Whilst not declared an environmental weed in this Shire (Yet!), this plant is certainly an undesirable, nuisance plant in the Southern Highlands and many other areas. We are not alone in this opinion. Earlier this year at a Wingecarribee Council meeting, many concerns about the extensive use of this plant in Southern Highland’s landscapes were raised. Some of the comments made, as per this article by Southern Highlands News, were that these plants are ‘nothing more than “view-theft”‘ and that there is a lack of understanding about their growth habits and the lack of habitat they provide.
The loss of rural vistas is not the only problem with the use of Leylandii in our landscape. These plants are extremely flammable and the extensive use of these plants in our bushfire-prone Shire is a huge risk to lives and property.
The impact of these hedges that can reach over 40m in height in suburban areas creates huge problems with solar and moisture deprivation along with disputes between neighbours. Most people are unaware of the potential mature height of these trees, as current plant label requirements only require the display of heights at 10 years of maturity. Unless pruned regularly, these plants become expensive and labour-intensive to maintain and so quickly get out of hand.
As time goes by many people lose the passion or become budget sensitive when it comes to pruning these trees. When left unpruned they loose their lower foliage with the resulting loss of functional screening ability. They also suffer from a disease called canker which readily infects trees that are under stress and frequently pruned. Leylandii Hedges not only end up looking ugly, but also create many disputes between neighbours regarding solar access and encroachment over boundaries.
They are widely promoted by the uneducated or inexperienced in the horticultural profession as a quick growing screening plant in rural and urban areas. They fulfil this role when young and maintained regularly, but soon become an expensive nightmare as time goes by. Many native plants are far quicker in establishing windbreaks and screens if given the same horticultural attention.
Leylandii as Windbreaks
Windbreaks created with Leylandii or similar species obstruct the wind which then creates turbulence. Leyland achieve very effective wind protection but for only a relatively short distance on the leeward side of the windbreak. Once out of this minimal protected zone, wind speeds and turbulence increase with intensified risk of damage to crops, gardens or structures. Unless they are pruned regularly within 10-15 years they begin to loose their lower foliage making them ineffective as windbreaks and screens. Leylandii may be effective as a hedge if clipped but would be determined as completely unsatisfactory as a windbreak when the science is considered.
Below are some examples of windbreaks utilising native plants established by Wariapendi in the Southern Highlands which can be used as a quicker and more sustainable alternative to Leylandii pines. They also add to our local ecology by providing excellent habitat for our wonderful and diverse range of birds.