How to Grow Courgettes (Zucchini): The Complete Beginner's Guide

Courgettes — known as zucchini in North America and much of the world — are one of the most generous vegetables you can grow. Once they get going, a single plant can produce dozens of fruits over the course of a summer. They're fast-growing, relatively pest-resistant, and perfectly suited to beginners.

This complete guide walks you through everything you need to know about how to grow courgettes from seed to harvest.

Why Grow Courgettes?

There are plenty of reasons courgettes deserve a spot in your garden:

Fast-growing: From seed to first harvest in around 60 days

Prolific producers: One plant can yield 20+ courgettes over a season

Versatile in the kitchen: Roasted, grilled, spiralised, stuffed, or baked into bread and cakes

Beginner-friendly: Few serious pest or disease problems compared to many other crops

Space-flexible: Grow in large containers as well as garden beds and raised beds

When to Sow Courgettes

Courgettes are frost-tender, so timing matters. Sowing too early leads to leggy seedlings sitting in small pots; sowing outdoors before the soil warms up causes seeds to rot.

Start indoors: 4–6 weeks before your last expected frost date (typically March–May in temperate climates)

Direct sow outdoors: Once soil temperature exceeds 15°C (59°F) and frost risk has passed

Harvest period: Approximately 8–12 weeks after sowing, depending on variety

In the Northern Hemisphere, late April to mid-May is the sweet spot for indoor sowing, with outdoor transplanting from late May onwards.

How to Sow Courgette Seeds

Growing courgettes from seed is straightforward if you follow a couple of key steps.

Step-by-Step Sowing

1. Fill 7.5 cm (3-inch) pots with good quality peat-free seed compost 2. Push one seed on its side, 2.5 cm (1 inch) deep — placing seeds on their side prevents water pooling in the seed's hollow and rotting 3. Water gently and place on a warm windowsill or in a propagator at 20–25°C (68–77°F) 4. Seeds germinate in 5–7 days

Caring for Seedlings

Once the seeds sprout:

Move to a bright location to prevent leggy, stretched growth

Keep the compost consistently moist but never waterlogged

If seedlings become rootbound before planting out, pot them up to a larger container

When the plant has 2–3 true leaves and is 10–15 cm (4–6 inches) tall, it's ready to harden off

Hardening Off

Before moving outside permanently, courgettes need to acclimatise to outdoor conditions. Skipping this step often leads to transplant shock or wilting.

How to harden off courgettes:

1. Place plants outside in a sheltered spot for 2–3 hours on a warm, calm day 2. Gradually increase outdoor time each day over 7–10 days 3. Bring indoors if overnight temperatures will drop below 10°C (50°F) 4. After 7–10 days of this routine, plants are ready for permanent outdoor planting

Planting Courgettes in the Ground

Spacing

Courgettes are big, bushy plants — give each one plenty of room:

Bush varieties: 90 cm (3 feet) apart

Trailing varieties: 1.2–1.5 m (4–5 feet) apart, or train up a strong support to save space

Soil Preparation

Courgettes are hungry plants. Before planting, prepare the soil by:

Digging in a generous amount of well-rotted compost or aged manure

Alternatively, plant directly on top of a compost heap — they thrive in rich, moisture-retentive soil

Adding a handful of slow-release balanced fertiliser to the planting hole

Position

Full sun is ideal; courgettes tolerate very light partial shade

Shelter from strong winds, which damage the large leaves

Near a water source — consistent watering is the single most important factor in courgette success

Growing Courgettes in Containers

No garden? Courgettes grow surprisingly well in large pots:

Use a container at least 45 cm (18 inches) in diameter and depth

Fill with peat-free multipurpose compost mixed with slow-release fertiliser granules

Raise the container on pot feet or bricks to improve drainage and prevent waterlogging

Water daily in hot weather — containers dry out far faster than garden beds

Feed every 7–10 days with a liquid tomato fertiliser once flowering begins

Watering and Feeding

Consistent moisture is the single most important factor when learning how to grow courgettes successfully.

Watering: Water deeply and regularly, especially during fruit set. Inconsistent watering causes blossom end rot or fruits that develop poorly

Feeding: Begin a weekly liquid feed (tomato fertiliser is ideal) once the first flowers appear

Mulching: Apply a 5–8 cm (2–3 inch) layer of organic mulch around plants to retain moisture, suppress weeds, and regulate soil temperature

Common Problems When Growing Courgettes

Powdery Mildew

White powdery coating on leaves is common in late summer, particularly in dry conditions.

Improve air circulation by removing a few lower leaves

Remove heavily affected leaves promptly

Spray foliage with a diluted milk solution (1 part milk to 9 parts water) as an organic preventative

Rotting Fruits

Small fruits rotting at the tip usually indicate poor pollination.

Hand-pollinate by using a small paintbrush to transfer pollen from male flowers (slender stems, no fruit behind) to female flowers (small fruit visible at the base)

Ensure plants are in a sunny, open position accessible to bees and other pollinators

Mosaic Virus

Mottled, distorted leaves with yellowing patches may indicate cucumber mosaic virus, spread by aphids.

Remove and destroy affected plants promptly — there is no cure

Control aphid populations early with companion plants like nasturtiums, which act as a sacrificial trap crop

When and How to Harvest Courgettes

The key to an abundant harvest is simple: pick frequently.

Harvest when fruits are 10–20 cm (4–8 inches) long for the best flavour and texture

Use a sharp knife to cut the stem cleanly — don't pull or twist

Check plants every 2–3 days in peak season; courgettes can double in size overnight

The more you pick, the more the plant produces — leaving fruits to grow large signals the plant to stop producing

Dealing with a Courgette Glut

Every courgette grower reaches the point where there are simply too many. When that moment comes:

Grill and freeze slices (blanch briefly first)

Make courgette soup, fritters, or chutney

Bake them into bread or muffins with lemon and herbs

Give them away to neighbours, friends, or local community fridges

Better yet, swap your surplus with other growers nearby. Locavori is a neighbourhood food-sharing platform connecting growers with the people around them. Whether you have a courgette mountain or you're looking for something different to add to your table, Locavori makes it easy to exchange homegrown produce with your community. Join the waiting list at locavori.app/register and be among the first to connect with local growers when the app launches.