The firm discovered that 17 per cent of respondents saw them as vital to their gardens, although outdoor furniture was regarded as the most sought after item in the poll.
More than half outlined sheds as their favoured garden feature, while 28 per cent have been nurturing vegetable patches.
According to the survey, a total of £5.2 billion has been spent on gardening in the UK in the past 12 months, which has led to many houses rising in value.
“Britons are seeking to maximise the value of their entire property by looking beyond interior home improvements and boosting the value of their property by improving the garden area,” commented director of Santander Insurance Colin Greenhill.
However, the results of the research conflict with the findings of a similar study recently conducted by rival HSBC, which found that UK gardeners actually spend up to £7.7 billion on the upkeep of their outside areas each year.