How To Grow Courgettes – Which?

Zucchini is a favorite this summer and produces a lot of fruit so you need few plants for most homes.

How to grow zucchini: month after month

The best zucchini variety

Which? Members can sign up now to see the full results and our Best Buy stock. If you are not a member, participate in which? for quick access.

How we try zucchini

We have grown 20 varieties of regular green, yellow, innovative or onion zucchini and selected new or previously untested varieties to grow alongside the Best Buy. We saw the seeds in the trays in a greenhouse in mid-May and then planted the top five plants of each variety in open ground. We waited until mid-June for a chance of frost when the transplant was over. The ripe fruit was picked twice a week during the high season and we recorded the number and weight of the fruit over 6 inches in height. We also evaluate the quality and characteristics of 10 fruit representatives of each variety. We tasted the fruit, both raw and after three minutes of cooking in the microwave, and evaluated each fruit for strength and taste, as well as the juice and texture of the skin, pulp and pulp.

When to sow

Zucchini is very sensitive to frost. Sow the seeds in late April or early May, no more than four weeks before they can be safely planted outdoors near you. Sow the large seeds one at a time in 7 cm pots a Best Buy compost to sow seeds in heated cooking tanks or on a warm window sill at about 20 ° C. For most homes, two plants produce more than enough fruit.

Take care of your plants


Dig a hole about 12 centimeters deep and in diameter. Fill it with a mixture of soil and compost or well-rotted fertilizer and leave a small mound. Wait until the risk of frost has passed before you recover in late May or early June. Then the young plants should have at least one large leaf.

Grown in containers

Some brands like ‘Sure Thing’ and ‘Patio Star’ are dense enough to grow in pots. Use a container that holds at least 10 liters and one Best Buy compost for containers mixed with one Best fertilizer fertilizer with controlled releaseCheck the compost every day to see if it feels dry and water it thoroughly if necessary. Feed the plants in containers with tomato food (rich in potassium) to promote fruit.

Protect from frost

Cover them with chips until they become strong.

to water

If the weather is dry, provide adequate water every 2 to 3 days. When it is hot, each plant can produce zucchini or even two a day if the roots are sufficiently moist.

How and when to harvest

Harvest in: July to September

Harvest the fruit when they are 10-15 cm long or even smaller to avoid overflowing. If the fruit is missing and growing too large, cut it off to encourage the plant to produce more fruit.

Common growth problems


Powdery mildew usually occurs in late summer or early autumn when the plants become steamless. You will first see white matter on the leaves that gradually gets worse before the leaves turn yellow and die.

Read more about powdery mildew.

Strangely colored leaves

Some species of zucchini, including Royal Flush, have silver spots with a smooth surface on the leaves. This is perfectly normal and requires no action.

Yellow-fruited varieties can also produce yellow leaves. This discourages commercial producers from cultivating them as they may look a little sick despite being perfectly healthy. Again, do not worry about cultivating them here.

Rotating fruit

The fruits begin to mature normally and change color at the end of flowering, although they are still rather small. The rot then spreads along the fruit to the stem.

Read more about rotting zucchini

No fruit

Sometimes the zucchini does not bear much fruit, especially in dry weather and in pots.

Read more about zucchini that does not produce fruit.


Zucchini, pumpkins and their families are susceptible to viral infections. Symptoms include jaundice, poor growth, mature growth and mosaic, round spots and leaf streaks, usually with very poor or no yield.

Read more about viruses.