The Threat

Open borders, lack of resources, and the growing volume of imported plants have significantly accelerated the introduction and spread of various pests and diseases, including Ash Dieback and Oak Processionary Moth. These destructive invaders can have far-reaching consequences, affecting both urban and rural environments.

Currently, areas of Europe are infected with the bacterial disease Xylella fastidiosa which is known to attack a very wide range of species. Fortunately, there has been no detection of Xylella in the UK to date, however the risk of introduction is extremely high.

Perhaps the highest threat to a biosecurity breach comes from either individuals importing plant stock illegally (the recent DEFRA / Border Force campaign at ports of entry will hopefully have helped get the message out to members of the public), and from the man in a van type plant importers who may not always use the official plant biosecurity channels.

Insisting your tree supplier is Plant Healthy accredited will significantly reduce the risk of you inadvertently importing a serious plant pest or disease.

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The Consequences

All plants, especially trees are very important to the UK landscape and environment. Most people would agree with His Majesty King Charles III when he stated, “the future without trees is unthinkable” and “we must find a solution before it’s too late”.

Loss of the UK landscapeImported pests and diseases can kill or seriously affect a wide range of our tree species. The result could be a loss of important landscape and woodland trees, wildlife habitats, veteran, and ancient trees. All these trees have irreplaceable aesthetic value, and many are hundreds of years old. In urban areas we could lose the valuable ecosystem associated with trees, such as urban cooling, atmospheric particulate removal and surface water run off reduction.

CostThe financial impact that pests and disease cause are vast. There are significant costs for the removal of diseased trees on highways and public areas, which is necessary on health and safety grounds for local authorities and private landowners. There is an impact on the value of property where amenity trees are removed along with a potential negative impact on local recreation, regional tourism, and the visitor economy.

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Broadmead Hillier Tree Nursery Container Trees Growing in Row

Hillier Offering Reassurance

Our industry needs to do everything within its power to prevent further pest and diseases from entering the UK. That’s why here at Hillier Trees we:

  • Have a robust biosecurity policy which is regularly reviewed and updated.
  • Are holders of three key biosecurity / environmental accreditations.
  • Operate a zero-tolerance approach to biosecurity and will not import trees that are host to major pests and diseases from infected areas.


Our field grown trees are grown within our own fields for a minimum duration of 5 years, with certain specimens remaining under our care for as long as 25 years. The vast majority of our container grown stock will have originated from our own field production.

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