A word to the wise: respect your elders for best results

There are many stories that might be true about elderberries. The juice of the elderberry (Sambucus canadensis) may help reduce the severity of various respiratory viruses like influenzas. Sadly the active ingredients in elderberry depend on the cultivar, and how and when it was grown, including "was it a cool wet year or a hot drought?".

I'm adding a slug of elderberry juice cordial to the jug of water currently on my desk, not because I have the flu (I don't) but because there's an open bottle of it I don't want to waste, and it tastes good.

It's probable there are many excellent medicinal qualities to elderberry juice - most dark-coloured fruits and veg have a range of healthy substances, and elderberry's dark blue/black juice is surely as healthy as prune juice, or blueberries ... unless it isn't.

One problem with knowing exactly what medicinal properties elderberries have is that the bushes grow easily from seed, and so have much more variability than plantations all grown from cuttings or clones of one productive plant that has been closely studied. We have half a dozen elderberries here, and all of them differ in fruit size and time of flowering.

My first elderberry tree flowered wonderfully, but never set fruit. The gardening books I consulted stated that elderberries didn't set fruit in hot climates. "Aha", I said to myself and anyone who inquired. "The summers are just too hot for elderberries to set fruit."

I did make elderberry cordial and elderberry champagne from the blossom. Elderberry blossom sometimes has a natural yeast associated with it that ferments. My "champagne" bubbled, but didn't taste of much except the lemon juice and sugar added to the flowers. The elderflower cordial was just vaguely floral. You need to pick elder flowers when they are still white if you plan on cooking them - once they turn cream coloured they small of cat's urine. You will also need to strip the flowers from the stems, as the stems are toxic. Another legend says that drinking elderflower cordial will help soothe your sinuses, though I've never met anyone who found that remedy worked for them.

I'd been growing fruitless elder flowers for about 10 years when I met my first heavily laden tree of elder fruit - in Bundaberg, during an extremely hot drought. The "wont set fruit" myth went out the window, and I came home with a purple-stained handbag and elderberry seeds. The new bushes grew fast, giving fruit in their third year, and they have fruited magnificently ever since. Lesson one with elderberries: don't buy one unless you know it's fruited.

Once you've got a potentially fruit-bearing tree, elderberries are a gift for the brown thumbed gardener. Plant them in full sun or dappled shade or even in a pot on the patio as long as it doesn't get full afternoon sun that shrivels everything except cacti. Elderberries grow from a seed or a cutting, taken any time from now till late spring - snip off 60cm or so, place in damp sand, keep moist in dappled shade, and wait. Hormone rooting solution may help the cuttings take but shouldn't be needed. Plant out the following year.

Bushes grow to about three metres high and wide, with masses of white blossom that turns cream in spring, followed by green berries that turn rich purple from mid to late summer, depending on the weather. They're ready to pick when every berry in the cluster turns purple - don't pick them before that, as the green berries may be toxic.

In fact the ripe berries are toxic too. They also taste bitter, so you are unlikely to be tempted to snack on a few. Yes, I have tasted them, proof that one ripe elderberry, from that particular bush, in that particular year, wasn't enough to kill one particular adult female. Do not follow my example. Boil your stemless berries in water for half an hour, then strain off the juice and compost the residue. Freeze the juice, or add sugar to taste and bring to the boil again to help preserve the juice in the fridge, or make elderberry wine. Throw the juice or juice products out if they ferment or turn mouldy.

There is one bit of elderberry bad news I am absolutely sure about - you need to pick the berries off the toxic stems before cooking and this takes ages and leaves you with purple fingers. All the rest of the elderberry plant is poisonous too, though that shouldn't put you off growing them, as many of our garden ornamentals, from daffodils to oleander, are toxic. Just don't eat the daffodils - or the elderberry or rhubarb leaves. For that matter, the spuds are the only edible part of a potato plant. (I do wonder who first thought of cooking and eating the roots of a poisonous flowering plant. Were they brave, inspired, foolhardy or starving?)

Elderberries sucker, so be prepared to cut them back. Birds may spread them, too - haul yours out if there is any sign of them turning feral. But even if you don't use the berries, the bushes are pretty all year round, and survive both droughts and wet soil. You can also tell visitors that according to legend, elderberries grow best in the gardens of the wise.