With the summer gardening season in full swing, homeowners across the UK are being cautioned to watch out for nine illegal plants that could result in substantial fines. Among these, Japanese Knotweed is a major concern, with more than 50,000 infestations recorded nationwide. Garden experts urge vigilance in identifying and eradicating these invasive species to avoid severe financial penalties.

Jack Sutcliffe, co-founder of Power Sheds, emphasized the importance of early detection: “Once you can identify the most common criminal plants, it’s important to prevent them from spreading as soon as possible. The easiest way to do this is by spraying them with chemicals, digging them out, or burning them.”

Here are the top criminal plants to watch for, along with the potential fines homeowners could face:

Japanese Knotweed

One of the most invasive plants, Japanese Knotweed, has bamboo-like stems and clusters of small white flowers. It can cause significant damage to property and infrastructure and is notoriously difficult to eradicate. Homeowners can face fines up to £34,000, with some lawsuits reaching as high as £200,000 for failing to disclose its presence during property sales.

Spear Thistle

Identified by its spiky leaves and purple flowers, the spear thistle is a noxious weed that can harm crops and other vegetation. Allowing it to grow can result in fines up to £2,500.

Common Ragwort

With its bright yellow flowers and feathery leaves, common ragwort is toxic to livestock. Fines for growing this illegal plant can reach up to £5,000.

Broad-Leaved Dock

Harmful to crops and vegetation, broad-leaved dock has broad leaves and spikes of small yellow flowers. It can spread easily and tolerates various weather conditions, leading to fines of up to £2,500.

Curled Dock

Similar to the broad-leaved dock, the curled dock has curly leaves and spikes of small yellow flowers. It is a resilient weed, with fines for its presence reaching up to £2,500.

Rhododendron Ponticum

This invasive plant, with evergreen leaves and large clusters of pink or purple flowers, competes aggressively for sunlight and is poisonous to other vegetation and wildlife. Fines can reach £5,000 for failing to control it.

Himalayan Balsam

Despite its attractive appearance, Himalayan Balsam is highly invasive, spreading quickly with its 800 seeds per plant. Fines can go up to £2,500.

Giant Hogweed

Harmful to humans, the chemicals in giant hogweed can cause severe skin wounds and permanent scars. Recognized by its large white flowers and towering height, fines for this plant can be as high as £5,000.

New Zealand Pigmyweed

This plant threatens other plants and aquatic environments with its invasive nature. Banned since 2014, the New Zealand Pigmyweed has small green leaves and clusters of tiny white flowers. Fines for allowing it to grow can reach up to £2,500.

Expert Advice Garden experts advise homeowners to seek professional help for removing these plants, especially Japanese Knotweed, to ensure complete eradication. Professional surveys, particularly for those selling property, can provide legal protection and prevent future disputes.