Weed Potential

As a weed Pontic Rhododendron thrives in milder wet climatic conditions where it self propagates from seed or vegetatively and large establish standards soon migrate to adjoining land. The dense canopy restricts the light to the native seedlings limiting revegetation and reducing native animals.

This shrub produces horizontal branching that root wherever it touched the ground forming impenetrable thicket and can extend into wetland areas or along creek banks.

Control methodsfrom herbivores is restricted due to the poisonous foliage and buds. Livestock is also discouraged from eating the foliage and humans that consume the honey which is made from the plant becomes ill suffering from 'Mad Honey Disease'

The application of herbicide as a control method is limited due to the waxy surface of the leathery leaves an extensive root system developed by the plant.

Physical removal of the plant may be achieved using machinery and labour but can be a costly exercise. All the material should be removed offsite and destroyed. Under ideal conditions this shrub can grow to 10 m (30 ft) tall and cover an area of 100 square metres.

Sub-species
subsp.baeticum
This invasive vigorous shrub is similar to the species producing suckers and forming a compact rounded crown. It produces light purplish broad funnel shape flowers and is commonly cultivated in small gardens along borders or trimmed to form an informal hedge. This shrub is commonly used as a rootstock for other cultivars of Rhododendron but suckering growth needs to be monitored and removed.

Cultivar
'Variegatum'
This vigorous evergreen shrub is similar to the species with glossy green foliage with pale-yellow margins and produces pale to dark lilac-purple flowers during late spring. It prefers a dappled light position and is frost sensitive.