Houseplants to Leave Outdoors (For a While) in Fall

The florist’s azalea (Rhododendron simsii) is among the relatively few houseplants that greatly benefit from a fall spent outdoors in the cool air. Photo: plantsam.com

A few days ago, in the article Already Time to Bring Your Houseplants Back Indoors?, I explained that at the beginning of September, it was already time to think about bringing houseplants that spend their summer outdoors back inside, and also other tender plants you want to protect from the cold. That’s because the vast majority of houseplants are tropical plants and do not appreciate the gradual cooling that autumn nights bring. They prefer to be brought indoors before the nights turn cold.

Exceptions, Exceptions

Well, there are exceptions to any rule, so it’s not surprising that there is a small group of houseplants that aren’t really tropical in origin, but rather subtropical. In other words, in their native environment, they experience cool temperatures for part of the year, although not frost.

These plants, unlike the average tropical houseplant, will prefer to spend the fall outdoors and indeed can theoretically tolerate temperatures as low as 33 °F (1 °C), although it’s best not to not subject them temperatures quite that low. Instead, bring them in when the night temperature begins to regularly dip below 45 °F (7 °C). 

Even when you bring them in, by the way, keep them in a cool place if possible, at about 50 to 60 °F (10 to 15 °C), until spring. That way they can go through a bit of a winter as they would in their native haunts.

Plants That Like Things Cool in the Fall 

The following plants are all very tolerant of cool temperatures and you can leave them outdoors for a longer time than most other houseplants. Most, on the other hand, only tolerate fall cold, they don’t really need it and they’ll grow perfectly well if brought in early, along with their tropical companions.

For those marked with an asterisk (*), though, a cold autumn is almost a necessity. It tends to produce better growth and indeed, some will only bloom if they get a decent cold treatment.

1. Agapanthus* or lily of the Nile (Agapanthus spp.)
2. Agave (Agave spp.)
3. Aloe (Aloe spp.)
4. Aspidistra or cast-iron plant (Aspidistra elatior)
5. Bottlebrush (Callistemon spp.)
6. Buddhist Pine (Podocarpus macrophyllus)

7. Cactus*, including the Christmas cactus (Schlumbergera spp.)
8. Calceolaria* or pocketbook plant (Calceolaria × herbeohybrida)
9. Camellia* (Camelia japonica)
10. Citrus (Citrus spp., many species, but not lemons or limes)
11. Common ivy (Hedera helix)
12. Cordyline or spike dracena (Cordyline australis)
13. Crassula or jade plant (Crassula obtusa and others)
14. Dwarf pomegranate (Punica granatum ‘Nana’)
15. Dyckia (Dyckia spp.)
16. Elephant bush (Portulacaria afra)
17. Florist’s azalea* (Rhododendron simsii)
18. Florist’s chrysanthemum* (Chrysanthemum morifolium)
19. Florist’s cineraria* (Pericallis × hybrida, formerly Cineraria × hybrida)
20. Florist’s cyclamen* (Cyclamen persicum)
21. Florist’s hydrangea* (Hydrangea macrophylla)
22. Forced bulbs* (daffodils, hyacinths, tulips, etc.)
23. Fuchsia* (Fuchsia spp.)
24. Gasteria or ox tongue (Gasteria spp.)
25. Golden cypress (Hesperocyparis macrocarpa, syn. Cupressus macrocapa)
26. Holly osmanthus (Osmanthus heterophyllus)
27. Japanese aralia* (Fatsia japonica)

28. Jasmine* (Jasminum spp.)
29. Lady palm (Rhapis excelsa)
30. Lily* (Lilium spp.)
31. Mangave (× Mangave cvs)
32. Miniature rose* (Rosa cvs)
33. Mock orange* (Pittosporum tobira)

34. Norfolk Island pine (Araucaria heterophylla)
35. Oleander* (Nerium oleander)
36. Orchids (some genera, notably Cymbidium* and deciduous Dendrobium*)
37. Piggyback plant* (Tolmiea menziesii)
38. Plumbago* (Plumbago auriculata)
39. Primrose* (Primula spp.)
40. Snowbush (Serissa japonica, formerly S. foetida)
41. Strawberry saxifrage (Saxifraga stolonifera)
42. Venus flytrap* (Dionaea muscipula)
43. Voodoo lily (Typhonium venosum, syn. Sauromatum guttatum)
44. Wire vine (Muehlenbeckia spp.)
45. Yucca (Yucca spp., some species)