With temperatures in Austin, Texas getting as low as 15-20ºF, I’ll more than likely have to bring my dwarf citrus trees in this winter. While most citrus trees have similar needs, in this post, we’ll be looking at lemon trees since they’re the most popular. So, at what temperature do you start bringing lemon trees indoors?
The best temperature to bring lemon trees indoors is when it starts dipping below 45ºF (7.2ºC). Beyond that, you definitely would want to stay away from freezing temperatures (32ºF and below). Wind chill and humidity are also factors to consider, so 45ºF and up remain ideal temperatures.
Now that we know the minimum temperature for lemon trees, what about all the other factors? Like, what if we can’t bring them indoors? And are there ways to keep them warm? Let’s take a look.
When to bring lemon trees indoors
Lemon trees thrive in warm and humid environments, usually in tropical or subtropical regions. This makes many southern states in the US prime locations to grow them. The problem is, most of these states also have a high probability of frost. Since lemons, and most other citrus trees, take a long time to grow, it would be disappointing to see them killed off in the winter.
While each state has different weather in the winter, of course, here’s a chart that should give you an idea of the average winter temperature you should expect in your state (followed by its hardiness zone directly after).
|State||Average Weather in Winter|
If your state has a hardiness zone of 10b or lower, then you should highly consider bringing your lemon tree in before the first frost.
As cool as it would be, there’s not an exact time of year when you should bring in your lemon tree, as weather constantly varies. Even meteorologists still get it wrong often (no offense to them, I couldn’t do any better).
The best way to know when to bring them inside is to talk with your fellow homesteaders and ask what they do with their citrus trees in the winter. Otherwise, checking the weather once a week to see if you need to bring your lemon tree inside would be a good call.
If you’d like a bit more of an automated solution of checking the weather, I might have something for you.
If you don’t already know, some weather applications on smartphones have some custom reports. For example, if severe weather or a storm is coming in last minute, you can have the app set up to get an alert. Additionally, you can also set custom alerts to get notified when the temperature is getting too hot or cold. This could be perfect for the somewhat unpredictability of frost. I’ll link the apps below.
iOS – Forecast Bar
Google Play Store – Custom Weather Alerts
Feel free to take a look (the apps are free to download) and see if it’s worth it for you. Please note: some of their custom features require a paid plan.
What temperature will kill a lemon tree
Lemon trees start to get damaged when freezing temperatures occur (32ºF and below). When they fully mature lemon trees can get pretty durable, so they can occasionally handle brief periods of cold weather under 29ºF. However, they won’t last long, so make sure to protect them however you can.
Lemons typically cannot grow in cold weather due to their subtropic and tropical origins. If they remain outdoors in weather below 30ºF, they’ll start losing blossoms and smaller fruit. When the temperature dips to the early 20s, leaves will become damaged and fall off.
At this stage, lemon trees will have a slim chance of surviving. While they can lose leaves and blossoms and still recover, chances are they won’t survive long if the cold weather continues.
How to protect outdoor lemon trees from frost
If your lemon tree is outdoors, and frost is approaching, you might want to keep a close eye on it and protect it if you can. Start by taking a thick cloth, or other insulating material, and wrap the majority of the tree. The primary focus should be keeping the rootball warm.
Every homestead has different resources to work with, so to help spark some ideas, here are a few ideas to hopefully help you keep your lemon tree warmer while outside this winter.
- Put it next to a wall that gets a lot of sun
- Wrap the trunk in cardboard
- Cover it with burlap, tarps, or sheets
The most important goal here is not to allow the rootball to freeze. Wrapping the pot with insulation such as hemp fabric, fleece, or cardboard can help keep it warm. If you’re wrapping the entire tree, try not to put too much pressure on the foliage. Also, consider adding a frame if you’d like to help preserve the leaves and any potential fruit.
How to take care of lemon trees indoors
If you do decide to move your lemon tree indoors during the winter, make sure that it gets as much sunlight as possible and it doesn’t get too hot. Central-heated rooms are generally not a good place for them as it will become too warm and often lack humidity.
I know that doesn’t leave you with many options, so you might need to get creative. Depending on where you live, how cold your house gets, and how much sunlight you get indoors, there are a few places around the house that might help.
- Sunlit window
If your house looks like mine, you might have a few problems with these. First, the garage might get too cold. In this case, you might want to cover your lemon tree with a blanket to increase the temperature. Unfortunately, this means it won’t get much sunlight.
With sunlit windows, this can also be hard because of the direction you’re facing. There’s a chance you might get little to no sun from the window. However, windows can still be a great location because of the lack of insulation from the glass. The cold from the outside will balance some of the heat from the house. Just make sure the placement isn’t too close to your heating element.
If you decide to keep your lemon tree in the garage or in the house, when the temperature isn’t freezing, try taking it outside whenever you can. Also, keep in mind that when lemon trees are stuck inside, pollinators, like bees, cannot reach them. A workaround is for this is, again, to move them outside during the non-freezing temperatures during the day, or you can pollinate them by hand.
And last, while greenhouses are super practical and would be a nearly perfect solution for your lemon tree, many people simply don’t have enough room or cannot budget for them. However, if you can get a greenhouse, you may want to consider it as your growing options during the winter will expand well beyond lemons. Avoid fertilizing your potted Meyer lemon tree in the winter since it will be mostly dormant.
What are the most cold-hardy citrus trees?
The most cold-hardy citrus trees include tangerines, kumquats, and Meyer lemons. These trees can occasionally handle temperatures that dip below freezing. If you’re considering grafting, using trifoliate orange rootstock is a common way to help build cold resistance into citrus trees.
How many hours of sun do lemon trees need?
Most citrus trees need a minimum of eight hours of daily sunlight. For this reason, it can be hard to keep a dwarf lemon tree indoors. However, there are workarounds. You can keep a lemon tree indoors if you have a location with enough light, such as a sunny window, grow-lights, or a greenhouse.