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

09 Dec 07, Kirsten (Unknown climate)
I am having trouble with rot on my zucchini as soon as the vegetable starts to develop. Do you have any ideas.
21 Jan 08, Jac (Unknown climate)
I am having the same problem as Kirsten with rotting ends on my zucchini - what do I do about it?
07 Feb 08, Ket (Unknown climate)
So am I, I am looking into it and hopefully have an answer. My zucchini's leaves are going all white and I have never had this happen. I have grown zucchini's the size of pumpkins and this season they are really bad........
07 Feb 08, Chris (Unknown climate)
Leaves going white sounds like powdery mildew, probably due to all the wet. You could try a spray of dilute (1 to 9) skim milk and water (see RHNZ website:, or a commercial spray.
17 Feb 08, Richo (Unknown climate)
The Zucchini rot at the end because they are not fetilised properly. You need to get the flowers to germinate and you can do this by hand. Try this page it explains how and why I planted 3 plants this year and with out a letter of a lie I had three months of production and at least 20kg of zucchini.
18 Feb 08, Rachel (Unknown climate)
Lime your soil. A couple of handfuls of lime will definately fix the problem. Works with tomatoes if they get brown bottoms too. It's apparently the magnesium. Happy harvesting
04 Mar 08, saini (Unknown climate)
This is the first time I have grown zucchini every thing was fine can anyone tell me what will be the average life of the plant. thanks
04 Apr 08, Kel (Australia - cool/mountain climate)
Can you please tell me is a MARROW just an overgrown Zucchini ? I have always belived that they come from the same family but are different vegetables.
12 Apr 08, DC (Unknown climate)
In Australia, marrow most often means an overgrown zucchini but in other parts of the world "marrow" might be used for almost any member of the squash family.
01 May 08, Kel (Unknown climate)
thanks for the handy hint DC - Kel
Showing 1 - 10 of 356 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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