The growing season is upon us and courgettes, or zucchini as they are also known, are a firm favourite with gardeners.
They are easy to grow, nutritious, and produce a good yield.
While courgettes are typically known for their elongated shape, the appearance of round courgettes can leave gardeners both puzzled and fascinated.
Other shapes can also occur such as swelling at one end, or a bend in the middle.
In this article we look at the science, genetics, and environmental factors that can cause this to happen.
So if you have ever wondered “why are my courgettes round?”
Then read on to find out!
Genetics at Play: Courgette DNA
The shape of a courgette is largely determined by its genetic makeup.
Round courgettes are often the result of a genetic mutation that affects the elongation process.
Traditional courgettes elongate as they grow, resulting in their familiar long shape.
However, when a mutation affects the genes responsible for this elongation, the courgette can take on a round form instead.
It’s important to note that these genetic mutations are a natural part of plant biology and can occur spontaneously.
These mutations can result from a variety of factors, including exposure to environmental stresses, radiation, or even genetic recombination during pollination.
In some cases, these mutations may have no discernible cause and are simply a result of the inherent variability of plant genetics.
Environmental Influences: The Role of Growing Conditions
While genetics play a significant role in shaping courgettes, environmental conditions can also contribute to the development of differently shaped courgettes.
Factors such as temperature, humidity, and nutrient availability can impact how a courgette grows and develops.
Some courgettes can become bulbous at one end, or bend in the middle!
- Temperature Fluctuations: Extreme temperature fluctuations can stress plants and disrupt their normal growth patterns. Inconsistent temperature conditions during courgette development may lead to irregular growth and the formation of round fruits.
- Pollination Issues: Courgettes require proper pollination for the development of healthy fruits. If there is a lack of pollinators or if pollination is incomplete, it can result in irregularly shaped courgettes, including round ones.
- Nutrient Imbalances: Inadequate or imbalanced nutrient availability in the soil can affect fruit development. Nutrient deficiencies can lead to stunted growth and misshapen fruits, including round courgettes.
- Water Stress: Insufficient or erratic watering practices can impact courgette development. Drought stress can disrupt normal growth processes and contribute to the formation of round fruits.
Hybridisation and Cross-Pollination
The world of gardening often involves experimentation and the creation of hybrid plants through intentional cross-pollination.
If you’re growing multiple varieties of courgettes in close proximity, there’s a possibility that cross-pollination may occur, leading to unexpected fruit shapes.
This can happen if pollen from one variety is carried to the flowers of another variety, resulting in unique characteristics in the offspring.
If you’ve intentionally or accidentally crossed different courgette varieties, it’s not uncommon to observe variations in fruit shape among the resulting plants.
This can lead to the appearance of round courgettes alongside more traditional ones.
If there are limited pollinators like bees, this can sometimes result in small or malformed fruits which do not elongate properly, again creating a more rounded shape.
To increase pollinators in your garden or allotment, plant lots of flowering plants that attract bees and other insects.
You can also hand pollinate courgettes by gently touching the pollen from one flower and then brushing it onto the open flower of another vine.
Cultural Practices: The Human Element
As gardeners, our practices and interventions can also influence the growth and development of our plants, including the shape of courgettes.
Pruning, training, and overall plant care can play a role in determining the final appearance of the fruits.
- Pruning Techniques: Improper pruning can disrupt the natural growth patterns of courgette plants. Overzealous pruning or trimming can lead to round courgettes as the plant attempts to compensate for the removed foliage.
- Plant Stress: Intense stress, whether from harsh weather conditions, disease, or pests, can impact courgette growth. The plant’s response to stress may result in altered fruit shapes.
Intentional Selection
Some gardeners deliberately select and save seeds from unique or round courgettes to create their own strains.
Over time, this selective breeding can lead to a higher prevalence of round fruits.
This practice over many years has now produced many different round varieties of courgette.
Some examples are: ‘Ola Redonda’, ‘Tondo Chiaro di Nizza’ and the brilliantly named ‘Hand Grenade’ courgettes!
Final Thoughts
In the end, the development of round courgettes is an interesting blend of genetics, environment, and human influence.
While they may seem unusual, these round courgettes remind us of the intricate dance between nature and nurture that takes place in our gardens.
They are just as tasty as long courgettes, and can provide an interesting looking meal – round courgettes can be stuffed like peppers or squashes.
As you continue your gardening journey, embrace the surprises that each season brings, and consider the fascinating stories that can unfold within the heart of your vegetable patch.
Other brilliant fruit and vegetables to grow include Cavolo Nero and Chillies.