For those of you who thought growing citrus trees was impossible in any place with cold winters, you’re in for a pleasant surprise! It’s quite easy to grow dwarf citrus trees in pots and move them inside to a sunny window for the winter. Homegrown lemons, limes, oranges, and even grapefruits will do a lot to liven up those gray winter months between outdoor gardening seasons, because most citrus fruits ripen in the winter. I know: winter fruit–who’d have thunk it? But having tasted my first harvest this past November and December, I’m a believer!
I’ve already written a post about buying citrus trees and planting them in pots. But I’ve been asked to post something about ongoing care. So here it is.
The most important thing to remember is not to overwater. Remember that citrus trees grow very well in southern California, where there is barely any rain. They like their soil on the dry side. On the other hand, you can’t neglect watering them completely. My rule of thumb is that, when the plants are outdoors, in cool temperatures they’ll only need a good watering once a week (whether that comes from me or the sky). In warm temperatures, they’ll probably need watering twice a week. Indoors, once a week works.
Don’t think that, because the surface of the soil is dry, the trees need to be watered. It’s the moisture content of the center of the soil that counts. And, again, citrus trees like it on the dry side. You’ll know if your trees are hurting for water because the leaves will start to curl up a bit. Don’t go quite as long between waterings next time.
Now, just because citrus trees like their roots fairly dry doesn’t mean they don’t like a little humidity on their leaves. When the trees are inside in winter and not getting their daily dose of dew, it’s a good idea to spritz a little water on their leaves each morning. Makes them feel more at home. 🙂
When is the right time to bring the trees inside for the winter? When there is any risk of frost. Frost and citrus trees do not like each other. When frost is any kind of possible, you need to bring the trees indoors and find them a sunny window where they’ll get at least six hours of direct sun each winter day. Of course, when days are still warm, you can put the trees out during the day and bring them inside at night. Until they get so big that moving them more than twice a season is out of the question.
In the spring, when the weather starts warming up and there’s a whole day of sixty-degree weather, you might be tempted to put your citrus trees outside all day. Don’t. The poor things have been inside all winter and they’re unaccustomed to the outdoors. Even a light breeze and a warm sun on all sides can stress a plant that’s grown used to the still, shady air inside. They need to be acclimated gradually. Each day, they can spend an hour to an hour and a half longer outside. This process is called “hardening off”–that’s not just for vegetable seedlings! It applies to any of your houseplants that you might want to put outdoors. Get them used to their new environment gradually.
Every now and then, your trees will need to be fed. They’ll use up all the nutrients in their soil and start going hungry. If it gets bad enough, their leaves might start turning sad colors and falling off. Don’t let it get that bad. Every couple of months, sprinkle a little fertilizer in their pots. It’s important to use a mix tailored to acid-loving plants. You don’t want anything with lime in it. Since I mix my own fertilizer, I use a mix of 4 parts soymeal, 1 part bone meal, and 1/2 to 1 part kelp meal (that stuff’s expensive, but important). I might use a 1/3 cup of fertilizer per 12″ pot.
Finally, your trees are going to grow. And at some point they’re going to outgrow their first pots. Don’t wait as long as I did to repot. This little lime tree is sadly root bound. He should have had a new pot a year ago at least. But I didn’t know until I un-potted him that he’d done so much growing underground!
At the same time, you don’t want to use pots that are too big for your plants, as it’s harder to keep the moisture level of the soil correct. When you repot, fill the new pot with the same soil mixture you used originally. (Details about the mixture I use can be found here.)
I think that’s it. If you follow these simple guidelines, your trees should flourish and provide you with much winter cheer! But do remember: citrus fruit takes a long time to ripen. To find out just how long, check out the post “How Long Does a Lemon Take to Ripen?”
Feel free to ask me any questions you may have in the comments section below. Happy growing!