Good gardeners are always thinking in terms of effective flowering sequences. When one plant starts to fade, we want to make sure there is always another plant waiting in the wings to rise and take its place. This is by no means an easy thing to achieve. There is an art to it that can take years of trial and error to get right, especially since there are many variable factors, and plants, being living things, do not always perform as precisely as the label says. However, with bulb planting, it is a different story. It is possible with careful selection to plant a scheme that will provide a continual and seamless sequence of blooms from early spring through to summer. Is it worth doing? Absolutely. A garden without a full complement of spring-flowering bulbs is seriously under-powered. Here's how to achieve a symphony of spring colour from February to May

.  EARLY-SPRING (FEBRUARY TO MARCH) Start your sequence with snowdrops. Your best bet is Galanthus nivalis. Plant in large numbers and add a little lime to the soil. Other totally reliable, early-spring performers for getting the season up and running include winter aconite (Eranthis hyemalis), dwarf irises (I. danfordiae and I. reticulata), glory-of-the-snow (Chiondoxa luciliae), Grecian windflower (Anemone blanda) and two kinds of squills -- Scilla siberica and the striped squill (Puschkinia scilloides).  Of the first-flowering daffodils, 'Rynveld Early Sensation' and Narcissus 'Lemon Beauty' are two excellent picks, both flowering weeks before any other daffodil. .

Crocus, of course, are indispensible for early colour. These can be liberally sprinkled all over the place, especially on sunny banks and even through lawn areas   EARLY- TO MID-SPRING (MARCH TO APRIL) The next category provides flowers for up to eight weeks from the first weeks of March to the middle of April. Top choices include the checkered lily (Fritillaria meleagris), super-fragrant hyacinths, and all the various species, Fosteriana and Kaufmaniana tulips (often sold under the generic label "botanical tulips"). Popular are 'Lilac Wonder' and 'Eastern Star' but new this year is 'Peppermint Stick'(cherry red with a white inner petal.) Top cultivars of T. fosteriana are the Emperor series (orange, pink, red, white and yellow) while 'Ancilla', 'Chopin'

and 'Showwinner' are highly rated types of T. kaufmaniana. Great for containers are the single early tulips, especially 'Princess Irene,' 'Beauty Queen' and Christmas Marvel,' but there are also double tulips that have a reputation for sturdiness. Look for 'Monte Carlo,' 'Orange Princess' and 'Schoonoord.' Cupped narcissus such as 'Ice Follies,' 'Barret Browning,' 'Salome' and 'Carlton' are also good picks, along with the more traditional-type trumpet daffodils like 'Mount Hood,' 'King Alfred' and 'Dutch Master.' For fragrance, the poetaz narcissi pop up in early-to-mid spring. Must-haves include 'Bridal Crown,' 'Geranium' and 'Cheerfulness.'   MID-SPRING (APRIL) For blooms from mid- to late-spring (April to mid-May), the rockery narcissus are lovely naturalizers. Some like 'Quail,' 'Thalia' and 'Segovia' have fragrance. These mostly grow 20 to 25 cm (8 to 10 inches) high. All the various types of grape hyacinth (Muscari) put on a totally reliable show in April along with many of the novelty narcissi such as 'Tripartite' and 'Lemon Beauty,' a new butterfly-type with creamy petals and lemon-yellow star in the centre.

LATE-SPRING (APRIL-MAY)   Flowering from the end of April through May are all the exotic tulips: Triumph, Darwin, Lily, Fringed, Peony, Parrot and so on. These are delicate hybrids that put on a great show but sometimes do not regenerate, unlike the species types which return year after year. They work well with the later- blooming fragrant miniature narcisssus like .

'Hawera,' 'Sundial' and 'Baby Moon' and late-bloomers like the summer snowflake (Leucojeum aestivum) and the most fragrant and last daffodils to bloom, 'Poeticus Revurvis'   FINALE To complete your spring-to-summer sequence and lay the foundation for impressive flower displays from the middle of May into June, find room for camassia, Dutch iris (look for 'Silvery Beauty' and 'Tigermix') and ornamental onions (Alliums), notably A.

christophii and A. aflatunense. But don't stop there; keep going and put in all the other novelty alliums like A.bulgaricum and A. azureum as well as stalwarts such as A. phaerocephalon to stretch the display into the heart of summer. At this point the baton gets passed to the casts of summer flowering bulbs such as Asiatic, trumpet, tiger and Oriental lilies, which are usually planted when they are more available in early spring