You Don’t Need a Greenhouse to Grow Citrus Indoors

You Don’t Need a Greenhouse to Grow Citrus Indoors

  • Post category:Real Estate

Shattering the glass ceiling isn’t always a goal — not if you’re a certain beloved lemon tree growing in a Victorian-era greenhouse.

The tree in question, a Ponderosa lemon planted almost 125 years ago by the founder of Logee’s nursery, in Danielson, Conn., has been pruned to stay within bounds by three generations of his family. Even so, the nine-foot tree has delivered consistent bounties for more than a century — fruits that are closer to the size of a grapefruit than a lemon — with no sign of letting up.

And those prunings? Every year, they result in thousands of cuttings that are rooted for customers who will then grow them in pots — edible houseplants with a provenance.

In another greenhouse at the popular destination nursery, a century-old kumquat tree (Fortunella margarita), the bearer of little fruits to be eaten skin and all, is what the founder’s grandson, Byron Martin, refers to as “sort of a matriarch.”

Such venerable trees inspired the nursery’s impressive collection of rare and tropical plants, including fruiting ones, with an emphasis on those adapted to container culture.


In Mr. Martin’s more than 50 years at Logee’s — a company he owns and manages with Laurelynn G. Martin, his longtime business partner, former wife and the co-author of their recently reissued book, “Edible Houseplants: Grow Your Own Citrus, Coffee, Vanilla, and 43 Other Tasty Tropical Plants” — he has added to the assortment repeatedly.

Mr. Martin is constantly exploring options for customers who don’t have greenhouses but may be able to offer potted plants a bright window in the cooler months and a sunny summer outside. Among them is one of his favorites, a sweet lemon (Citrus ujukitsu) that bears delicious pear-shaped fruits and is probably more accurately described as a yellow-skinned strain of tangelo.

He also recommended the Citrus sinensis hybrid called Cipo, a sweet orange with weeping growth, which may not be ideal for a commercial orchard but makes a good candidate for a hanging basket.

Maybe the oddest of the nursery’s citrus plants is the Buddha’s Hand citron (a hybrid of Citrus medica), which has almost no pulp or juice. The extra-thick, somewhat sweet rind is the edible portion, suitable for zesting, eaten candied or used in marmalade. The fruit’s shape, a fistful of fingerlike structures, resembles a fleshy, many-petaled flower or perhaps a sea anemone.

There is nothing commonplace, either, about two fairly rare varieties with variegated fruit and foliage: The pink Eureka lemon (Citrus x limon) forms green-and-cream young lemons that mature into pink-and-yellow fruits; the delicious lemons of the tiger navel (Citrus sinensis) are green-striped, yellowish-green globes.

But honors for the showiest among the 57 types of citrus at Logee’s may go to a variegated Calamondin orange (Citrus x citrofortunella mitis), a hybrid of a kumquat and possibly a mandarin orange, with white-splashed leaves. Its abundant tiny sour fruits can be substituted for lemons or limes in drinks and baking, and make great marmalade.

This plant thrives in the same 10-inch clay pot it has been in for 35 years, Mr. Martin said — and no, he hasn’t ever repotted it with fresh soil.

“It’s no bigger than three feet from the floor to the top of the plant,” he said. “And it’s been that way for years and years and years.”

The little tree has been pruned, but not much else. “We’ve just simply given it fertilizer and water throughout all this period of time,” he said.

Take your inspiration from the art of bonsai, he suggested: “The fact that citrus can grow into trees is not going to happen in a small container. Just like bonsai, you literally restrict the root system by the size of the container.”

Many of the citrus trees in Logee’s collection would happily grow 10 or 20 feet tall, or even taller, if they were planted in the ground and left unchecked in a place where they’re hardy. But fortunately for those of us who are not in frost-free zones, that’s not the only way to grow citrus.

Which plant to start with, if you want to enjoy fragrant citrus flowers followed by homegrown fruit indoors?

Consider those like the popular Meyer lemon (Citrus x meyeri) — thought to be a hybrid of lemon and mandarin orange — with dwarf growth habits.

Choosing a lemon or lime tree has another benefit, as well: a longer flowering cycle. That means you could have fruit throughout the year, not just in one big flush, as you would with an orange, grapefruit or kumquat plant. A Meyer lemon tree promises a longer season with more of the less-acidic, sweeter, richer-flavored fruit that cooks favor.

“Lemons and limes are really great houseplants, because your productivity is pretty high,” Mr. Martin said. Even when pruned to a couple of feet tall, the Key lime (C. aurantifolia) and Persian lime (a hybrid of C. aurantifolia) can be quite productive.

“In container citrus, most of the pruning we do is just to maintain size,” he said. If a shoot comes up out of the top and starts taking over, for example, it’s usually removed.

But before you start pruning, he advised, think about the effect it will have on your harvest. Which potentially fruit-bearing wood are you willing to part with to create a well-shaped plant that fits your space?

Any needed thinning, Mr. Martin continued, can be done at flowering time, often in late winter or early spring, depending on the variety. Or maybe even better: after the fruit has set.

“Then you can prune with confidence,” he said, working around the fruit as much as possible while getting rid of any long, outreaching branches.

One kind of citrus that doesn’t want to be a tree and adapts to a pot without much convincing is also probably unfamiliar. The fruits of the shrubby little finger lime plants from Australia (Citrus australasica) are packed with loads of tiny bead-like vesicles, or fluid-filled sacs. Often referred to as “citrus caviar,” they are sharply sour and crunchy, and make a nice condiment for salads and drinks, or a garnish for a canapé.

Mr. Martin grows about 10 kinds of finger limes, both green- and red-fruited, including the hybrid Australian red lime. It is a weeping form that bears two-inch burgundy fruit and remains just over a foot tall, with occasional trimming required to keep it in shape.

Our primary job as citrus-plant parents, Mr. Martin said, is to provide plenty of sunshine and keep the roots healthy.

Citrus trees are susceptible to root pathogens, and “root disease is the main cause of citrus loss in containers,” he said. “When the soil remains wet or moist for too long, that’s when these problems start to arise.”

A clay pot — not a plastic one — is a key to promoting root health. Porous, unglazed clay transpires, or allows water to evaporate, more effectively than plastic, simulating a little drought stress, which is a good thing.

“If you grow them under some stress, it tends to eliminate that problem,” he said, referring to root disease. “A clay pot is definitely going to give the plant a quicker dry-down, meaning more drought stress than a plastic one.”

A fast-draining, peat-based commercial potting soil containing vermiculite or perlite and a small amount of fertilizer is a good basic medium, Mr. Martin said. But citrus tends to want a lower pH than is found in consumer mixes, preferring slightly more acidic soil (in the mid to low 5s on the pH scale).

If any signs of yellowing between the veins occurs — interveinal chlorosis, a sign that elements like iron may be rendered unavailable to the plant by an alkaline soil — a fertilizer labeled for acid-loving plants may help to correct it, he said. Otherwise, he recommended using a balanced fertilizer formula applied according to label directions during active growth, but backing off on fertilizer use in lowlight months.

You can reduce your fertilizer when you go into the winter,” he said, “or completely stop it, particularly if you’re not getting any growth.” When new growth begins in early spring, you can resume fertilizing.

There will be moments of panic for every new plant parent, including the first encounter with pests that may affect citrus, like scale insects, mites and mealybugs. To minimize pests, Mr. Martin suggests proactively spraying plants thoroughly with a Neem oil solution, diluted and applied according to package directions, before moving the containers back indoors in the fall.

That transition can be stressful for a plant — and for its grower. Leaves will drop, a normal but unsettling reaction to the reduction in light. Some fruit may drop, too, before ripening.

Unlike the pruning, this is not a moment that we can control, Mr. Martin said. The plant knows best, and the thing to do is trust it.

“They won’t hold more than they can really take care of,” he said, offering a bit of wisdom reaped from working beside citrus trees all these years.


Margaret Roach is the creator of the website and podcast A Way to Garden, and a book of the same name.

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by NYTimes