Temperature Requirements for Indoor Citrus Trees

Whether you want to grow some kumquats for your kitchen or fill your house with the sweet aroma of lemon blossoms, growing citrus trees indoors is a worthy pursuit offering all sorts of benefits. However, these trees do require a bit of care. One of the essential parts of keeping your tree healthy is providing the proper temperature and humidity. Unsure how to do this? Follow along for all you need to know about indoor citrus temperature and humidity requirements at home.

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Indoor Citrus Tree Temperature and Humidity Tolerances – The Essentials

The majority of indoor citrus trees prefer temperatures between 60-90ºF with moderate to high humidity. While some citrus, such as yuzu and kumquats, can tolerate below-freezing temperatures, they will thrive in warmer temperatures.

Humidity and Temperature in Citrus Trees’ Native Environments

While scientists aren’t sure exactly where various citrus species arose, they think most types of citrus are native to areas in South and East Asia. Since this is such a large area, temperature and humidity vary quite a bit.

In the summer, high temperatures range between 80-100ºF with high humidity. Winters are typically mild, with low temperatures around 40-60ºF and moderate to high humidity. Of course, there is some variation in these numbers, depending on the exact location.

Citrus species including Mandarin oranges and lemons are thought to be native to Southern China, where temperatures typically range between 50-90ºF

Limes are thought to be native to Indonesia, where temperatures are quite balmy. Even in the coldest parts of Indonesia, it’s rare for temperatures to drop below 50ºF.

However, some types of citrus are used to colder temperatures. Kumquats and yuzu, often considered the most cold-tolerant citrus, are native to Southeast and Central China. In colder areas, temperatures often drop below freezing, yet these citrus trees survive.

Fortunately, it’s easy to manipulate indoor temperatures to match those present in a citrus tree’s native range. Just turn on the heat in the winter and avoid placing your tree near cold drafts.

Keeping the humidity high is a bit more difficult, but you can accomplish this with a humidifier or spray bottle.

Signs Your Indoor Citrus Trees are Exposed to the Wrong Temperature/Humidity

Low Vigor

While many people think cold temperatures will cause extreme damage, they can also impact trees in subtler ways. While citrus trees can survive temperatures around 50ºF, constant exposure to these temperatures will slow their growth.

If your tree looks stunted or seems to be delayed in flowering and fruit set, your temperatures may be too low. This is especially true if summer temperatures are below 60ºF.

Boosting your temperatures to 80ºF or even 70ºF will improve your tree’s overall health.

Flower Drop

The moment you’ve been waiting for has arrived – your citrus tree is producing those sweet-smelling flowers! However, you notice a large number of flowers or leaves have dropped before fruits have formed.

Some fruit drop is natural as trees thin their future fruit load. But a drop of more than 50% is cause for concern.

While flower drop has numerous possible causes, exposure to cold temperature is one possibility. Keep your tree away from cold drafts and ensure the temperature stays above 60ºF.

Crisp Leaf Edges

Something is awry if you notice your tree’s leaves are developing discolored, crisp edges. The most likely issue? Low humidity.

If you find your lips and skin feel dry, it’s likely the humidity is too low for your tree. Even if your tree is well-watered, low humidity can cause issues. If your air is extra dry, you’ll need to boost the humidity, so it’s in the moderate to high range.

To do this, use a humidifier, set out a tray of water, or give the air around your tree a good mist.

Ideal Temperature and Humidity for Indoor Citrus Trees

Most indoor citrus trees will grow the best when air temperatures are between 60-90ºF.

While this is the ideal temperature, most trees can tolerate temperatures outside this range.

Properly hardened citrus trees can survive freezing temperatures, and some varieties of kumquats, yuzu, mandarins can survive temperatures in the low 20s. However, this doesn’t mean you can turn off your heat and watch your tree flourish.

When trees are planted outdoors, they typically experience a gradual decrease or increase in temperature as the seasons change. This allows the tree to become adjusted to colder weather. When freezing temperatures arrive, the trees are likely to survive.

On the other hand, indoor trees are typically kept at a relatively consistent temperature. If your trees experience a sudden drop in temperature, they will likely suffer.

One more note on this point: although trees may survive temperatures outside of their ideal range, they won’t thrive in these temperatures. Temperatures below 50º will often set your tree back a bit.

As far as humidity goes, all types of indoor citrus trees prefer moderate to high humidity.

How to Choose a Location for Your Indoor Citrus Tree

To keep your citrus trees happy, avoid placing them in areas where they experience large swings in temperature. This means keeping them away from air conditioning vents, frequently-opened exterior doors, and radiators.

Since citrus trees like lots of bright, direct light, consider placing them near a south-facing or west-facing window. As long as this area doesn’t receive intense swings in temperature, it’s a good choice.

How to Boost Humidity in Your Home

Since citrus trees love lots of humidity, you might need to boost the humidity levels in your home. This is especially true during the winter when heaters dry out the air.

While a humidifier is the best way to increase the humidity rapidly, it’s not the only option. Placing your planter on a tray filled with rocks and water will boost the humidity a bit. Just make sure your plant isn’t sitting in the water.

Regularly misting the air around your tree with water will also increase the humidity. However, you’ll need to do this every day to keep the humidity high.

Caring for Indoor Citrus Trees in Spring and Summer

Since citrus trees are native to regions with hot summers, keeping temperatures high is important. While this typically isn’t a problem outdoors, you might find yourself cranking the AC to keep yourself cool.

With this in mind, check the temperature of the room your tree is in. If it’s below 70º, consider lowering the AC. Also, make sure your tree is in a bright area, where temperatures tend to be a bit warmer.

Another option is to move your tree to a sunny location outdoors. If the temperature is warmer outside, this is typically the best move. Just make sure to bring your tree back inside once temperatures start to dip below 60ºF regularly.

This is also the best season to consider repotting indoor citrus trees if needed.

Caring for Indoor Citrus Trees in Winter

Once the darker days of winter hit, citrus trees can handle a bit colder temperatures. With that said, you’ll want to keep temperatures above 60ºF.

Another thing to keep an eye on during the winter is the humidity. As heaters dry out the air, your tree may need a boost of moisture. Set out a tray filled with water or give your tree a daily spritz of water.

Wrapping Up

While citrus trees may seem a bit intimidating to care for, all you need is the proper knowledge. Now that you know the ideal temperature and humidity for indoor citrus, you can confidently add your tree of choice to your home.

How to Grow Citrus Trees at Home:

For everything you need to know about how to grow and care for citrus trees indoors at home, see our essential guides to:

Briana Yablonski

Contributing Editor | Full Bio | + posts

Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.