Scientific name: Impatiens glandulifera

Also known as: Police Helmets, Indian balsam, Jac y Neidiwr

Key Facts • Himalayan balsam is an annual plant with bright purple-pink

flowers.

• It is listed under schedule 9 of the Wildlife and Countryside Act 1981 – it is an offence to plant or cause this species to grow in the wild.

• It was introduced as an ornamental plant in the early nineteenth century.

• It is found throughout Wales, and is most commonly found along waterways and in damp places.

• Mature seed pods explode when ripe, spreading seeds up to 7m from the parent plants. Seeds are also transported via water courses.

Description

Himalayan balsam is an annual plant (it completes its lifecycle within one year), which grows to 2m tall with rough, reddish stems, shiny oval leaves about 15cm long with a red vein, and bright purple-pink flowers from June-September. It produces seedpods which explode when ripe spreading the seeds up to 7m. It tends to form dense stands of plants that smother out other plants.

Public information on invasive species in Wales

Himalayan balsam

Lifecycle Seedlings start to emerge in March and April with the first flowers appearing in June. It produces seedpods from July with ripe seeds being distributed from then until October, when the plant dies having produced up to 800 seeds.

Seedlings emergeFoliage growth

FloweringSeeds shed

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Identification

Leaves – Slender, oval and shiny about 15cm long with a red vein running up the middle. Leaves are arranged on the stem either opposite or in bunches of three. Leaf margins are finely serrated with 18 to 50 teeth on either side.

Stem – Hollow, brittle, smooth, reddish translucent stem. 0.5 to 5cm in diameter. Usually a single stem but sometimes branched.

Flowers – Flowers are either pink or purple-pink, three petals and trumpet shaped with a sharp bent spur at the back. There are three to twelve flowers per plant which are two to four cm long. Flowers are located at the top of the plant.

Seedpod – The plant sets seed from mid-July onwards. The seedpods are 2.5cm long and hang down from red stalks. Seed capsules explode at the slightest touch when ripe.

Lookalikes There are three other balsam plants that are similar but have important differences. They all have smaller leaves (10cm) and are shorter in height (0.5-1m) but the main difference is their flower colour:

• Orange balsam (Impatiens capensis) has red spotted orange flowers;

• Touch-me-not balsam (Impatiens noli-tangere) has yellow flowers; and,

• Small balsam (Impatiens parviflora) has small pale yellow flowers.

A plant that is very similar is Great Willowherb (Epilobium hirsutum) which is as tall as Himalayan balsam and has pink flowers. The important differences are the Great Willowherb leaves are round (rather than oval), the stems which are stiffer and hairy, the flowers which have 4 petals and the seedpods are long and thin. Great Willowherb spreads by underground roots (rhizomes). When you dig up the plants you will see the plants are linked together by the roots. Himalayan balsam plants each have an individual root ball.

Management Control Options There are a number of control measures for Himalayan balsam depending on the size of the infestation, the equipment available and the time of year. The aim is to kill existing plants and prevent seed return so any control measures need to take place before the seedpods start to ripen in July. Seed can survive in the soil for up to 3 years so annual treatment will be required, and monitoring for a further 2 years to ensure eradication.

Where it is found in WalesHimalayan balsam is found across Wales most commonly along waterways and in damp places.

It spreads through local seed dispersal. Each plant can produce up to 800 seeds per year. Seeds are dispersed by exploding seedpods which can scatter seeds approximately 7m from the plant. However, given their common habitat near waterways, the seeds are also spread by water especially when land is flooded which can lead to new infestations along river banks.

Legislation and responsibilitiesHimalayan balsam is listed under schedule 9 of the Wildlife and Countryside Act 1981. It is an offence to plant this species or to cause it to grow in the wild. There is no obligation to eradicate this species from land or to report its presence to anyone. However, if this species spreads to the wild or to a neighbour’s property then landowners/managers could be liable.

Why is it a concern?Himalayan balsam can quickly form very dense stands which smother all native vegetation including grass and other plants, reducing the biodiversity of the location. When the plant dies back in the winter it leaves bare ground which is more susceptible to erosion which can lead to large sections of river bank being eroded. The flowers of Himalayan balsam are attractive to bees which has the potential to bias bees to collect nectar from the balsam rather than from native species, thus reducing native plant pollination.

Orange balsam Small balsam

Touch-me-not balsam

References and further sources of information Find the Wildlife and Countryside Act 1981 on the Legislation.gov.uk website.

Find the Environmental Protection Act 1990 on the Legislation.gov.uk website.

Centre for Ecology & Hydrology (2004) Information sheet 3: Himalayan balsam. Available from: http://www.nonnativespecies.org//downloadDocument.cfm?id=1055

GB Non-native Species Secretariat website. https://secure.fera.defra.gov.uk/nonnativespecies/home/index.cfm

If the Himalayan balsam is near a water course, permission for treatment with herbicides must be given by Natural Resources Wales prior to application.

If the Himalayan balsam is on a designated site such as a Site of Special Scientific Interest (SSSI), Special Protection Area (SPA) or Special Area of Conservation (SAC) then written permission will be required before treatment from Natural Resources Wales.

This information leaflet has been produced for the Welsh Government

by ADAS UK Ltd. www.adas.uk

Welsh GovernmentNatural Environment and Agriculture

TeamRhodfa Padarn

AberystwythSY23 3UR

planthealthbiotech@wales.gsi.gov.uk

Amenity Assured Compliant Contractors More information from BASIS: www.basis-reg.co.uk 01335 343945

National Association of Agricultural and Amenity Contractors have a list of contractors in the Amenity sector

It may be appropriate to employ a specialist contractor for assessing the best method of control and to apply any pesticides. Good contractors will have the following:

• A BASIS certified practitioner with knowledge of control of invasive weed control to recommend appropriate chemical control options.

• A spray operator who holds the appropriate National Proficiency Tests Council (NPTC) certification for herbicide use or works under the direct supervision of a certificate holder.

• If sprays are to be applied in or near water, the person carrying out or supervising the spraying must have the appropriate aquatic part of the qualification.

Lists and details of contractors can be found through the sites below.

Selecting a contractor

Hand pullingSmall infestations can be easily controlled by hand pulling plants. The plants have a shallow root system and should be firmly pulled out holding the base of the stem. Care needs to be taken to avoid snapping the stem above the first node as plants can regrow. Plants are pulled in the spring or early summer (April/May) before flowering (June/July). The site is usually revisited to pull any smaller plants that were missed or any late germinators.Pulled plants can be left on-site to decompose in an open area or put in a compost bin. It is best to avoid taking the plants off site for disposal or putting them in the recycling bin in case there is contamination by seeds.Mowing and cuttingMowing and cutting are less labour intensive and is usually used for large infestations.Cutting using a scythe, machete, flail or strimmer is usually carried out before flowering in June. Plants are cut close to ground level, below the lowest node, to prevent regrowth. A repeat cut may be needed and the site revisited after 2 weeks to check for regrowth.Cut stems can be left on-site to decompose in an open area. It is best to avoid taking the plants off-site for disposal or putting them in the recycling bin in case there is contamination by seeds.Herbicide controlHerbicides can be applied to the plant foliage in the spring before flowering. Glyphosate is usually used however, it is non-selective so will kill all other vegetation on the site. After treatmentAfter removing, it is important to re-establish native species of plants. This will help to achieve control, reduce soil erosion and provide competition for Himalayan balsam seedlings. Control of native cover in following years may necessitate the re-establishment of this cover as the use of glyphosate will kill all vegetation. Individual targeting of plants will minimise death of native vegetation.

Management Control Options - continued