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<\/p>\nLavender is meant to help you sleep, but it keeps Nicola Spence awake at night. One of the many pests and diseases that worry England\u2019s chief plant health officer is Xylella fastidiosa. Lavender species are welcoming hosts for the bacteria.<\/p>\n
Xylella has not yet arrived in the UK but it has devastated olive groves in Italy and is spreading through Europe. It would be a serious threat to British fruit growers, and native oaks and elms, drying them out and eventually killing them, so the Royal Horticultural Society (RHS) has banned imported lavender and several other plant groups from the Chelsea Flower Show.<\/p>\n
\u201cIf we found Xylella at Chelsea, we\u2019d have to close the whole thing down,\u201d Spence says. It\u2019s not an idle threat. \u201cIn the build-up, we\u2019ve got two inspectors on site for two weeks checking everything with the RHS biosecurity team.\u201d She pauses. \u201cWe found some lavender last year. It was on the bottom of a trolley and someone had forgotten.\u201d The plants were tested and were disease-free, but the incident underlines the fragility of Britain\u2019s biosecurity.<\/p>\n
We meet on the frontline of the UK\u2019s biosecurity border, at Provender Nurseries in Kent. The nursery, a main grower and distributor of plants and trees to garden centres and landscapers, hosts an inspection point for the Animal and Plant Health Agency (Apha). Lorries come here directly after crossing the Channel and unload their plants inside a secure warehouse \u2013 even the ground is specially sealed \u2013 for officers to examine.<\/p>\n
Plant health and the environment are now considered to be integral to the UK\u2019s national security. It is not just making sure that Xylella does not infiltrate Britain\u2019s gardens. It is also ensuring that pests and funguses do not devastate crops, as Phytophthora infestans did in 1845, causing the Irish potato famine.<\/p>\n
The variety of threats is enormous. A stray lavender tray may seem banal, but in the US, a caver\u2019s boot was responsible for a disease that is devastating agriculture. The fungus Pseudogymnoascus destructans was accidentally imported about 20 years ago on the footwear of cavers returning from Ukraine to the US. It causes \u201cwhite-nose syndrome\u201d in several species of North American bat, wiping out at least 90% of some populations. Beetles, caterpillars and other crop pests that are usually eaten by the bats have thrived. In response, American farmers have increased pesticide use by more than 30% \u2013 a factor that may be linked to higher infant death rates.<\/p>\n
Even more concerning for UK security services is the possibility that a pathogen might be introduced deliberately. Last year, a Chinese couple were arrested after allegedly smuggling into the US a wheat-destroying fungus that was described by American attorney Jerome Gorgon Jr as a \u201cpotential agroterrorism weapon\u201d. In 1989, a disease broke out among cocoa plants in southern Bahia in Brazil that was reported to have been deliberately introduced to attack the plantation owners.<\/p>\n
\u201cThere is concern in the counterterrorism and homeland security network that plant products could be a risk,\u201d Spence says. \u201cWe haven\u2019t seen any plant pests and diseases used for deliberate release, but it\u2019s obviously something that we think about and are aware of.\u201d<\/p>\n
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Some households in the UK received mysterious packets of seeds in the post last year, sent from China. It was a resurgence of a phenomenon seen in 2020, when thousands of packets arrived unsolicited. Spence\u2019s team at Apha investigated and found they were harmless \u2013 they appeared to be part of a supposed \u201cbrushing scam\u201d, where vendors use the delivery as evidence of a sale so they can post fake reviews online \u2013 but \u201cthings like that can pop up from nowhere\u201d, she says. \u201cIf you were intentionally wanting to spread something, it\u2019s a pathway.\u201d<\/p>\n
Natural threats such as Xylella are more pressing concerns, and the types and variety of them are growing. Spence is the first chief plant health officer, appointed in 2014 after the post was created in response to the emergence of ash dieback, a fungal disease that is on its way to killing as many as 80% of Britain\u2019s ash trees.<\/p>\n
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