Growing Zucchini, also Courgette/Marrow, Summer squash

Cucurbita pepo : Cucurbitaceae / the gourd family

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

(Best months for growing Zucchini in New Zealand - cool/mountain regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • 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 21°C and 35°C. (Show °F/in)
  • Space plants: 50 - 90 cm 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 1.5 m x 1.5 m. 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 5 gm/teaspoon Bicarbonate of Soda in 600 ml/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 15 cm / 6 inches.
Pick frequently to keep the plant producing new flowers.

Your comments and tips

10 Feb 24, paul swan (New Zealand - temperate climate)
why does the young growing marrow/zucchini go brown or rot on the flower end of the vegetable before maturity.
14 Mar 24, Harry (New Zealand - temperate climate)
Hi Paul, blossom end rot can also be associated with water issues and/or calcium issues. Sometimes the plant suffers because water is too unreliably available, i.e. it dries out between adequate waterings. The growing zucchini will be
15 Feb 24, Liz (New Zealand - sub-tropical climate)
Rot in young flowers usually means that they have not been pollinated. You might have to try hand pollination
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 61 comments

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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. GardenGrow 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.
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