True blue flowers are few and far between for most of the year, but luckily March and April provide a wealth of miniature blue bulbs. Most of these measure less than nine inches in height and they are happy to grow in sun or part shade as long as the drainage is adequate.

Some can be invasive, so choosing varieties and where to plant them wisely is advisable. Help is at hand. In 2005 The Royal Horticultural Society conducted a trial of all Little Blue Bulbs, all members of the Hyacinthaceae, and there is an informative bulletin listing the AGM winners. This can either be downloaded from www.rhs.org.uk, or ordered from RHS Wisley for £2. (Send an A4 SAE to The Trials Office, RHS Garden Wisley, Woking, Surrey, GU23 6QB. Cheques to be made out to Royal Horticultural Society.) Among the most versatile blue bulbs are the grape hyacinths, or muscari. They are found naturally in a variety of locations including an area around the Mediterranean Sea that stretches from Spain to Morocco. Many species originate from Turkey, while others are found in the Caucasus.

Admittedly some produce offsets at an alarming rate, so care must be taken about where you plant them and which you choose to grow. But in Holland I have seen a river of blue muscari flowing through a garden and in this position an ability to bulk up well is welcome. It’s also worth remembering that muscaris make excellent cut flowers and they also please the bees. M. armeniacum ‘Saffier’ AGM (a two-tone violet and pale-blue) and ‘Christmas Pearl’ AGM (a strong violet-blue) bear conical spikes of 50 flowers and each is rimmed in white. These need dividing regularly after flowering otherwise, when the clumps get too large, the leaves swamp the flowers.

The brightest blue flowers are found on M. azureum AGM , but it does spread quickly. There is a white form that is slower, and both have a narrow spike that opens from the bottom – almost like a miniature foxglove.

I also like two pale Cambridge blue hybrids. One is ‘Valerie Finnis’, named after the late lady gardener who played a vital role at Waterperry Gardens, near Wheatley.

The other is usually sold as ‘Baby’s Breath’ but it should be called ‘Jenny Robinson’. Both have tubular flowers with a hint of green. The Dutch variety Muscari aucheri ‘Ocean Magic’, pictured above, (from Thompson & Morgan) has soft blue flowers finely edged in white and this is one of the slowest to increase. Scillas normally flower two or three weeks before muscari and I grow lots of Scilla siberica, also known as the Siberian squill. The pendulous cup-shaped flowers are a deep cobalt-blue and this sparky little bulb will flower in shade and sun.

The neat foliage is a vivid-green and this scilla will spread by self-seeding although I have never found it invasive. Allowing bulbs to set seed can be an excellent idea because viruses rarely get passed on through the seed line.