Temperature Management
Bonsai Temperature Management Reference
Because bonsai roots live in shallow containers above ground, they lack the ground insulation of landscape trees. Reference these threshold tables to protect your trees from freezing winter temperatures and intense summer root baking.
1. Bonsai Cold Limits / Indoor Bring-In Thresholds
Ordered from highest threshold (least frost tolerant) to lowest threshold (most cold hardy). Tropical and sub-tropical trees must enter warm living spaces or greenhouses, while temperate species require cold dormancy (32°F–45°F) in an unheated garage or shed.
| Tree Species | Cold Limit / Bring-In Temp |
|---|---|
| Habanero Pepper (Capsicum chinense) | 55°F (13°C) |
| Cayenne Pepper (Capsicum annuum) | 50°F (10°C) |
| Kaffir Lime | 50°F (10°C) |
| Bougainvillea | 45°F (7°C) |
| Ficus retusa | 45°F (7°C) |
| Dwarf Jade (Portulacaria afra) | 40°F (4°C) |
| Lantana | 40°F (4°C) |
| White Lead Tree (Leucaena leucocephala) | 40°F (4°C) |
| Australian Willow (Geijera parviflora) | 35°F (2°C) |
| Sweet Olive (Osmanthus fragrans) | 35°F (2°C) |
| Lemon Cypress | 32°F (0°C) |
| Pineapple Guava (Acca sellowiana) | 32°F (0°C) |
| Arbequina Olive | 30°F (-1°C) |
| Glossy Ligustrum | 25°F (-4°C) |
| Crepe Myrtle | 20°F (-7°C) |
| Japanese Green Maple (Acer palmatum) | 20°F (-7°C) |
| Japanese Red Maple (Acer palmatum) | 20°F (-7°C) |
| Dragon Willow (Salix matsudana ‘Tortuosa’) | 20°F (-7°C) |
| Judas Tree (Cercis siliquastrum) | 20°F (-7°C) |
| Chinese Elm (Ulmus parvifolia) | 20°F (-7°C) |
| Rose of Sharon Hibiscus (Hibiscus syriacus) | 15°F (-9°C) |
| Japanese Okame Cherry | 15°F (-9°C) |
| Japanese Kwanzan Cherry | 15°F (-9°C) |
| Japanese Boxwood | 15°F (-9°C) |
| Japanese Garden Juniper (J. procumbens ‘Nana’) | 10°F (-12°C) |
| Bald Cypress | 10°F (-12°C) |
| Japanese Black Pine | 10°F (-12°C) |
| American Blue Moon Wisteria | 5°F (-15°C) |
| Chinese Wisteria | 5°F (-15°C) |
| Weeping Willow (Salix babylonica) | 0°F (-18°C) |