Growing Zucchini, also Courgette/Marrow, Summer squash

Jan F M A M J J A S O N Dec
    S P P P            

(Best months for growing Zucchini in USA - Zone 5a regions)

S = Plant undercover in seed trays P = Sow seed

  • Grow in seed trays, and plant out in 4-6 weeks. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 70°F and 95°F. (Show °C/cm)
  • Space plants: 20 - 35 inches apart
  • Harvest in 6-9 weeks. Cut the fruit often to keep producing.
  • Compatible with (can grow beside): Corn, beans, nasturtiums, parsley, Silverbeet, Tomatoes
  • Avoid growing close to: Potatoes
  • a) seedlings
  • b) Six or seven weeks old
  • Zucchini flower

Plant into a slightly raised, well composted bed and mulch. Needs regular plentiful water. Produces large leaves with a spread of about 1.5m x 1.5m. Some varieties trail a bit but don't climb. The yellow (or gold) variety is more resistant to mould damage in humid areas and remains productive even when the leaves have mildew on them. The yellow varieties sometimes have yellow patches on their leaves but it is just colour not disease. If there are no bees around and the fruit are not setting well or die off after starting to grow, try picking a male flower (straight stem) and gently brushing pollen inside female flowers.

Blackjack is the most popular green variety. At the start, the plants produce mainly male flowers. The female ones start as the weather warms up and the plants grow. A spray with a 5gm/teasp Bicarbonate of Soda in 600ml/pint of water will help slow powdery mildew when it appears.

Culinary hints - cooking and eating Zucchini

Zucchini are best picked or cut off the stem at about 15cm / 6 inches.
Pick frequently to keep the plant producing new flowers.

Your comments and tips

24 Aug 20, Dave (USA - Zone 9b climate)
I cannot seem to get my zucchini to grow. The leaves keep wilting and dying off and so do the sprouts from below. We have a raised compost garden with tomatoes and bell peppers. It has been VERY hot this summer so perhaps I should be watering more? At what times should I water to help the plants the most? Thank you in advance.
25 Aug 20, Anon (USA - Zone 9b climate)
Take a look at the top of the page at the monthly planting guide, plant Feb Mar April. A lot of vegetables are seasonal so plant at the right time to get the best results. When watering, water low on the edge of the plant not above the flower and do it in the morning. A good watering 3 times a week.
27 Aug 20, Dave (USA - Zone 9b climate)
Thanks! I'll follow that guidance. I suppose I might have to replant in the Spring then too :)
23 Jul 20, Paul Bao (New Zealand - sub-tropical climate)
to pollinate it by hands
24 Jul 20, Anon (New Zealand - temperate climate)
Look up on the internet how to hand pollinate zucchini.
03 Jan 20, Steph (New Zealand - temperate climate)
Is it too late (January) to plant courgette plants
04 Jan 20, anon (New Zealand - temperate climate)
Check the monthly calendar at the top of the courgette page.
17 Jan 20, Owen Dawe (New Zealand - cool/mountain climate)
Planting seedlings ok.
23 Dec 19, Sonya McKerrow (New Zealand - temperate climate)
My courgettes get flowers on then only grow to about 10 cms flowers die and then courgette dies , has not done this other years don't know what is going on?
27 Dec 19, Anon (New Zealand - sub-tropical climate)
Sounds like you have no bees to pollinate the female flowers. Hand pollinate if you like. Look up the internet to find out how to do it.
Showing 1 - 10 of 316 comments

When is the last month to grow zucchini?

- Delores Victory

Please provide your email address if you are hoping for a reply


All comments are reviewed before displaying on the site, so your posting will not appear immediately

Gardenate App

Put Gardenate in your pocket. Get our app for iPhone, iPad or Android to add your own plants and record your plantings and harvests

Planting Reminders

Join our 60,000+ gardeners who already use Gardenate and subscribe to the free Gardenate planting reminders email newsletter.


Home | Vegetables and herbs to plant | Climate zones | About Gardenate | Contact us | Privacy Policy

This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. Gardenate is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
We cannot help if you are overrun by giant slugs.