For any viticulturist, grape grower, vineyard, or winery, choosing a vineyard trellis post system can be just as important as choosing high quality components or the right equipment to make your best product. And as with any product or equipment, we all know that cheap doesn’t always mean the best.
For any business installing or replacing trellis, we recommend a vineyard post comparison of durability, cost efficiencies and overall environmental impact of different systems to make sure you choose a system with the best long-term benefits.
So, when it comes to wood versus steel versus alternative options, here are a few details you should consider.
Wooden posts have previously been the most common type of trellis post due to widespread availability and easy installation. However, most wooden posts are chemically treated timber which is cheaper to install but isn’t environmentally friendly, organic, and is associated with much higher end of life costs.
Traditionally the most popular style of timber post, Copper Chrome Arsenate or CCA, are treated wood with high breakage rates. CCA posts can’t be burned legally and are notoriously difficult to dispose of, which means large piles of broken posts out the back of vineyards all around Australia.
Creosote posts which are mostly available in South Australia may have lower breakage rates but still have a high cost of disposal and are incredibly toxic, often leading to chemical burns. The best wood-only option is a hardwood system, which is recyclable and has a longer life span, but is still designed through unsustainable practices.
There are several options when it comes to steel post shapes, from picket-style to tubular. Steel options have lower breakage rates and are more sustainable than their wooden counterparts, as they can be recycled after use. However, there is the risk that your steel posts will rust, while some picket-style posts can bend easily under mechanical harvesting.
A big decider when it comes to using steel posts are the fasteners required. Steel posts can’t be nailed or screwed into, meaning you’ll have to use custom fasteners to connect your system. Which can add up when it comes to your overall budget.
As viticulture innovates for the future, there are many different options to consider that can lead to a financially and environmentally sustainable decision.
The approach of using concrete may have its benefits of sustainability and a long lifetime, but they also require custom fasteners, custom installation and lifting equipment. This means at the end of the day they have higher set up costs and a high cost over their lifetime. Other options like mixtures of composite and solid plastic posts are easy to handle, recyclable, have a long lifespan, and can be used with standard fasteners. However, any post made of a solid or hollow polymer will be susceptible to what is called the ‘sunflower effect’. This means they can bow and bend to the sun, particularly for posts that are more than 1.2 metres out of the ground.
Our favoured product is a plastic and wooden post hybrid produced right here at Woodshield. A polymer coated, chemical free timber post, it has the strength and rigidity of a wooden post combined with the protective properties, toughness, and lifespan of polyethylene. Being a hybrid, the posts aren’t susceptible to the sunflower effect and have a longer lifespan, can be recycled, and can be easily installed with regular fasteners. They’re also certified for organic or eco growers.
So, what is best for me?
At the end of the day, we recommend that all buyers do their own research prior to purchase. But for us, we’ve put the data from our research online and within the industry to give you our individual opinion and a visual guide to different trellis post systems so you can make up your own mind.