RAISE the revolution ... elevated beds have changed gardening as we know it. And it's mostly for the better

Revolutions are not generally associated with gardening. Yet one has been steadily building in recent times.

It's all to do with raised vegie patches. Once, a raised vegie garden was made simply by heaping up soil and compost into a raised bed with a channel around the outside for drainage.

All you needed was a spade and some perspiration - and it was free.

Now, in this ready-made, we-want-it-now age, those planning a raised vegie garden are just as likely to head for a hardware chain to pick one up.

It's just a case of choosing - corrugated steel in a range of Colorbond tones, treated pine, hardwood, plastic and even one made of what's called eWood (in fact, recycled plastics), that's claimed to be cheaper than cypress pine and rot-proof.

You can get 'em round, rectangular, square, long and narrow or modular, so new sections can be added as your garden grows.

There's even a Melbourne firm, the Little Veggie Patch Company, that will come in and design one of whatever material you like and to your own specifications.

Some companies will even fill them with potting mix and plant them up for you.

Don't get me wrong, I've nothing against these ready-made raised vegie beds. In fact, I think they're fabulous.

They have literally raised the joys of vegie gardening to a new level.

Suddenly, those denied it because of age or all that bending (who hasn't got a back ache these days?) can get involved without the pain, or without as much pain.

I have an elderly relative whose vegie-gardening days seemed over, until she got a raised corrugated vegie bed two years ago. Now she's in her element again, growing her own fresh produce as she has for decades.

Many of these raised beds are also at the ideal height for the wheelchair-bound.

Another positive is they generally warm up quicker in spring, allowing an earlier start to planting - and plants need not compete with nearby tree roots.

And, unless you have an absolute bounder, your plants won't be trampled by the family pooch.

A downside is that nutrients can leach from a container reasonably quickly because of the continual watering - so regular fertilising, maybe with a liquid fertiliser or even a homemade brew made from cow or sheep manure, is needed.

But then weeding is generally easier - and it's often possible to site one conveniently close to the back door.

So, yes, this is a brilliant revolution.

It's just that I would hate to see the good old-style raised beds, the ones made of railway sleepers, maybe secondhand bricks or recycled corrugated iron disappear.

I reckon there's still a place in gardening for a little nostalgia.

And these beds offer the ideal challenge for rural inventiveness.

What better purpose could there be for that rusted-out old corrugated water tank? Or for those old wooden crates that machinery came in, or old fruit bins such as those used to harvest apples? Or what about old baths, a 44-gallon drum cut in half or an old tractor tyre?

At the Melbourne International Flower & Garden Show, I saw a layered herb garden comprising old car tyres, with each tyre providing the perfect planting pocket.

Now, that was inventive, and it could be replicated so easily at little, if any, cost.

The important thing to remember is drainage.

While most vegies like water, too much will drown them - so always ensure whatever container you plant into has plenty of drainage.

And be wary of using recycled materials, such as timbers, which might have had harmful preservatives applied.

For years, railway sleepers were treated with creosote, now shown to be a carcinogen. And for decades, treated pine has undergone a copper chromium arsenate preservative process.

While numerous tests show it is unlikely to be harmful when used as edging for vegetable beds, for peace of mind you should use arsenic-free-ACQ treated pine (that's if you can find it - it is difficult to source) or something else again.

• Peter Cundall is on leave