THE most striking blue note in my Marian border at this moment is provided by Delphinium Loch Leven. The spires of soft mid-blue flowers with white eyes contrast with the flat, pale-yellow plates of neighbouring Achillea Taygetea, and the blowsy, fragrant, white globes of the peony Duchesse de Nemours.

Delphiniums - or larkspurs, to use their common name - have a reputation for being difficult. Certainly the young shoots in spring are favourite fodder for slugs and snails, and with most cultivars the top-heavy flower spikes are easily toppled.

The slug issue can be addressed with a fortnightly dose of ferrous-sulphate slug pellets, which have been given the "organic" stamp of approval. Staking with a few canes linked by soft string around each plant group will provide support. Do this when the shoots are about 30cm tall, and the foliage will soon hide canes and string.

With delphiniums, it is important to avoid buying on impulse, as many of the commonly available cultivars are short-lived in the UK. The Delphinium elatum hybrids are reliably perennial. There are pink and lilac-mauve shades available, but true blue is relatively rare in garden plants; so, as well as Loch Leven, I recommend Faust, with up to 2m sceptres of deep ultramarine semi-double flowers with a darker eye; and the shorter, later flowering Gillian Dallas, semi-double again, and slate-blue with a white eye.

It is the flower-form of the annual larkspur (formerly named Delphinium ajacis) supplies the generic name - dĕlphis being Greek for dolphin. This pretty, easily grown annual now goes under the name Consolida ajacis. The unchanged specific name alludes to its place in Greek mythology: it is the flower that sprang from the blood of heroic Ajax, or Aias.

When Achilles fell at the siege of Troy, Ajax quarrelled with Odysseus over who should have his armour. Ajax won, but was overruled by Athena. This led to the tragic scene depicted on so many vases, when Ajax falls on his own sword. "AI" resembles the markings on the flower, and is the Greek cry of anguish and grief.

Consolida ajacis still grows as a flower of the fields in its Mediterranean homeland, but I was sur-prised to see a whole crop of the characteristically branched stems, with its deeply divided leaves, in the rolling Shropshire countryside. Larkspurs look great in a vase; so the cut-flower market was my first guess at their raison d'être. Then a large sign in the corner of the field put me right. "Shropshire Petals: We grow, you throw!"

In a few weeks, the bands of white, blue, mauve, and pink flowers will be harvested by hand, stripped on to trays, and dried indoors with warm air. They then top up a bank of dried-flower petals which includes rose, hydrangea, cornflower, and lavender. This, in turn, supplies the online demand for natural bespoke pick-and-mix confetti, destined to float gently down over many a happy couple, and biodegrade in a few days. Larkspurs are truly versatile.

www.shropshirepetals.co.uk