As anyone who has got carried away at the garden centre will know, making your garden look great for the summer doesn't come cheap. But whether it's patio furniture or just keeping a few plants, money spent on keeping your garden looking good can have a positive impact on the value of your house. According to Sainsbury's Bank Home Insurance, 1.25million home-owners plan to spend more than £1,000 on their gardens this summer.

Robert O'May, home insurance manager at Sainsbury's Bank, said: "People are not only taking greater pride in their gardens, they also realise the value they can add to their homes. This means that people are spending thousands on improving their gardens."

But for many people, spending a small fortune on the garden could be money down the drain, as lack of security often turns our back gardens into rich-pickings for theives. "Sadly, it's sometimes not just a few plants or garden chairs stolen," Mr O'May said: "Victims can literally have thousands of pounds stolen from their gardens. Indeed an entire lawn was recently reported or stolen, as was a 6ft by 4ft pond with the fish it contained."

Clearly, it is difficult to padlock your petunias, chain down your lawn or electronically tag your goldfish, but it is possible to increase security so that theives are less likely to see your garden as an easy target. As with home security, deterrents are important in reducing oppurtunistic crime, so planting prickly shrubs such as pyracantha, holly or some varieties of roses can be an attractive and spiky barrier on top of fences and walls. But because these take a while to become established, it can also be a good idea to nail a flimsy garden trellis to the top of fences to make it too unstable for would-be burglars to climb over.

Even if your garden is well protected by a fence, security for sheds and garages can often be overlooked. Crammed with expensive items like lawnmowers, power tools and bikes, the humble shed can be a treasure trove for theives. Ladders, hammers and spades can also be used by burglars to break into your house so it is vital to keep them under lock and key. If you have a burglar alarm on your house, find out if it can be extended to cover any out-buildings and fit strong locks to keep everything secure.

If you have a driveway, consider laying gravel as it will act as an early warning system if someone is wandering around without your knowledge. Security lighting will also help to alert you to anyone approaching the house or garden and a good old-fashioned neighbourhood watch scheme can be a great deterrent to theives.

Garden ornaments, statues, planters and furniture are amongst the most common items stolen from gardens and are also some of the most expensive to replace. Cementing your gnomes to the rockery may seem a bit drastic, but where possible try and make it difficult for theives to lift or remove items by weighing them down with bricks.