When to plant zucchini – to enjoy a plentiful summer harvest

Once you know when to plant zucchini, you’ll be able to enjoy this deliciously versatile vegetable for months to come in your kitchen garden. 

Rich in vitamin B6, zucchini – or courgettes – are a staple vegetable for the summer months. This super versatile vegetable can be roasted, steamed, spiralled and even baked in a chocolate cake. 

Learning how to grow zucchini is really easy, so find out when to plant zucchini so you can enjoy an abundance of fresh courgettes throughout the summer months as part of your vegetable garden ideas. 

When to plant zucchini

'Zucchini loves heat, and plants thrive in the summertime. It's important to consider the length of the growing season in your hardiness zone, and make sure there's plenty of time for the fruit to develop before the arrival of the first frost, to avoid planting zucchini too late,' advises Alison Sidhu, executive editor of Gardener’s Path. 

As such, zucchini is best planted outdoors when night time temperatures 'are reliably above 55°F (13°C),' says Alison. This will be late spring or early summer in some regions. However, 'gardeners with short growing seasons can start seeds indoors when planning a greenhouse and transplant seedlings into the garden when it's warm enough,' she adds.

Zucchini are among the easiest vegetables to grow, so get the planting time right and you can't fail.

When should I start my zucchini?

You should start zucchini a good 4 to 6 months before the first first date in your region in order to guarantee a good crop, as these vegetables do not tolerate frost.

Jan Cashman from Cashman Nursery and Landscaping in Montana, explains that, 'since the vegetable matures in only 45-50 days, you can sow the seeds directly into the ground around June 1; we plant 2-3 seeds per hill. Remember that zucchini, like all squash plants, such as pumpkins, have no frost tolerance.' 

The exact month will of course depend on your USDA Hardiness Growing Zones. Given the right conditions, zucchini plants will produce a prolific harvest – one plant produces enough to feed a family of four – so are a good choice for small vegetable garden ideas.

'You can determine the length of the growing season in your area by finding the average first frost date in the fall, and counting backwards to last frost in the spring.' suggest Alison. If you find you have a shorter growing season, you 'can start seeds indoors and transplant seedlings into the garden when it's warm enough.'

If you grow zucchini in containers as part of your vegetable garden container ideas then it is easier to control the growing conditions and move the container indoors or outside depending on the temperature

How late in the year can you start zucchini?

How late in the year you can start zucchini depends on the growing season in the area where you live and the cultivar you are growing. Zucchini has a growing season of about 35-55 days, depending on the variety you chose to grow. Check the number of days to maturity for your selected cultivar, and plan accordingly so that you can harvest the crop before the first frost date.

Remember that zucchini is not frost tolerant so plant it at the latest 4-6 weeks before the first known frost date in your area to ensure a crop.

How cold can zucchini plants tolerate?

Zucchinis are warm loving plants so can not tolerate it too cold and need full sun in order to grow well and to produce a good crop. 

They require an outdoor temperature of about 70°F (21°C) and should only be planted outside once night time temperatures are consistently above 55°F. 

If you need to start off your courgette plants under cover, 'always harden off your plant for approximately a week before planting them out, and check the last frost date in your zone before planting out as they are tender and likely will not survive even a mild frost,' says Nick Welsh from Seed Craft.

'If you’re due a late frost, then place a cloche over the plants at night for extra safety,' he adds, which is among the ways to protect plants from frost. 

How long does it take for zucchini to grow? 

On average it takes zucchinis only 45 to 50 days to grow, advises Jan Cashman, but this does depend on the variety you choose to grow. 

It’s important to check how long the variety you are growing takes to mature as this will determine when to plant zucchini. Also try to plant alongside zucchini companion plants to boost the chances of a good crop.

Some varieties of zucchini require just 40 days to mature, while others may not be ready to harvest for 70 days. Zucchini growth may be slowed if the plant is affected by fungi or disease. A good way to spot this is if the zucchini leaves turn white.

Now that you know when to plant zucchini, you will be able to enjoy a homegrown glut of this delicious and versatile vegetable.