Gardening brings unexpected and delightful rewards. Just when the garden needed fresh cheer, I found, weeding a neglected pot, the bright purple flowers of saffron.
Saffron is a purple-petalled, autumn-flowering crocus. It's the crimson stigma, the female flower part that receives pollen, that is harvested, dried and used as a spice. Each saffron corm bears up to four flowers and each flower has three threads (styles) carrying the stigmas.
Imagine harvesting these by hand, next time you see a tiny packet of saffron with an outrageous price tag. By weight, saffron is the world's most expensive spice, so growing your own obviously makes sense.
It's a great crop for a large pot or barrel, as good drainage and full sun are important. A pot can also be moved under shelter if it rains during harvest season (as it often does in April), because rain can spoil the flowers.
Saffron corms are not commonly available in garden centres, but a quick internet search netted several saffron farms selling them by mail-order, though most are dispatched for planting in summer time.
I planted the corms about a year ago and frankly wasn't sure they were still alive after our dry summer. The pot got occasional water, probably about once a month, and had been colonised by self-sown borage. But the leaves and flowers of the low growing crocuses appeared beneath the borage, about a week after drought-breaking rains ended our baking-hot summer.
Like many other autumn- flowering bulbs and corms (colchicum, naked ladies, nerines), saffron comes from parts of the world with hot, dry summers, during which the corms are dormant underground. Autumn rains stimulate them to produce leaves and flowers. Rain in spring is also said to be important as that's when the plants are producing offset corms underground. Each corm lives only a year but makes up to 10 offsets.
Various crocus species grow naturally between Italy and Kurdistan, but the saffron crocus, C. sativus, is unknown in the wild. It is a sterile form, unable to produce seed. So whether saffron was purposely bred for its outsized stigmas (possibly in Bronze Age Crete) or was a natural mutation, brought into cultivation from the wild, the only way to propagate it is by dividing up the corms.
Saffron has a fascinating history. Its pigments have been found in 50,000-year-old cave paintings in Iraq; Cleopatra used it in her baths as an aphrodisiac and perfume, while Alexander the Great bathed in saffron tea to heal his battle wounds. Saffron has been used for dyeing cloth a warm golden orange and for perfume and medicine, as well as in cuisines from India through Persia to the Mediterranean. The Moors brought it to Spain, where it gives paella its traditional bright warm colour and slightly bitter flavour. Medicinally, saffron tea is said to be good for depression.
In New Zealand, saffron is grown commercially in Central Otago, Wairarapa, Canterbury and Marlborough. It likes low humidity, winter chill and a hot, dry summer.
Harvesting takes place for five to six weeks from the beginning of April; stigmas must be picked within 48 hours and dried quickly to retain maximum colour.
- The Dominion Post