The Tree of Hell and Others

Invasive non-native species

Invasive Species Week usually takes place in May with campaigns around the UK looking to raise awareness of invasive non-native species and tackle the issues on the ground with volunteer groups. Unfortunately, Covid-19 and lockdown means it is postponed until later in the year.

However, many forestry sites are still active and it is at this time of year we start to see the emergence of non-native invasive plant species which not only harm the environment and wildlife, but also can be harmful to our workforce.

An example of such harm was reported to us in an incident where a contractor moving logs following felling suffered a serious skin reaction to sap from Tree of Heaven.

The Tree of Heaven, or as some prefer to call it, the Tree of Hell, is widely planted in parks and urban areas. In South East England, because of its invasive nature, it escapes and spreads. It is harmful when the sap is in contact with the skin and then exposed to ultra-violet light. Affected areas will redden and in most cases be followed by blisters that can be painful for a couple of days. In some cases, the blisters will lead to a brownish pigmentation that can last for years. Blistering and burning in this way is inevitable if skin comes into contact with sap from broken or cut stems or leaves.

Note also that certain species, Himalayan Balsam, for example, can cause some people to suffer an allergic reaction to its pollen.

Examples of other plants known to be harmful are given in our Toolbox Talk: Harmful and Phyto-Photo-Dermatitis Causing Plants (TT/06)

What are Invasive Non-Native Plants?

Invasive non-native plants are species which have been brought to the UK and spread causing damage to the environment, the economy, our health and the way we live.

Most non-native plants are not a problem, but around 10-15 % have become invasive. There has been a dramatic increase in numbers over recent years with ten new species becoming established in 2017.

Shown below are some non-native invasive plants which can also be harmful to workers on site.

Avoiding spread

Invasive non-native species are easily spread. For example, Japanese knotweed spreads rapidly not only through its root system but because any fragment of its stem or root will grow to form a new plant. This makes it very difficult to get rid of.

Legal responsibilities

Non-native species legislation in England, Scotland and Wales prohibit the spread of non-native species and require landowners to manage and dispose of non-native species correctly in order to prevent spread.

Be Aware and Report: All work sites should be assessed for significant health, safety and environmental hazards and constraints. If non-native invasive species and noxious or harmful plants are present they must be identified on the Site Map, cordoned off if appropriate, and their presence briefed to workers on site.

Always be alert on site to previously unidentified plants which you think may be harmful:

The following Website provides some useful identification sheets for all non-native species: GB Non-Native Species Secretariat Website

Above; Himalayan Balsam, Giant Hogweed,Tree of Heaven