Zucchini vs. Eggplant: What’s the Difference? How Are They Similar?

Zucchini and eggplant have become vegetable garden staples over the years. With their delicious, highly nutritious, and versatile vegetables, it’s no wonder why. They are both easy to grow, and are favored by seasoned gardeners, and novices alike.

These delicious, fleshy vegetables look similar and are often used interchangeably in the kitchen. The plants also have very similar needs and growing conditions. Both can sometimes even face similar growth issues and attract the same pests. 

However, that’s where the similarities end. Zucchini and eggplants are ultimately quite different plants, sharing no relation and falling into very different classifications. Let’s take a deeper look at these two garden plants, and what makes each of them so unique.

Zucchini vs Eggplant

Specifications	Zucchini	Eggplant
Specifications Classification Scientific Name Hardiness Fruit Size Plant Size Sun Preference Soil Preference	Zucchini Squash Cucurbita pepo USDA 3-9 6-10 inches 3 feet wide Full sun Acidic, Well-draining	Eggplant Nightshade Solanum melongena USDA 4-10 5-12 inches 1-3 Feet Wide Full Sun Rich, Well-draining

Overview 

For starters, the main difference between zucchini and eggplant is in their scientific name and classification. Zucchini’s scientific name is Cucurbita pepo and it is classified as a squash. It also has a handful of other names, like courgette and marrow. Eggplant, on the other hand, is classified as a Nightshade, and its scientific name is Solanum melongena. Aubergine and guinea squash are other common names for eggplant. 

While eggplant is occasionally called a squash, it has no relation to zucchini or the rest of the squash family. There are also several varieties of eggplant often grown for their beauty rather than their fruits, making them wonderful ornamentals. A popular ornamental eggplant is the ‘Pumpkin on a Stick’. Its fruit resembles tiny pumpkins and makes a wonderful, dual-purpose fall decoration, perfect for Halloween and thanksgiving lovers. 

Zucchini, however, has less ornamental value. It is primarily grown for its delicious vegetables. Throughout history, zucchini has been cultivated and reproduced to give us the fruits we love. While zucchini has roots in Mesoamerica, the plant we eat today was cultivated in Italy in the early 1900s. It was only brought to the United States as late as the 1940s. 

Eggplant is native to China and India, cultivated for thousands of years. It entered the Americas in the 1500s, but it was not a popular plant. Belonging to the nightshade family, eggplant remained an unwanted plant for a long time. Eventually, it crept into the hearts of home gardeners everywhere and has become a vegetable garden staple.

Appearance 

Zucchini and eggplant grow on bushy, upright plants with thick leaves. Like the rest of its squash family, zucchini has a vining nature and large yellow flowers. Its glossy leaves are large, jagged, and very deeply indented. 

The most defining characteristic of zucchini is, of course, its vegetables, which tend to be a deep, dark green. They sometimes have white stripes that run along their length. Some varieties of zucchini are yellow, namely the Golden Zucchini, while others are shaped differently, like the Round Zucchini. 

While these plants look similar, if you take a closer look, you can easily tell them apart. Eggplant lacks the vining nature of zucchini, and its large leaves are slightly different too. They have lobes and are smooth, and ovate. Eggplant also sports gorgeous pendant-like violet flowers which give way to the delicious vegetables. These vegetables are large and oblong. 

Eggplants are typically dark purple, but they can sometimes be red, yellow, and white. They can also have stripes.

While eggplant has become a popular addition to the home garden, it’s important to note that it’s still a member of the nightshade family. Nightshade plants contain alkaloids that are extremely toxic to both humans and pets. Eggplant leaves, flowers, and immature fruit/vegetables contain these toxins, so keep them away from curious noses and paws. It’s also best to only consume eggplant when it’s ripe. 

Growing Conditions 

While these plants are very different, sharing different histories, families, and even appearances, they do share very similar growing conditions. Let’s take a look at what you can expect from each of these garden veggies when you decide to plant them in your garden.

Climate 

Zucchini and eggplant thrive in warmer temperatures, enjoying temperatures well above 65F. However, their optimal climates do differ slightly. 

Eggplant is hardy in USDA zones 4-10, tolerating temperatures as high as 90F. With that said, it does prefer more moderate humidity levels. Too much humidity causes the plant’s pollen to become sticky, preventing pollination. 

Zucchini, on the other hand, thrives in USDA zones 3-9 and prefers slightly cooler conditions. It grows best in temperatures between 65F and 75F, and unlike eggplant, zucchini doesn’t enjoy extremely hot conditions. Extreme heat tends to slow the growth of the plant and can ultimately reduce fruit production. Zucchini can also tolerate higher levels of humidity. 

Both zucchini and eggplant can’t stand the cold. Zucchini tends to stop growth all together when temperatures drop below 60F. Eggplant, however, can tolerate temperatures as low as 50F. Anything below that can have detrimental effects on the plant. One icy cold front or a small bout of frost can easily kill both zucchini and eggplants. 

Sunlight 

Zucchini and eggplants have a shared love of sunlight. They both thrive in areas that receive at least 6-8 hours of direct sunlight a day. Giving these plants as much light as possible ensures the production of delicious fruit throughout the growing season. Sunlight also decreases the chances of diseases, such as powdery mildew, which both plants are susceptible to. 

While they both share a love for the sun, zucchini can tolerate partial shade in extremely hot areas. As mentioned, extreme heat can cause stress for the plant. Eggplant, however, cannot tolerate any shade, no matter the climate. 

Soil and Fertilizer 

Perhaps the most common thing that zucchini and eggplant share is their soil needs. Both thrive in loamy, well-draining soil that is rich in organic matter. The correct soil is imperative for both these plants as they’re susceptible to rotting caused by overwatering and waterlogged soil.

You can easily improve your soil’s conditions by adding some compost or any other organic material. Coconut husk and river sand are great for improving the drainage and aeration of your soil. 

Zucchini enjoys soils that are on the acidic side, growing best in soils with a pH of around six. Eggplants, on the other hand, can grow in soil with either a slightly acidic or basic pH level. 

Zucchini and eggplant are hungry plants, needing fertilizer frequently. Zucchini requires a balanced fertilizer every month throughout the growing season. Eggplants have similar fertilizer needs, but they need a low nitrogen blend and should be fertilized once or twice a season. 

As a rule of thumb, avoid fertilizing fruits and vegetables with a high nitrogen fertilizer. Nitrogen stimulates foliage growth, resulting in leggy, bushy plants and low fruit yields. 

Water 

Eggplants and zucchini are as thirsty as they are hungry. They both need plenty of water to grow their delicious, fleshy vegetables. 

While both zucchini and eggplants need well-draining soil, it does need to be consistently moist. Soggy, waterlogged soil creates a breeding ground for several devasting diseases, like powdery mildew, root rot, and other fungal diseases. 

The correct watering methods will help prevent these diseases, and in the case of eggplants, prevent the growth of oddly shaped vegetables. It’s best to water both these plants slowly, deeply, and in the morning. This allows the water to penetrate the soil and reach as many roots as possible. Any excess water is also given the chance to evaporate throughout the day, which prevents pooling. Steer clear of overhead watering too, as it aids in the spread of diseases. 

Preventing the soil from becoming soggy is a tricky task, regardless of the method. But mulching around the base of the plant is a great way to keep the soil moist. It helps the soil retain as much water as possible, without it being too soggy. Mulch also comes in handy during extremely hot conditions, as it keeps the soil cool. 

Ease of Growth 

Zucchini, like the rest of its family, is notorious for its ease of growth. In the right conditions, they tend to grow quickly and vigorously.  

Eggplants, on the other hand, tend to be slightly trickier. Their light, water, and temperature requirements are critical for fruit production and overall plant health.  

Despite that, both plants are extremely rewarding, producing vegetables in less than two months, even when planted from seed.   

Unfortunately, both plants are suspectable to a variety of pests and diseases. Some are similar, while others are plant-specific. 

Diseases 

As mentioned, both zucchini and eggplant are susceptible to powdery mildew and root rot, but several other fungal diseases can ravage these plants. Bacterial wilt, bacterial leaf spot, and blossom end rot affect both zucchini and eggplants. Most of these diseases thrive and spread in constantly wet and moist conditions and when the plant’s soil is soggy and waterlogged. 

Eggplants are prone to a few other diseases, like verticillium wilt, southern blight, and Phomopsis blight. Southern blight attacks the roots and crown of the plant, eventually spreading to the soil. Both verticillium wilt and Phomopsis blight can kill eggplants, with the former attacking the stems and foliage of the plant. Phomopsis blight can cause spots on the leaves and stems of the plant too but mainly attacks the fruits.   

Zucchini Yellow Mosaic is a disease that only targets zucchini. It causes strange yellow patterns on the leaves and can result in necrotic fruits and leaves. 

These diseases can have devastating effects on both zucchini and eggplant plants, with some, like verticillium wilt, being near impossible to treat. In many cases, infected plants need to be uprooted and destroyed. With that said, good garden hygiene, the correct spacing, some pruning, and the right watering habits will prevent these diseases from taking root. 

Pests 

As part of the nightshade family, many pests tend to plague eggplants – namely, Colorado potato beetle, hornworms, and cutworms. Aphids and whiteflies are also common on both zucchini and its purple look-alike. 

Many of these pests can wreak havoc on your plants. However, most pests have the same weaknesses and can be prevented using very similar techniques. Avoid pesticides as they can result in inedible fruit and are bad for the environment. Instead, opt for organic methods that are food-safe. 

Each of these pests can easily be picked off your plants, squished between your fingers, or tossed into a jar of soapy water. Horticultural sprays, like neem oil, are a wonderful pesticide alternative that is completely natural, but they can burn the foliage if applied during the hottest part of the day. 

Final Thoughts 

Zucchini and eggplants are similar in a few ways, but they are not the same plants. They look different and have a few different needs. Eggplants can also be grown for their striking beauty, whereas zucchini’s main quality is its delicious squash. 

Their soil needs and love for the sun and water may make it seem like these would make a great pair in the garden. However, it’s best to keep them separate as their hungry natures will result in intense competition for nutrients and resources. 

In the kitchen, however, eggplant and zucchini are great together. They have very similar tastes and textures and are often used interchangeably in some dishes.