Urban gardener and TV presenter James Wong doesn’t have a greenhouse, propagators or teams of gardeners, yet through obsessive trials in his own back garden he has managed to grow a range of exotic fruit and veg worthy of any Michelin-starred restaurant.
He laments that we’ve become stuck in a 1940s timewarp during the ‘grow your own’ revolution, barely moving beyond spuds, sprouts and swedes.
“We don’t eat the same stuff we did two generations ago, so why on earth should we be stuck growing it?” asks the Kew-trained botanist.
“Ironically, the biggest mistake people make is trying to grow exotic crops in greenhouses when they simply don’t need to.”
Wasabi, also known as Japanese horseradish, which is used as a fiery accompaniment to popular dishes including sushi, is easier to grow than watercress, he insists.
Wasabi plants can’t stand the sunshine, but thrive in cool, wet, overcast settings, which makes them perfect for growing in this country.
The edible part of wasabi is its partially buried stem, which takes up to two years to reach full size and flavour, but once you have an established clump, you’ll have a succession of ‘roots’ for many years.
Harvest them when they reach around 10-15cm long - a third of this may be below ground - and grate them fresh at the table, because they will degrade within a few hours of being grated.
Wong has also managed to grow cocktail kiwi, a pint-sized, fuzz-free version of the original, which he says is easier to grow than apples and pears, along with asparagus peas, dahlia yams and callaloo, a Caribbean ‘spinach, on his urban plot.
The Inca berry, or cape gooseberry, imported from Colombia to supply the fancy fruit sections of certain supermarkets, was commonly grown in this country in Victorian times, says Wong.
“The plants can be grown like tomatoes but are not susceptible to blight, are more drought tolerant and you don’t need to prune or train them.”
Plant them against a sunny, south-facing wall in well-drained soil and cover their roots with a thick layer of mulch.
In late summer and early autumn the plants will produce a heavy crop of brown papery lanterns which fall off when they are ripe. The shiny golden berries within taste good as they are or as an interesting ingredient in smoothies, salads and salsas and have up to a three-month shelf life.
Among Wong’s favourites ‘exotics’ is the New Zealand yam, originally from Peru, which makes a much more interesting alternative to the potato.
And even the world’s most expensive spice, saffron, can be grown easily at home. Derived from a particular crocus, C. sativus, which has three distinct saffron threads in each flower, it was grown for more than 500 years in Saffron Walden in Essex, before Spanish imports became cheaper.
Corms, which are widely available, should be planted in late summer in free-draining soil in a sunny site and watered in well.
Blooms should appear in as little as eight weeks and to harvest the saffron, pick the long red saffron threads out of the centre of each flower with a pair of tweezers, put them between two pieces of kitchen roll and dry them out on a hot radiator before transferring them to an airtight jar.