How much cold can my houseplants handle?

 

Start with the basics: What region did your plant call "home"?

 

• Plants native to the subtropics are in danger below 40 degrees F and pretty certainly going to be killed at 32 degrees F.
• Plants native to the tropics are often damaged below 50 degrees F and perish at about 40 degrees F.
• A few moments of cold is often not enough to kill tender plants but the longer they remain cold, the more likely they will be damaged.
• For tender plants in the ground, roots and stems bases may escape injury even if the plant's top is killed back, since soil is a good insulator. So some plants that lose their tops to cold may regenerate later from a still-live base.

Some common houseplants' origins and lowest safe temperature

May die below 55° F:

• Belgian evergreen (Dracaena sanderiana), W. Africa, 50 degrees
• Corn plant (Dracaena fragrans), tropical Africa, 55 degrees
• Dragon tree (Dracaena marginata), Madagascar, 55 degrees
• Fiddleleaf fig (Ficus lyrata), W. tropical Africa, 60 degrees
• Ficus tree (Ficus benjamina), India, 50-55 degrees
• Rubber plant (Ficus elastica), tropical Asia, 55 degrees

 

May die below 50° F:

• Amaryllis (Hippeastrum  hybrids), Central America, and Brazil to Argentina, 55° F (leaf), 40° F (bulb)
• Coleus (Solenstemon spp.) tropical Africa & Asia, 50°F
• Hibiscus (H. rosa-sinensis), tropical Asia, with some hybrids from tropical Africa and Hawaii, 50° F
• Jasmine vine (Jasminum polyanthum), tropical China, 50° F
• Swiss cheese plant/Mexican breadfruit (Monstera deliciosa), tropical Mexico, 50° F

 

May die below 40° F:

• Geranium (Pelargonium spp.), S. Africa, 40-45° F
• Jade tree (Crassula argentea), S. Africa, 40° 

 

Hardier than you thought:

• Bay tree (Laurus nobilis), Mediterranean, 10-15° F
• Christmas/Easter/Thanksgiving cactus (Schlumbergera hybrids), Brazil, 35° F (but flowering temperature is 55° F)
• Rosemary (Rosmarinus officinalis), Portugal, NW Spain, 0° F

One last note:

We've inadvertently pushed some of our own plants past these lowest safe temperatures. That they survived was sometimes just luck. For instance many Dracaena and tropical Hibiscus species can survive an additional ten degrees of cold, to 45° F, Pelargonium plants may approach freezing, and jade tree can survive to 25° F, if those plants were also being kept quite dry.