Sainsbury's Home Insurance is warning gardeners and home-owners to be wary of a link between tree-planting and subsidence.

"It's great news that so many of us are good-intentioned when it comes to planting trees, but it's important that we don't put our properties at unnecessary risk of subsidence,” said Neil Laird, Sainsbury's Home Insurance manager. “Our advice is to do your homework before putting spade to soil."

The British supermarket giant released information on its corporate site, indicating that close to 9.7 million plan to plant trees in their garden this year, and may be completely unaware of the risk of subsidence. The key, according to the report, is not only pick an appropriate kind of tree for the size of the garden, but also to ensure that trees are planted an adequate distance away from any building or property. The report indicated further, as an example, that a maple tree should be planted at least 9 to 12 metres away from one’s home or property.

The corporate site provided analysis of industry data, suggesting that insurance providers in the UK may have paid out an average of £710,000 a day for subsidence claims over the past five years. Sainsbury’s Home Insurance alone has attributed 12% of the money they’ve paid out to subsidence and other vegetation. Evidence suggests that trees such as leylandii and willows are more likely to cause subsidence.

"Planting trees is not only a commendable act in today's environmental climate; a well thought out garden can also add significant value to your property,” adds Laird. “However, people intending to plant a tree in their garden this year should be very careful about which type of tree they plant and how far away from the property they plant it. For example, our research shows that over 1.1 million people intend to plant a willow tree, which is a cause for concern given that this type of tree shouldn’t really be planted any closer than 18 metres away from your property to avoid risk of subsidence damage.”

Information provided by Sainsbury’s Home Insurance indicates that Holly is ideal for a smaller garden, as are Laurel or Magnolia trees. These reportedly can be planted to within 5m of property, and are known as low-water demand trees.  Other advice from the report includes checking the home survey for information on previous mining activity when homeowners purchase a property, performing a survey on the drainage of a newly-acquired property, performing regular checks for blocked or leaking drains, blocked gutters, and cracked pipes, and ensuring that trees and shrubs are routinely pruned. The home insurance company further stresses that if property owners suspect that their property is suffering from subsidence, their insurer should be notified as soon as possible, “as the sooner the problem is diagnosed, the sooner and easier it will be to repair.”

According to the home insurance company’s research, the most popular tree to be planted in the UK this year is the apple or pear tree, (with more than one in 10 of residents intending to plant at least one), followed closely by the cherry tree (7%) and the plum tree (4%).