Do you know the lemon cucumber? It’s an actual cucumber cultivar—Cucumis sativa “Lemon”—with round fruits about the size of small orange and even a protrusion at the tip much like the navel of a navel orange.
The fruits start off light green, but turn yellower as they mature. They’ll be lemon yellow by the time of harvest, that is, assuming you want to harvest them early, for their fleshy fruit. They have a very mild flavor and, unlike, other cucumbers, no bitterness. And, again, unlike others, they’re quite sweet, with a Brix of 5.4%. At this stage, many people feel lemon cucumbers have a lemony taste or flavor, whence the name. And quite a few prefer their extra-mild flavor to the more typical, somewhat bitter, burp-causing garden cucumber. (See Belch No More with Burpless Cucumbers?)
If you want to harvest your lemon cucumbers for their seeds (for next year’s sowing, for example), you need to let them mature further, letting them become orange or even brown. But at that point, they will no longer be edible.
Where Does the Lemon Cucumber Come From?
The story goes that a self-taught hybridizer created the lemon cucumber in the early 20th century by plucking an orange blossom from his daughter’s bridal bouquet and using its pollen to fecundate a garden cucumber flower. The result was a rare intergeneric hybrid, a cross between an orange and a cucumber, with the size, shape and color of a citrus, but the crispness and seediness of a cucumber.
So, what do you think?
Well, that’s nonsense, of course. ‘Lemon’ is just a cucumber. It carries no citrus genes. You can’t cross a cucumber, in the squash family (Curcubitaceae) with a plant in the citrus family (Rutaceae). It would be the equivalent of crossing a dog with an ostrich!
Old As the Hills
In reality, the lemon cucumber is probably just a very ancient cucumber. A true heritage vegetable, as it’s very similar to the wild cucumbers of India. This is where botanists believe all cucumbers originated. Some of these had a rounded shape and yellow or red skin, although also bore a considerable number of long spines as well. (The lemon cucumber skin is nearly smooth, bearing only a few tiny, inconsequential black spines.) This incongruous lot were the ancestors of today’s garden cucumbers.
Suspicions are that not only did the lemon cucumber’s ancestors originate in India, but that it was also developed as a crop there. Today Indian farmers grow a wide range of shapes, colors, textures and flavors of cucumbers and the lemon cucumber wouldn’t even stand out from the crowd.
Its lack of bitterness and ease of digestion are due to it being low in cucurbitacin. If you don’t usually like cucumbers, bite into a ‘Lemon’ cucumber. It’s like a very mild, very sweet cucumber; a taste most people appreciate.
American Samuel Wilson’s catalog was the first to offer ‘Lemon’ cucumbers. That was in 1894. Here is part of the description: “They are considered a great dainty by those who are fond of that popular vegetable. They have all the desired qualities of a good cucumber, slightly flavored with lemon, which gives them a decided advantage over the common kind.” Soon, it was fairly widespread in both the Old and New Worlds under the cultivar name ‘Lemon’.
These days, given the great popularity of heritage vegetables, seeds of ‘Lemon’ cucumbers are not at all hard to find. Look online and you’ll be surprised at how many catalogs offer them. I grew a few plants myself this summer, for the first time in over 40 years.
Why Is the Lemon Cucumber Round?
Wild cucumbers have either 3 or 5 locules: compartments in which seeds are produced. Garden cucumbers have 3. As with peppers, this leads to a naturally oblong shape. ‘Lemon’ has 5 and this naturally gives it a more rounded form. Certainly, however, developers of ‘Lemon’ must have done some tweaking, selecting the roundest fruits in each generation to stabilize its now near perfect tennis ball shape.
If I had to rate the ‘Lemon’ cucumber on anything other than originality or mild flavor, I don’t think I’d give it great grades.
It’s slow to mature, not very productive and certainly not very disease resistant. However, it has been used in hybridizing to introduce reduced cucurbitacin and other traits. And if any reader has an interest in trying to develop round cucumbers, it could certainly be part of your hybridizing program.
Other than that, it’s a standard, easy-to-grow cucumber. Start it indoors in the early spring and plant it in the garden or a container in the summer. You can read more about how to grow cucumbers here: 10 Tips for Growing the Best Cucumbers.
I would not, however, recommend trying to play tennis with the fruits, as tantalizing as their perfectly round shape might make that possibility seem!
To read more about the ‘Lemon’ cucumber, go to the site: Origin and Characterization of the ‘Lemon’ Cucumber where a full report by R.W. Robinson of the Horticulture Department at Cornell University awaits you.