Britain's plant life struck by two new deadly diseases that 'could be in every garden within 20 years'

The fears surround Phytophthora kernoviae and Phytophthora ramorum, or sudden oak death - relatives of tomato and potato blight which are spread by fungal spores in soil and water.

Initially the diseases infected ornamental and garden plants in the UK, but have spread to native countryside plants.
More here

be warned the link is from the Mail Online, try not to get distracted now...