Seasonal · Canada
Frost protection for Canadian gardens
Late spring and early fall frosts are a classic Canadian plant killer—especially for containers and tender patio plants. A little forecasting goes a long way.
Know your risk window
Frost risk depends on your region and microclimate (city balconies can be milder than open yards). Watch overnight lows near 5°C and below, especially under clear skies and calm wind.
GardenGreen’s atmosphere card can flag frost conditions when location weather is available—use that as a heads-up, not a substitute for local forecasts.
What to do before a frost night
- Move containers against the house, into a garage, or indoors if tender.
- Cover in-ground plants with frost cloth, old sheets, or row cover before dusk; remove in the morning for light.
- Water soil earlier in the day (moist soil can buffer temperature better than bone-dry soil—avoid soaking leaves at night).
- Prioritize tropicals (citrus, basil, tomatoes, many houseplants summering outside).
Plants often grown outdoors in our library
Peace Lily
Spathiphyllum wallisii
Lavender
Lavandula angustifolia
Japanese Maple
Acer palmatum
Rose
Rosa spp.
Bonsai Pine
Pinus thunbergii
Phalaenopsis Orchid
Phalaenopsis spp.
Basil
Ocimum basilicum
Mint
Mentha spp.
Tomato
Solanum lycopersicum
Anthurium
Anthurium andraeanum
Olive Tree
Olea europaea
Meyer Lemon
Citrus × meyeri
After a frost
Wait to prune until you see what recovers. Blackened soft tissue can be removed once damage is clear. Move survivors to brighter protected spots and resume careful watering.
FAQ
At what temperature should I protect plants?
Many tender plants need protection at or below about 5°C, especially if the low lasts for hours. Hardier shrubs tolerate more cold once established.
Can I leave houseplants outside in Canadian summer?
Yes in warm months if light is appropriate—but bring them in before nights cool in late summer/early fall, and harden them to outdoor sun gradually.
Do frost blankets really work?
Yes when draped to the ground before dusk and secured. Plastic touching leaves can worsen damage; use fabric covers instead.