ‘Anke’. Cut stem display of old varieties of daffodils and narcissi includes the perfect buttonhole orange-centred ‘L’Innocence’ and a dainty pale lemon double Eystettensis that dates from the beginning of the 17th century. One of the oldest plants cultivated as an ornamental, the bright orange Crown Imperial fritillary, makes a showy splash on the Jacques Amand stand but gardeners who prefer softer, more subtle blooms will be drawn to Fritillaria raddeana, one of the earliest fritillaries to flower in this country, with a ring of greenish buds that open to pale cream and exude a sweet fragrance, and to F. Sewerzowii with nodding bells of greenish purple outer petals and bronze tinted centres on columns of glaucous leaves.

There are further varieties of small fritillaries on display in the Linley Hall where members of the Alpine Society offer their lovingly tended pots of flowering bulbs in competition.

The RHS Greener Gardening Show continues today 10am-5pm, RHS Horticultural Halls, Greycoat St, SW1 www.rhs.org.uk/londonshows