Week 5 · Plants

Know your frost line

Edible Landscapes

Frost tolerance is local. A citrus that survives Auckland frost may die in Christchurch open ground; a feijoa in Invercargill needs shelter while the same species thrives exposed in Whangārei. Use your own thermometer and historical notes — not generic plant labels alone.

Protection options

  1. Site selection first

    North wall radiates heat; cold air drains to hollows — plant up-slope where possible.

  2. Microclimates for pots

    Move containers under eaves or into glasshouse — roots freeze in pots before in-ground plants.

  3. Frost cloth overnight

    Remove or vent during day to avoid overheating and fungal issues.

  4. Delay hard pruning

    Wait until frost risk drops — fresh cuts are frost entry points.

Glasshouse hygiene

Vent on clear days even in winter; stagnant humid houses breed disease on citrus leaves.

Realistic species

Subtropical ambition in cold districts belongs in pots with winter plan — not grief each July.