Think about the fruit and vegetables you buy. Yes, we’re all told to eat more of them for our health, and so we should, but not all are created equal.

In conventional farming all are treated with varying degrees of herbicides and pesticides and some retain these chemical nasties more than others. The US-based research centre Environmental Working Group (EWG) has published a free guide to those with the most (and least) pesticide residue. The group looked at 44 popular varieties, comparing data from 51,000 tests carried out by the US Department of Agriculture and Food and Drug Administration.

It’s worth keeping a copy of the list in your wallet when you go shopping so at the very least you avoid the worst offenders, which EWG has labelled the Dirty Dozen. They point out that while washing and peeling fruit and vegetables does help remove some residue, it does not eliminate them (besides, with many fruit and vegetables you’d prefer to keep the skin on if you can for maximum nutrients). If you want to minimise your exposure – and that of the environment – to pesticides, try to choose organic when buying the following fruit and vegetables.

Go organic: Strawberries have some of the highest pesticide residues. Picture: Taco-Man23

Apples
Capsicum
Celery
Cherries
Grapes
Lettuce
Nectarines
Peaches
Pears
Potatoes
Spinach
Strawberries

Rare breed: The Romanesco Broccoli is prized for its flavour and beauty. Picture: Artichaud

Rebecca’s garden is replete with heirlooms. Different colours, shapes and sizes, they dot the landscape, sparkling like diamonds when the sun catches them at the right angle.

Rouge d’Hiver, Cherokee Purple, Zucchino Rampicante, Little Marvels, Tonda di Paragi… Their very names evoke the exotic, hinting at journeys of discovery in foreign parts.

Indeed, many of them have come from far afield and are highly prized, although call them by the humble names of lettuce, tomato, zucchini, peas or carrots and the uninitiated may think otherwise.

It is the scarcity of these cultivars that makes them so valued, if not valuable in the tradition of diamonds and pearls.

Before the advent of monoculture farming – growing one crop over a wide area – there were thousands of varieties, for example, of apples to be had. Chances are our grandparents could have reeled off dozens without thinking; most of us would be hard pressed to name more than about four or five.

Large-scale commercial farming generally favours hybrid crops that produce a more uniform look, smell and taste, as well as ones that can withstand the rigours of transportation and storage.

Think about the average tomato you buy; it’s either round or oval, big or small. There aren’t too many green, purple, pink or striped ones to be found in most grocers.

Hunting down heirlooms

But there is a band of people around the world dedicated to changing all that, to hunting down and preserving exotic heirlooms so they do not vanish from our lives forever. People who are gardeners and food lovers like Rebecca can go to for a slice or two of tasty treasures.

The Seed Savers Exchange, a non-profit organisation, estimates it has passed on more than a million such seeds to other like-minded gardeners since its inception in 1975.

Founders Diane Ott Whealy and Kent Whealy began their heirloom collection with two plants from Diane’s grandfather – Grandpa Ott’s Morning Glory and German Pink Tomato – that had been brought by his parents from Bavaria to the US in the 1870s.

Heritage Farm, SSE’s headquarters in Decorah, Iowa, boasts 24 acres of certified organic gardens that puts Eden in the shade. There, you’ll find the most diverse public orchard in the United States, a place where 700 varieties of apples from the 19th century are on display; as well as more than 24,000 rare vegetable varieties, including 500 different types of tomatoes and beans, from as far afield as Eastern Europe.

Although there is some debate about what exactly constitutes an heirloom, it is generally held that the plant must be at least 50 years old (some gardeners maintain the plants should have celebrated their 100 birthdays); it must be self-pollinated or open-pollinated (able to reproduce itself); and, like anything worthy of the name, it needs a history worth sharing.

Take the rare Golden Sweet Pea. Collected at a market in India, it is best eaten small and is a delicious addition to stir-fries. It will also look rather gorgeous in your garden, boasting purple flowers and bright yellow pods.

Then there’s the beautiful Romanesco Broccoli. Prized in Italy, its yellow heads look like cascading coral and those who’ve sampled it argue there is no other in the family that can touch it for flavour.

For another splash of colour, try the Purple Peruvian, a potato highly valued in the South American highlands. Regarded by many chefs as the “gem of the Andes”, this not-so-humble-spud raises your average salad a notch and also makes great chips.

SSE and other companies sell heirloom seeds worldwide, so if you can’t find any of the above at the local grocer – and chances are you won’t – you might just be able to grow them yourselves. And discover a whole new meaning of the word treasure.

Beautiful beet: Treat it kindly and the rewards for your health and tastebuds are rich. Picture: Ayala Moriel

Spare a moment to consider – and pity – the poor beet. It has suffered an inglorious fate over the years. Pickled to within an inch of its life, sliced, diced, ruffled then retained in its jar for years on pantry shelves for its annual outing at Christmas.

It’s no wonder that many consider this overlooked but sensational vegetable is due for its moment in the sun. It’s almost as if the beet, or beetroot as it’s also known in some parts, was designed to be loved, despite its humble roots. Its leaves are heart shaped after all, and it leaves the cooks hands a blushing pink if care isn’t taken.

But somehow, somewhere along the way, the beet’s loveable side was ignored, in favour of boiling it to within an inch of its life before sousing it in harsh vinegars or pulverising it into borscht.

Thankfully, the resurgence in the popularity of beets through top chefs such as Gordon Ramsay and Gary Rhodes has meant that keen cooks have taken a fresh look at this humble root.

Take your organically grown beet – and be prepared to be amazed at the choice out there. No longer are you restricted to the familiar, usually dirt-encrusted purple orb. There are fabulous colours, even stripey variants (Chioggia especially), as if specifically created to add interest and flavour to your plate.

Beets are versatile and kind when cooked; they can be peeled, steamed and then eaten warm with butter, or roasted and diced, ready to be added to a simple salad of feta cheese, lentils and lamb’s lettuce. Just remember to keep the skin on if you want to avoid murderous-looking hands when you handle them cooked, or wear gloves.

Health-wise, the beet could be said to have it all.

Since Roman times, it has been used as a treatment for relieving constipation and fevers, as well as giving oomph in the bedroom, too – it is well known as an aphrodisiac thanks to the high levels of boron it contains. Even these days, such is the strength of its health-giving qualities, some believe that beets and other vegetables high in beta-carotene may provide a key in the fight against HIV and other diseases.

In the 19^th century, beets were known as “blood turnip”, thanks to the way they would “bleed” after cooking, an irony since research has now shown that beets taken in juice form can help lower blood pressure levels.

For chefs and cooks however, the only thing that matters is the taste – and as long as they are organic and properly prepared (ie, not in a jar, swilling in malt vinegar), many would swear there’s nothing finer to offer as a mash, pureed with a slug of sour cream and some chopped dill, and served with strong game meat, like venison.

It is one of the sweetest of vegetables, complementing in its turn oily fish, such as mackerel, as a side salad, shredded with fennel and cumin seeds.

There will still be those who insist on keeping a jar of pickled beets on standby in their cupboard, next to the dill pickle and mango chutney. But to ignore the possibilities of this colourful, ancient and health-giving  little star of the kitchen would be a real crime.