How to grow Sweet Chestnut in New Zealand
Sweet chestnut (Castanea sativa) is a large, long-lived deciduous tree that drops spiny burrs full of glossy brown nuts in autumn. It suits cooler districts with free-draining, neutral to acid soil, and is reasonably drought hardy once established. It is a tree for a big section or a lifestyle block: it spreads wide, and you need two compatible trees for a good crop.
📖 Our full guide: How to Grow Chestnuts in New Zealand
At a glance
When to plant by region
| Region | When to plant | Regional note |
|---|---|---|
| Northland | June to August | |
| Auckland | June to August | |
| Waikato & Bay of Plenty | June to August | |
| Central North Island | June to August | |
| Wellington & Lower North Island | June to August | |
| Nelson & Marlborough | June to August | |
| Canterbury | June to August | |
| Otago & Southland | June to August | |
| Central Otago | June to August |
Where to plant
Plant chestnuts in full sun in deep, free-draining soil that is neutral to acid. They do not tolerate wet feet, and waterlogged soil invites ink disease, a root rot caused by Phytophthora. Allow plenty of room, as mature trees spread wide and cast heavy shade.
- All regions: our calendar shows chestnuts can be planted from June to August throughout New Zealand. They do best in cooler districts with acid soil and are reasonably drought hardy once established.
Choosing a variety
Grafted named varieties crop far sooner and more reliably than seedlings, which may take 20 years or more and vary in nut quality. Chestnut flowers carry both male and female parts, but trees crop much better with a second, compatible variety nearby, so plant two. Ask a specialist nursery which varieties pollinate each other.
How to plant
- Dig a hole twice as wide as the root ball and to the same depth in free-draining soil. Do not add lime.
- Spread the roots of bare-root trees over a mound in the hole, plant at the same depth as before and backfill.
- Water in well and mulch, keeping the mulch clear of the trunk.
- Protect young trees with a tree guard where possums, rabbits or stock are about.
Watering and feeding
Water young trees through dry summers for the first few years. Established trees are reasonably drought hardy, but regular water in late summer helps the nuts fill. Avoid waterlogging.
Pruning and care through the year
- Prune young trees to form a strong framework, then prune only to remove dead or crossing branches.
- Keep the area under the tree mown or mulched so fallen nuts are easy to find.
Harvesting
Chestnuts ripen from February to April. The spiny burrs split and drop the nuts, which are ready when they fall. Gather them every day or two, wearing thick gloves, before they dry out or are taken by animals.
Fresh nuts keep a few weeks chilled. They also dry or freeze well.
Using it
Roast chestnuts after scoring the shell with a cross so they do not burst, or boil them and peel off the shell and inner skin. Use them in stuffings, soups and desserts, or dry and grind them into chestnut flour.
Pests and diseases
In New Zealand, possums and the soil around the roots cause most problems.
Pests to watch for
- Possums Bark chewed and young shoots stripped. Use tree guards on young trees.
- Grass grub Roots of young trees chewed in pasture, with yellowing and poor growth.
Diseases to watch for
- Root rot Ink disease: wilting, yellowing and dieback, with dark, inky staining at the base of the trunk, in wet soil. Plant in free-draining ground.
- Chestnut blight Sunken orange-brown cankers on the bark that girdle branches, with leaves wilting above them. New Zealand is free of chestnut blight, so report any suspected case to MPI on 0800 80 99 66.
Common questions
Can I grow chestnuts in New Zealand?
Yes, they grow in most regions and do best in cooler districts with free-draining, acid soil. They need lots of room.
Do I need two chestnut trees?
For a good crop, yes. Plant two compatible varieties close enough for pollen to move between them.
How long until a chestnut tree produces?
A grafted tree may start within about five years. A tree grown from seed can take 20 years or more.
When are chestnuts ready to harvest?
From February to April, when the burrs split and the nuts fall. Collect them every day or two with thick gloves.
How do I store chestnuts?
Fresh nuts keep a few weeks in the fridge. They can also be dried or frozen.
Sources we checked: Wikipedia: Castanea sativa; NZ Tree Crops Association: Chestnut.