Spring starts at ground level - especially in the lea of deciduous trees and shrubs.

These woody plants offer two things - overhead shelter (via the bare branches) and underground drainagethanks to their root systems. Both warm and drain the soil making ideal conditions for spring-flowering bulbs willing to make a precocious appearance.

The gardener can extend this valuable, early-growing territory further by planting right up to tree trunks and lifting the skirts' (that's removing the lower branches) of shrubby plants to allow planting up to the main stem.

Miniature bulbs look perfect tucked beneath a shrub or up against the stem. Where sun strikes fully the jaunty spring-flowering cyclamen (Cyclamen coum) and the winter aconite (Eranthis hyemalis) love to bask at the base of a tree - but perhaps not together. Pink and yellow is a sickly combination.

Luckily some early bulbs respond to being in cool, semi-shade as well.One of the bluest and earliest is Scilla siberica, the Siberian squill. This is a native found in the meadows and woodlands of southern Russia, Iran, the Caucasus and the Crimea. Barely four inches high, it begins to make an impact in bud and the striking strong colour of the flowers is often described as Prussian blue. The wow' effect is immediate, like adding one sapphire to a bowl of ice-white diamonds.

The more-subtle Scilla bifolia, found on the snowline in mountainous Turkey and Southern Europe, needs better drainage and prefers a bit more sun.But S. bifoliawill also tolerate some shade and it provides a shimmering blue with turquoise overtones. It is sometimes earlier than than S. siberica - although forms do vary.Both of these tiny bulbs, which only reach five to 10 cm (2-4 inches) will spread too. Of the two I have found Scilla sibericamore enduring.

Both will provide a carpet of blue given time, making the perfect foil for yellow miniature narcissi. This is because these two colours (yellow and blue) are on opposing sides of the colour wheel. The wide contrast between them always makes for more vibrance. Other classic zingy combinations are red with bright-green and orange with purple.

Miniature narcissi make great garden plants, unlike many of the larger, blowsier daffodils which were bred for the show bench. Many of these were never meant to go in the garden at all. But the classic and early miniatures, February Gold' and Tete a Tete', cannot be beaten for their bright-yellow flowers. Jenny' and Jetfire' are also excellent.

Later-flowering varieties often have fragrance, a more-delicate appearance and a paler colour due to either cyclamineus, tazetta or triandrus blood. Those with fragrant jonquil blood include the soft-lemon Pipit', the golden-yellow Quail' and the white and pink-orange Bellsong'.

Growing a range of narcissi in different shades of yellow, lemon, cream and white will inevitably give you a long season of bloom for the yellows tend to be early and the paler colours later.If you enjoy the subtlety of wild daffodils, with their wispy pale-flowers.

W P Milner' is an excellent taller variety for grass and it looks almost wild in form.

Grape hyacinths (or muscari), those small blue-spiked bulbs are often scorned by gardeners because the most common form spreads far too easily, causing problems.

But there are some fine, less aggressive forms with denser flower spikes. Blue Spike' is a deep-blue double form and Valerie Finnis' is a single Cambridge blue. There is also a new Ocean Magic series with very tightly-packed flowers.

Muscari prefer full sun and, if you have too many, they make a great cut flower. They also provide a wider range of blue and follow the really early blue bulbs. If you are terrified that they will spread, plant them in the lawn.

Perhaps the most cheerful bulb of all is the crocus. In the wild most small species grow in open well-drained positions, the sunnier the better. The smaller-flowered yellow or pale crocuses usually appear first and there are many excellent varieties of Crocus chrysanthus including the pale-yellow Cream Beauty', the purple-flamed white Ladykiller', the silver-blue Blue Pearl' and the lovely mimosa-yellow and plum-purple Jeannine'.

However these small, shallow-cupped crocus are not usually strong enough to push through grass. But C. vernus,found naturally in alpine meadows, has been collected and bred commercially.There are several stunning varieties suitable for grass.

The earliest is Vanguard' a vision of soft lilac and silver, and then come the rest. Jeanne d'Arc' is a pure-white. Remembrance' is the best purple and Pickwick' is a flamed purple. But you must not mow the lawn until the leaves begin to yellow and fade.

The scourge of the crocus is the mouse and they will often decimate a clump and dig up bulbs in the winter. So most gardeners plant some every year and split mature clumps every three years to keep the numbers up.

You will be able to buy pots now from garden centres. But the best and most economical way of ensuring an excellent early-spring show is to order or buy some dry bulbs ready for September planting.

The RHS trialled miniature blue bulbs circa 2005 and they have produced an inexpensive booklet (Bulletin 11) and the results are also available on www.rhs.org.uk/trials Mail order supplier Peter Nyssen, 0161 747 4000, www.peternyssen.com