citrus in pots: how to grow, and overwinter it, with four winds growers
‘HOW CAN I OVERWINTER MY potted lemon tree indoors?” It’s the question of the moment from readers, as cold weather comes on. When it comes to citrus, I’ve often referred to advice from Four Winds Growers in California, with more than 60 years of experience and at least as many varieties. Learn to succeed with citrus indoors.
Four Winds Growers was founded around the idea of developing and promoting dwarf varieties of citrus to fit the scale of the new-home boom in post-war California and beyond–including on all those patios, and also in pots as the container-gardening trend began to take hold. Four Winds remains a family business, and a multi-generational one. It was taken over by the founder’s son, who ran it from the early 1950s until recently, when his son took charge, along with his daughter; her husband, and a grandson.
In his own home garden, Four Winds marketing director Ed Laivo has potted citrus that he has been growing for “upwards of 25 or even 30 years.” He joined me on the radio and podcast to share his tips on container growing and pest control. (The transcript of the Nov. 3, 2014 show is below.)
citrus-growing q&a with ed laivo
Q. Besides having more than 60 years of experience in dwarf citrus, there are some other impressive numbers in the Four Winds story, Ed. Like that you grow a quarter of a million potted citrus a year, for instance.
A. A quarter of a million trees a year, and about the widest selection of any company in the United States, yes. The company goes all the way back to 1946, to Floyd Dillon, one of the founders of the concept of growing citrus in the backyard. He conceptualized citrus as being “the fruit tree for the people,” and really started out with espaliering them.
Q. Like we do in the Northeast with apples and pears, for example—training them sort of flat and compact.
A. Yes, it works very well with citrus, too.
Floyd Dillon also developed the concept of the dwarfing rootstock at the time. There were some new things coming out of research, and he really gleaned on to them and then adapted them. Now they’re all common—in the industry, we’re all growing on that dwarfing rootstock now, because it’s wonderful and adaptable.
Q. You mentioned dwarfing rootstocks as one part of the equation, but what does “dwarf citrus” mean? Are these all grafted plants, as I infer from the use of the word “rootstock,” or are there natural genetic dwarfs, too?
A. The Meyer lemon [above] would be considered a natural dwarf; it’s a small tree, and it actually does well on its own root as well as being grafted. Four Winds for the most part grafts their trees.
I’ve grown on many different rootstocks, depending on their compatibility with a particular type of fruit tree. But the wonderful thing about citrus: It just does well in containers on any rootstock—that’s what makes it a wonderful tree for adaptation throughout the United States, because people can make it mobile.
Q. People have probably heard of Meyer lemon and perhaps the Key lime (also called the Mexican lime), but there are many other possibilities. I think I counted 60 varieties of dwarf citrus at Four Winds. Are they all suited to container culture?
A. Yes, all of them. It’s really the rootstock that determines whether a citrus tree can be grown in a pot for an extended period of time. Citrus are evergreen, but most deciduous trees, by comparison, have a very short time when they are comfortable in containers. The rootstocks are so aggressive; they physiologically need to be very expansive, and the trees really start to have trouble after some years in pots.
But remember, in Europe, some of those citrus on display in pots [above] have been in them for 60 or 70 years, and even longer. I think we’re talking about one of the most adaptable fruit plants to container growing, and that’s what has endeared citrus to people around the world.
It’s like raising fish in a fishtank: Some fish adapt to it, and some don’t. Some plants adapt to being grown in containers, some don’t.
Q. So compared to a deciduous fruit such as an apple, where it can only photosynthesize part of the year, having a confined root zone is not as much of a restriction for a citrus.
A. You only get away with it with an apple for maybe three years. Then they start to get little-leafed, where they don’t leaf out with any kind of vigor, and you really have to feed and water them aggressively or they don’t look good. Citrus doesn’t have that issue. A citrus plant’s demands [for water and fertilizer] grow with its size, of course, but it’s easy to sustain it.
A. …and mandarins—they’re the big ones now, very popular. There are many varieties of oranges, for instance, and calamondins [above], a very popular Filipino variety of fruit used in Filipino cooking, and also one of the more popular ones for growing indoors. It’s very accommodating, with beautiful fruit, beautiful flower, beautiful plant.
Q. What’s the Number 1 seller?
A. Meyer lemon! They’re grown in Canada, on patios in high-rises in New York City, as well as in people’s backyards in Los Angeles.
Q. So far we’ve mentioned adaptability to container culture, and evergreen foliage—both great attributes—but what other features make dwarf citrus a good choice for the houseplant lover or home gardener?
A. How about fragrant bloom? And then just the overall look—because it’s evergreen, it always looks rich, full, alive. And another thing that makes citrus so accommodating: You can just prune it and keep it nice and tidy.
Q. Do I need to prune to keep them “dwarf?”—or I can keep them growing, assuming the container is big enough?
A. I love pruning. I almost look at the word “dwarf” as being a mistake, because it almost gives people the idea that the plant does its size control on its own. I think you have to think of the beauty of being able to go in and create the shape.
Whether you want it to be a natural-looking form, or something more formal, citrus will accommodate that.
Q. What’s the timing of proper pruning?
A. Again, the plants are accommodating. A lot of people will tell you don’t prune citrus going into the wintertime, because of course them you can stimulate new foliage and that foliage can become susceptible to frost. That wouldn’t matter to someone in Florida or San Diego or the Southern seaboard, though. In general, my thought is as a rule, don’t prune when it’s going to be cold.
A. All the citrus are self-fruitful. If you want to have an orange, a lemon and a lime, you’ll have no problem at all having fruit on each.
Q. Do the different varieties as potted plants all have the same basic needs, culturally speaking, outdoors and in?
A. Sunlight is the most important, outdoors and indoors. You want to to give it the most sun exposure possible outdoors in the milder months, eight hours or more a day. If you’re bringing it inside, the sunniest window inside is your best choice.
Q. Yes, anything that’s evergreen needs light, even in winter.
A. I think one important thing to remember is that when you’re bringing citrus inside, generally you’re bringing it in with fruit on it. It’s going to ripen that fruit for the most part inside your house.
Q. What about temperature?
A. One of the biggest problems you have inside the house isn’t temperature, as much as lack of humidity. Inside the house is very dry, so you want to put it as far from heat sources as you can. It will take coolness of the house—but keep it away from dry heat.
Q. What’s the general hardiness?
A. About 25F to 32F is about the general tolerance level of citrus. When you get below 25 sustained, you’re talking sustained—and even below 32 on some varieties, like the Key lime you mentioned, which is very sensitive to cold. You get below 32 for over 3 or 4 or 5 hours in the evening, you may very well sustain damage on a Key lime.
Q. So we’re transitioning it well ahead of frost to indoors.
A. I love the word “transition,” to kind of acquaint it with its move indoors. Move it from that outdoor spot to maybe up against the house, and then maybe put it out in the garage early in the fall, to get it acquainted to moving inside—and then go ahead and stick it inside, rather than just put it right inside first.
Q. I think a lot of people skip those steps.
Now how cool can I go indoors—like what if I have a bright mudroom that’s only 50F, or a sun porch?
A. I’d use your own general comfort level. If you could go out in your sunroom in the evening, or at 5 o’clock in the morning, in your regular clothes, without a coat, and be comfortable—then it’s fine for the plant.
Q. What kind of growing medium?
A. I like acid potting mixes—the ones for azaleas, camellias, rhododendron. Citrus are acid-loving plants, which is something people don’t equate with citrus, because if they come from a desert environment you wouldn’t expect it, but they like acid soils.
I like a fluffy mix with a lot of large particle, so it really breathes well. I love a product called coir, a coconut product. It’s an excellent additive to potting soils, especially in the chunk form. It’s like little sponges that you put into your mix, and I like it to be about one-third of the mix, that you mix in.
It gives you water-holding capacity so that you water less, which is the next big problem with growing indoors. People tend to overwater indoors.
I also used organic fertilizers intended for acid-loving plants—again, for camellias and azaleas—and definitely organic, because you want to eat that fruit.
[A 101 on growing citrus in containers, from Four Winds’ website.]
Q. What pests must I be on the lookout for–and are there safe, sane ways to tackle them? I had to laugh when I saw that a non-toxic cleaning product made from oranges was one of the possible solutions mentioned on the Four Winds website.
A. The little soil gnats, or fungus gnats, are from overwatering. Immediately when you find those, back off with the watering.
Spider mites can be a big problem indoors—little dappling white spots on the leaves are an indication that you have them. The orange-based cleaner you mentioned can be used to treat them, and there are other remedies.
Scale insects are another possible problem, but I usually get a cloth and just wipe them off. In extremes you can spray with horticultural oil and things like that, if you have a heavy infestation.
If you watch your trees, and see scale, get a cloth and just wipe them off—that’s what I do and is a perfect way of controlling them in the home garden.
Q. Are you already in gear for the holiday shopping season?
A. Yes, citrus is a really popular gift—and why wouldn’t it be?
Q. Especially if you’re as good a grower as you are, Ed, with some of your plants 25 years or older. Thanks for the how-to.
enter to win your choice of citrus tree
I BOUGHT TWO lucky winners a $40 gift certificate (the contest is now closed) for their choice of a three-year-old citrus tree from Four Winds Growers—old enough to set fruit next year. All you have to do to enter is answer this question in the comments box way at the bottom of the page (after the very last comment):
Have you tried growing citrus, indoors or out? (Share some details if so.)
No answer, or feeling shy? That’s fine. Just say something like “count me in” instead, and I will, but an answer is even better. Two winners–United States only, with some restrictions on certain products in citrus growing states—were chosen randomly after entries closed at midnight on Tuesday, November 11, 2014.
get the podcast version of future shows
MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
(All photos courtesy of Four Winds Growers.)