When to Plant Walnut in Canberra — Cold / Highland Guide

Walnut

Photo: Wikimedia Commons

Large deciduous nut tree that needs cold winters (500-1000+ chill hours) and warm dry summers. One of the best nut trees for cool-temperate and cold-highland Australia. Beautiful timber tree and shade tree. Important: walnut trees produce juglone, a chemical toxic to many plants grown nearby (allelopathy). Long-lived (100+ years). English walnut (J. regia) is the eating nut; Black walnut (J. nigra) used as rootstock and for timber.

How to Grow Walnut in Cold / Highland Australia

When to Plant

Plant bare root August.

Soil
Deep, fertile, well-drained. Walnuts have deep tap roots and need minimum 2m soil depth. Reasonably tolerant of clay but must not be waterlogged.
pH Range
6.0-7.5
Sunlight
Full sun.

Companion plants: Grass (tolerant of juglone)

Avoid planting near: Tomato, potato, pepper, eggplant (juglone sensitive), Apple trees (some juglone sensitivity), Azalea, rhododendron (juglone sensitive), Any plant within root zone that is juglone-sensitive

Cold / Highland Growing Tips for Walnut

Recommended Varieties

  • Franquette (cold-hardy, late-leafing)
  • Chandler
  • Howard

Key Challenges

  • Late spring frost on new growth
  • Short growing season for nut fill

Pro Tips

  • Good zone for cold-hardy varieties.
  • Franquette leafs out late, avoiding spring frost.
  • Orange NSW, Canberra area are viable.

Harvesting Walnut

When ready: Green husk cracks and separates from shell. Nuts begin to fall from tree. Shake branches to accelerate harvest.

How to harvest: Collect fallen nuts. Remove any remaining husk (stains hands - wear gloves). Dry in single layer in shade for 2-3 weeks until shell interior walls are dry.

Get the Full Interactive Guide

Track your garden, get real-time pest alerts, and plan around your zone's weather.

Open the planting dashboard Join Garden Buddy