Conservatories are great places to grow plants because they get a lot of light and they tend to be spacious. However, conservatories are usually unheated.
During the colder months and especially in winter, conservatories get too cold for most houseplants to survive in them.
In this article, we will go through the best houseplants for cold or unheated conservatories:
1. ZZ Plant (Zamioculcas Zamiifolia)
ZZ plants are tough in many different ways, but they are a great option if you need a plant that will tolerate a bit of cold.
They are attractive, with glossy, dark green foliage, and they don’t mind if the room temperature drops during the winter months.
They don’t like huge amounts of light, however, so choose one of the darker parts of your conservatory, or put up a shade for them in the summer.
Overall, ZZ plants are not tolerant to very cold conservatories, but if yours falls into the temperature range below, ZZ plants are great because they are a set it and forget it plant.
They require minimum attention to stay green and look beautiful.
Temperature: between 60 and 75 degrees F (15 – 24 °C)
Water: once every couple of weeks
Light: bright, indirect light
Soil: any well-draining soil
2. Sago Palm (Cycas Revolute)
Sago palms are beautiful houseplants and they are very tolerant of cold weather.
They will withstand temperatures as low as 15 degrees F for brief periods, although this sort of cold will kill them if it is allowed to continue for too long.
Sago palms are not particularly fussy about their lighting conditions, but prefer bright light when it is available. This makes them ideal for growing in a cold conservatory.
They prefer a bit of warmth, but they can tolerate even mild freezes provided they are short.
As long as they have bright light, Sago palms are the best plants for conservatories with temperature fluctuations (very cold in the winter and very hot in the summer).
Temperature: between 15 and 110 degrees F (-9 to 43 °C)
Water: don’t overwater; allow the plant to dry out in between waterings
Light: bright light to partial shade
Soil: rich, well-draining soil
3. Maidenhair Fern (Adiantum)
These plants have attractive, feathery foliage and grow lush fronds that sprout in all directions.
They grow well in containers, and prefer bright, indirect light.
They don’t mind cold too much, but prefer temperatures not to drop below around 65 degrees F.
If your conservatory gets very cold, therefore, they may not thrive. But if it doesn’t fall down under 60 F, Maidenhair ferns are a great choice.
Make sure that you keep your maidenhair fern damp, but don’t water it so much that its roots rot.
Temperature: Above 65 degrees F (18 °C)
Water: keep the soil moist and the air humid to keep the plant happy
Light: bright, indirect sunlight
Soil: rich, loamy soil, high in nutrients
4. Snake Plant (Sansevieria)
The snake plant is a popular houseplant because it is easy to grow and highly attractive. It has thick, leathery green leaves that look rather like snakeskin.
It will tolerate the cold, and most other adverse conditions well.
This plant also doesn’t need much light, so you can grow it in one of the darker corners of your conservatory without having to worry about whether it will thrive.
Snake plants are notorious for being one of the hardiest, low maintenance plants. They also grow tall making them perfect for the corner of a cold conservatory.
Being so tough, snake plants will do great in an unheated conservatory.
However, if your conservatory often drops to freezing or below, it may start to struggle.
Temperature: 60 to 75 degrees F (15 to 24 °C)
Water: lightly; this plant dislikes to be kept wet
Light: partial shade, rather than full sun
Soil: well-draining and sandy to aid quick drying
5. Cast Iron Plant (Aspidistra Elatior)
The cast iron plant, as its name suggests, is an exceptionally hardy specimen that will thrive in almost any conditions.
The cast iron plant has large, attractive leaves that are green all over, and it needs minimal care or attention.
This plant will tolerate temperatures as low as 60, but may die if they drop as low as 50, so make sure your plant is kept indoors during the winter.
However, unheated conservatories are more protected and usually have a higher temperature than 60 degrees F, which means the cast iron plant is a great low-maintenance choice.
Temperature: around 60 degrees F (15 °C) or higher
Water: water when the soil is dry, but not too often
Light: bright light or low light, but no direct sun
Soil: well-draining, acidic or neutral soil
6. Geranium (Pelargonium)
Geraniums are extremely popular houseplants, and there are many varieties, most of which are reasonably cold tolerant.
Geraniums will grow well in a cool conservatory as long as the temperature remains above 41 degrees F.
They can’t cope with frost, however, as the stems will freeze and suffer from permanent damage.
But unless you plan to move your geranium outside for winter, it will do great in a cold, unheated conservatory.
Another bonus is geraniums will bloom, giving your conservatory a splash of color.
Temperature: not lower than 41 degrees F, preferably over 65 degrees F (more than 5 °C)
Water: water them well throughout the summer, keeping the soil damp
Light: lots of light to bloom, but moderate light for growth
Soil: well-draining soil with peat and perlite
7. Ponytail Palm (Beaucarnea Recurvata)
The ponytail palm is also cold-tolerant and will cope with temperatures above 45 degrees F, although it does prefer slightly warmer conditions.
Ponytail palms are also fond of full sun, making them ideal for growing in a cold, unheated conservatory.
Don’t leave your ponytail palm outdoors if the temperatures are dropping below 40 degrees F; bring it into a sheltered environment like your conservatory to reduce the risk of the leaves freezing.
Ponytail palms also handle high temperatures well, making them a good choice for conservatories that are cold in the winter and hot in the summer.
Temperature: above 40 degrees F (4 °C) at the lowest
Water: allow to dry between watering
Light: full sun or bright light
Soil: use succulent soil with excellent drainage
8. Aloe Vera
This extremely popular houseplant prefers warmer temperatures, but it is cold-tolerant and will grow happily enough in a cool conservatory.
Protect it from very bright sun and from sudden dips in temperature, and move it to a warmer room if it shows signs of suffering from cold damage.
Don’t leave it outdoors in the winter or in a conservatory that drops below freezing, or it will die.
However, for cold unheated conservatories or ones that have big temperature fluctuations between summer and winter, aloe vera is a great choice.
Temperature: between 55 and 80 degrees F (12 to 27 °C)
Water: wait until the soil is almost dry and then water
Light: indirect sunlight or gentle direct sun
Soil: well-draining potting mix or succulent mix, or a combination of both
9. Natal Lily (Clivia)
A particularly beautiful addition to any room that’s on the cold side, the natal lily has bright flowers and attractive green foliage.
It is green throughout the year, regardless of the temperature, and will cope with low light as well as cold.
It will not deal with the frost, however, so make sure temperatures don’t drop below 40 degrees F if you plan to grow one of these plants.
Natal Lillies however will make for a stunning addition to the typical cold conservatory.
Temperature: above 40 degrees F (4 °C)
Water: water regularly throughout the summer, but less frequently in winter
Light: bright light but no direct sun
Soil: very rich soil that will drain well
10. Lemon Tree (Citrus Limon)
If you have ever fancied growing a citrus plant or a lemon tree in particular, a cool conservatory (or a hot one) is a good place in which to do it.
Lemon trees are some of my personal favorites when it comes to conservatory plants.
These plants have an amazing smell and although they prefer hot temperatures, they will tolerate cold.
In general, they should be kept between 50 and 80 degrees F, but they will put up with brief dips as low as 40 degrees F.
Lemon trees are a very good choice for conservatories that experience big temperature fluctuations between summer and winter, as long as they are getting enough light.
Temperature: 50 to 80 degrees F (10 to 27 °C)
Water: consistent and regular watering once the soil starts to dry
Light: at least 6 hours of bright sun per day
Soil: slightly acidic, dense, well-draining soil
11. Orange Tree (Citrus X Sinensis)
If a lemon tree doesn’t appeal, an orange tree is also cold tolerant and offers many of the same advantages.
These plants can cope with temperatures as low as 45 degrees F temporarily, although they do prefer more warmth overall.
This makes orange trees perfect for cold, unheated conservatories that get enough sunlight.
Although lemon trees are hardier and provide fruit more easily, whatever you choose between these two is more a matter of aesthetics than anything else as both will be a great addition to your cold conservatory.
Temperature: keep them above 55 degrees F (12 °C) at all times
Water: once or twice a week in summer, less often in winter
Light: 6 hours of bright sun per day
Soil: well-drained, acidic soil
12. Chinese Evergreen (Aglaonema)
Chinese evergreens are popular plants with amazing foliage, often speckled and variegated.
This plant can handle temperatures as low as 55 degrees F, although it prefers to be kept between 68 and 77 degrees F most of the time.
Chinese evergreens are hardy plants and an unheated conservatory is usually fine for it to grow in.
However, try to keep them away from the freezing cold and don’t leave doors or windows open, especially if the temperature outside drops below freezing.
Temperature: between 55 and 77 degrees F (12 to 25 °C)
Water: when the soil starts to dry, once a week or less often
Light: medium to low light
Soil: well-draining soil
13. Spider Plants (Chlorophytum Comosum)
Spider plants are known for being easy to grow, hardy plants, and this is true for their temperature tolerance in particular.
A spider plant will survive in temperatures as low as 55 degrees F, making them great plants for cold conservatories.
However, keep in mind that they will die if you try to leave them outdoors in the winter.
Spider plants do best with indirect sunlight, so it’s a perfect plant to keep in the corner of an unheated conservatory and forget about it.
Temperature: between 55 and 65 degrees F (12 to 18 °C)
Water: allow to dry out a little before watering
Light: partial shade
Soil: almost any, but prefers loamy soil
Best Small Cold Conservatory Plants
If your conservatory is not particularly spacious, you may find that it helps to choose plants that are small.
It can also be a matter of design, maybe you want to complement your bigger plants in the corner or you have a small table in your conservatory that could use a tiny houseplant.
Here are the best small, cold-tolerant conservatory plants:
1. Christmas Cactus (Schlumbergera)
This small plant will tolerate low temperatures, but prefers them to remain above 50 degrees F. It can grow to around 18 inches tall and wide.
2. Wax Hoya (Hoya Kerrii)
Although this plant can grow up to 15 feet, it usually starts at around 5 inches and can be kept small by constricting the pot size. It’s perfect for a small cold conservatory!
3. Moth Orchid (Phalaenopsis)
When not in bloom, this plant will cope with temperatures as low as 61 degrees F at night, making it perfect for an unheated conservatory.
4. String Of Pearls (Senecio Rowleyanus)
With temperatures above 50 degrees F in winter, the string of pearls should thrive in cold conservatories.
5. Angelina (Sedum Reflexum)
A fern-like succulent, Angelina sedum is a very hardy plant that endures cold temperatures well. It will thrive in a cold, unheated conservatory.
6. Hen-And-Chicks (Sempervivum)
This delicate succulent is small and pretty, but will tolerate the cold of your conservatory without problems.
7. Zebra Cactus (Haworthia)
Although they prefer warmer temperatures, they will deal with anything as low as 40 degrees F for short periods. The Zebra cactus also tolerate high temperatures very well, so they are perfect for conservatories that get cold in the winter and very hot in the summer.
8. String Of Turtles (Peperomia Prostrata)
An unusual addition to your unheated conservatory, the string of turtles will handle chilly temperatures as long as it gets enough light. This plant will cope with temperatures as low as 64 degrees F.
Best Big Cold Conservatory Plants
If your conservator is large, you may want some big, showy plants to fill it with.
Big houseplants are also a great addition for conservatory corners, filling otherwise useless space with a splash of green.
Here are the best big houseplants for cold conservatories:
1. Dragon Tree (Dracaena)
These striking plants can reach up to 10 feet tall in some cases, making them ideal for an impressive conservatory display. It can handle temperatures as low as 55 degrees F and as high as 80 F, making it a great choice for conservatories cold in the winter and hot in the summer.
2. Jade Plant (Crassula Ovata)
Jade plants can get to around 5 feet tall, with thick, shiny leaves. They are striking and will tolerate temperatures around 55 degrees F.
Depending on the variety, philodendrons can reach around 20 feet tall and up to 6 feet wide in the right conditions, and they will easily tolerate a cool conservatory.
4. Fiddle Leaf Fig (Ficus Lyrata)
This plant can reach a full 50 feet, but usually only manages around 10 feet when grown indoors. They handle temperatures as low as 55 degrees F, making them a good addition to an unheated conservatory.
5. Lady Palm (Rhapis Excelsa)
If you are a fan of the spiky look, the lady palm will make a lovely addition to any cool conservatory. It is hardy and will tolerate any temperatures between 20 and 100 degrees F, although it prefers warmer environments.
6. Monstera Deliciosa
These plants will cope with temperatures as low as 55 degrees F as long as the temperature decrease is gradual, but generally prefer to be kept above 60 degrees F.
7. Lemon Cypress Tree (Cupressus Macrocarpa ‘Goldcrest’)
This plant will survive in temperatures as low as 20 degrees F, and it enjoys humidity. It can grow to 10 feet tall when grown outdoors. The cypress lemon tree is even tougher than the classic Lemon tree, handling a cold conservatory with ease.
Although it depends on the variety, there are winter-hardy Yuccas that can tolerate temperatures of around 50 degrees F or lower, easily handling unheated conservatories.
Conservatories are a great place for houseplants because they usually have plenty of sunlight, but the downside is they are usually colder than the rest of the house.
Although many regular plants would struggle to survive the winter in a cold conservatory, there are many plants out there that can handle the low temperatures well.
Use this article to choose wisely, and you will turn your conservatory into an indoor garden in no time, even if it’s on the chilly side!