Most people recognize an eggplant fruit as something they see in the supermarket and probably use eggplants in cooking, yet I suspect most gardeners have never tried growing one. Let’s see if this article will help change that!
What Is It?
The eggplant (Solanum melongena) is in the nightshade family (Solanaceae). It’s an annual plant with white or purple star-shaped flowers, usually rather large leaves, paddle-shaped and often coarsely lobed. Its fruit is botanically a berry and contains numerous small seeds surrounded by spongy white flesh. It’s usually considered a vegetable, since it is savory rather than sweet, and is served cooked.
We can’t seem to agree on what to call Solanum melongena. It’s called eggplant in the USA, Canada, New Zealand and Australia, aubergine (the French name of the vegetable) in England and Ireland and brinjgal in Asia and South Africa. But, whatever the name, it’s a great vegetable and one well worth learning to grow.
In this article, I’ll use the name eggplant, the one I’m most familiar with, but you can mentally substitute the name of your choice as you read on.
A Long and Complex History
Oddly enough, the eggplant doesn’t exist in the wild. It was derived from a wild plant native to Africa, the Middle East and India, the thorn apple or bitter apple (S. incana) with possibly input rom other related species. Very thorny, with a bitter fruit, this plant grew as a weed throughout the region and is perhaps the hedge of thorns mentioned in the Bible. It’s hard to imagine that our ancestors thought of consuming anything from such a nasty-looking plant, but they obviously did, using special cooking techniques to reduce the fruit’s bitterness. So, they slowly domesticated it, choosing to resow seeds of plants that weren’t as prickly or bitter as the others. Over many generations, the eggplant as we know it, S. melongena, was born.
Now, this all happened in prehistoric times, so it’s hard to pinpoint when the first true eggplant came about. Scientists believe the fruit was first domesticated in India, but it’s possible that it was also domesticated independently in China or elsewhere in East Asia.
At any rate, the cultivation of eggplant was already widespread in Asia by at least 500 BCE, as subfossils of eggplants are common in middens of that period. However, no trace has been found in Ancient Greece or Rome, showing their inhabitants didn’t know it.
The aubergine spread gradually west, eventually reaching the Middle East from where, in the 9th century, Arabs introduced it to Africa and, from there, in the 14th century, to Italy. The Arabic connection shows in the name aubergine, derived from the Arabic al-bādindjân as pronounced in France, the Arabic term itself taken from a Persian word for the plant.
Europeans did not welcome this new vegetable with open arms, though. They saw its resemblance to other plants in the nightshade family known for their toxicity, such as bitter nightshade (S. dulcamara). Thus came the idea that eating an eggplant would drive the devourer crazy, hence its Italian name of the time, mala insana, or apple of madness. For a long time, eggplant was grown strictly as an ornamental for its beautiful purple flowers and attractive fruit; most Europeans wouldn’t dare eat it!
But Italians also called the fruit “melanzana”, also derived from Arabic through a complex process. That’s where Linnaeus found the term melongena, giving the plant the botanical name it still bears, Solanum melongena.
It was the gardeners of Louis XIV who deserve credit for truly introducing the eggplant to the European table in the 16th century. They served it to the king, who loved it, and if the Sun King liked something, everybody had to at least pretend to like it. Thus, the vegetable gained prominence and eventually became to be part of everyday recipes in southern Europe, where it grew well, such as moussaka and ratatouille.
So much for Europe, but North Americans were still not enamored of this new vegetable. It was only under until the influence of Italian and Asian immigrants in the 20th century that the eggplant was truly accepted in the United States and Canada. The situation in Australia and New Zealand is similar.
Different Colors and Shapes
Even if we mostly see purple pear-shaped eggplants of a fairly large size in our supermarkets, as a gardener, there is a wide range of shapes and colors to choose from.
The fruit can be small and egg-shaped (guess where the name “eggplant” came from?) or large like a melon. In addition to the egg and pear shapes we know best, it can also be round or cylindrical. And the color ranges from white to yellow, orange, pink, mauve, purple, green or bicolor. Finally, while large fruits are usually produced individually, the small ones often come in clusters.
Note that the skin also differs. It can be bitter, especially in Asian cultivars, while in older European cultivars, it tends to being hard and inedible, in which case you only eat the flesh. More and more modern eggplants, however, have a thin, soft skin that can be eaten if they’re harvested young.
Eggplants Like It Hot
The success of eggplant cultivation used to be limited to areas with long, hot summers, but there are now short-season varieties, some with a days-to-maturity rating of only 50 to 60 days, that can be adapted to cooler climates. Even so, you’ll need a sunny location protected from the wind. In fact, in many areas it’s better to grow your eggplants in a greenhouse, a hoop tunnel or some similar shelter. I grow mine in my cold frame or in a temporary greenhouse, that way I can open them on warm days and close them at night if I figure it will become too cold. You also need them open during the day during flowering so bees can visit.
Only in regions with long hot summers, say, south of the Mason-Dixon line, can you consider sowing eggplants directly in the garden. Everywhere else, start the plants indoors 8–10 weeks before the last frost date in your area. Or buy started plants from a nursery. It’s best to sow eggplants in peat pots, as seedlings sometimes react poorly to transplantation.
Don’t plant seedlings out until the soil and air have warmed up, such as when the nights begin to exceed 70 °F (21 °C). In my area, that’s often not until early July. It loves hot summers, tolerating temperatures of up to 122 °F (50 °C) without flinching, but the ideal is between 80 and 90 °F (26 to 32 °C) during the day and 70 to 80 °F (21 to 26 °C) at night. Depending on whether you choose an early or late eggplant, the harvest should start between 50 and 90 days after transplanting.
The eggplant being a nightshade (Solanaceae), take that into account when carrying out a rotation, avoiding planting it where there have been relatives like tomatoes, potatoes and peppers in the previous 4 years, as it shares several diseases and insect pests with them.
Plant your eggplants into soil rich in organic matter and minerals, well drained, but always fairly moist. Leave between 18 and 24 in (45 and 60 cm) between plants, depending on their eventual size. A good mulch will help reduce watering needs while preventing weeds and disease. You can also grow eggplants in pots.
In regions with long, hot summers, gardeners typically pinch the tip of the plant to stimulate better branching and therefore more flowers and more fruit, but this delays maturation and is not a good idea in regions with cool summers where you just have to settle for less fruit per plant.
Some larger eggplants will need staking, which I suggest doing on an as-needed basis.
Like other nightshades, eggplants need buzz pollination (vibratile pollination): a bee, in fact, usually a bumblebee, lands on the flower and starts to quiver rapidly, releasing the pollen which falls onto the stigma. The flower is self-fertile, with both male and female parts, and therefore even an isolated plant will produce fruit. If there are no bumblebees visiting your plant when it’s in bloom (honeybees don’t carry out buzz pollination), vibrate the flower with an electric toothbrush, preferably in the morning.
Harvest the fruit when it reaches an appropriate size and its final color (both will vary depending on the variety) and still appears shiny. This is well before full maturity and in fact you don’t want to wait for the fruit to mature, as fully mature fruits—they take on a dull appearance—may be bigger, but will be seedy and tough. To check whether a fruit is ready, lightly push your finger into its side. If the fruit gives slightly, then recovers immediately, the fruit is ready for picking. At this point, the flesh will still be juicy and the seeds will be few and tiny.
I’ll let you look up eggplant recipes: there are plenty to choose from!
Good luck with eggplants in your own garden!