BEFORE you chuck out your old gardening tools or that urn you inherited from your grandmother, check out their value because Jonty Hearnden, presenter of the BBC1 show Cash In The Attic, says you could be sitting on a goldmine.

He reckons you may be able to sell anything from old paving slabs to large concrete urns, ancient tools, aged weathervanes and benches for hundreds - or even thousands - of pounds.

People who’ve inherited property or are clearing houses for relatives are the most likely candidates to find an Aladdin’s cave of treasure in the garden, he says.

“The most common items that may be lying around are garden urns or statuary of the 20th century, the moulded urns and the moulded figurines and birdbaths which you think are just old and don’t have any value,” he says.

“Actually, there’s a very good second hand value for those items because dealers and interior designers like urns which look really weathered. They might only be 20 to 40-years-old, but there’s a definite market for antique-looking reproduction garden urns and other items.”

Such items may be made of concrete, otherwise known as reconstituted stone, and the ones fetching the most money have an 18th or 19th century feel to them, he says.

“I went into a shop the other day where there were four identical urns that were 2ft tall by 1ft wide with box bushes in them. They looked a million dollars and they were probably around £400 each.”

Birdbaths, weathervanes and other ephemera all have a value, he says.

“You could easily get £100 for a birdbath in an auction sale. It has to be weathered so that it doesn’t look new, which can take a few years.”

Coalbrookdale garden benches, which are made of highly ornate and Victorian-looking cast iron, are extremely sought-after items which can fetch between £3,000-£6,000. The 19th century benches are often stamped Coalbrookdale or C-B Dale Co, and the seat is probably made of timber slats.

"People may be sitting on a fortune because they just don't realise how expensive these benches are," says Jonty.

There is also a market for old garden tools, desired for their craftsmanship.

“Garden tools have a certain value,” he says.

“Don’t just throw them away. There will be somebody out there who wants them because they just love the feel of old wooden handles and cast metalware that’s not made to the same standard today.”

Spring and summer are the perfect times to sell garden memorabilia, Jonty adds. Dealers and salvage companies will buy many gardening items, while there are auction houses which deal specifically in high end garden statuary.

Even garden gnomes may fetch a price in the future, he adds. Like the William and Kate gnomes at this year’s RHS Chelsea Flower Show.

“Those will be worth an absolute fortune one day, simply because they were the first garden gnomes allowed in to the Chelsea Flower Show and due to the subject matter and the fact that she’s pregnant with the next in line to the throne, boy or girl.”

But what if you fancy acquiring some of these ornaments yourself? Dorset Reclamation at Bere Regis maintains an ever-changing collection of stone troughs, staddle-stones, obelisks, urns and old bath-tubs. Semley Reclamation near Shaftesbury is another amazing hunting ground, from Georgian and Victorian metal gates, to reclaimed blue lias paving; whereas ACE Reclamation at West Parley will be delighted to sell you anything from a cartwheel to a cast-iron urn.