Ten Tips for Mulching on a Vineyard

Mulching is a common practice in vineyards across the Mornington Peninsula, offering benefits such as improved soil health, weed suppression, and moisture retention. We’ve pulled together best practice guidance and case studies from across Australia and beyond, to support vineyard managers in deciding what works best for them.

1. Select Mulch Based on Vineyard Conditions

Different mulch types—like straw, composted green waste, or wood chips offer different benefits. Your choice will depend on your block layout, soil profile, and harvest approach. The Australian Wine Research Institute (AWRI) outlines the strengths and risks of each option.

2. Apply Straw Mulch Appropriately

Straw mulch is typically applied at around 11 tonnes per hectare and needs reapplication every three to four years. It’s important to avoid material that may contain weed seeds or be contaminated with herbicide. See AWRI’s practical mulch guide here.

3. Turn Cover Crops into Living Mulch

Managing cover crops by slashing them in-season can provide green mulch that improves soil structure and feeds microbial activity. A Western Australian case study showed that cover crops also assist in frost mitigation and biodiversity.

4. Compost for Long-Term Soil Health

Well-composted mulch offers longer-lasting benefits, especially when soil moisture retention and nutrient cycling are a priority. SoilHub’s vineyard compost trials highlight performance differences between fresh and aged materials.

5. Avoid Over-Mulching

Too much mulch can restrict oxygen and water from reaching vine roots. A balanced layer, generally around 5–10 cm is ideal. This allows water to filter through while protecting the soil. Over-mulching also increases pest risk and may reduce nutrient availability.

6. Monitor for Biosecurity Risks

On the Mornington Peninsula, vineyards must manage Phylloxera risk when moving organic materials. Mulching on-site significantly lowers contamination risk. You can read the PEZ guidelines here.

7. Consider Undervine Applications

Many vineyards opt to apply mulch only in undervine zones. This limits costs, controls weeds, and improves vine access. This is also common in drip-irrigated blocks where interrow management is handled separately.

8. Balance Mulch Type with Machinery Access

Straw mulch can reduce vineyard trafficability during winter. Wood chips and composts tend to settle more, but may require specialised spreading equipment. Choose material based on how frequently vehicles or harvesters move through your rows.

9. Use Local & Well-Composted Material

Locally sourced mulch minimises transport costs and reduces the risk of introducing foreign weed species or pests. Wherever possible, use material that’s been composted to standards that ensure consistent breakdown and safe microbial activity.

10. Reflect on Cost vs. Benefit

Many vineyards have found that the upfront investment in mulching pays off through reduced irrigation, better fruit quality, and improved soil health. The team at Sustainable Winegrowing Australia shares several real-world examples.