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

18 Sep 08, Liz (New Zealand - temperate climate)
Lisa, zucchini/courgettes behave like that when they are not fertilised. You could try using a soft paintbrush to do it by hand.
11 Nov 08, Liz (New Zealand - temperate climate)
Billie, and Bridget, your zucchini are dropping off because they are not pollinated. You can help pollination with a soft paintbrush if there are not many insects around.
12 Nov 08, Liz (New Zealand - temperate climate)
Billie, check behind the flowers. The ones with a miniature fruit are female. You can use pollen from the others. If all the flower stems are straight, you have male flowers only. That seems to happen when the weather is a bit cool as the plants start flowering.
10 Jan 09, hagges (New Zealand - temperate climate)
hi i grow a lot zucchini and mine to started to rot on vine so i increased calcuim nitrate to the plant and this fixed my problem (i make my own food hydroponic) hopw this helps
30 Jan 09, Liz (New Zealand - temperate climate)
Chrystal, I think you will find possible answers to your problem amongst the previous comments.
09 Feb 09, Christine Walker (New Zealand - temperate climate)
I have grown courgettes/ zuchinnis for a few years now and have never had a problem, but a freind of mine who has a farm out of town has just this year decided to grow her own vege. But she has had a problem with the above and they only grow to the size of your index finger. They are yellow and some die off, is this a plant species or is it something that she isnt doing. She assures me that they are getting plenty of water. The fruit looks healthy enough but is just really small Hope to hear from you very soon Cheers Christine
29 Jan 18, David Ching (New Zealand - temperate climate)
Try adding a good dose of lime
02 Dec 09, Liz (New Zealand - temperate climate)
Claire and Adam, The flower heads will drop off pollinated zucchini . Small zucchini rot because they are not pollinated. See earlier answers for info about hand pollination.
23 Jul 11, sartaz (Australia - cool/mountain climate)
how can i fix a broken zuchini stem. does anything work for it or i have to put it in the bin.
24 Jan 12, David (New Zealand - temperate climate)
No Zucchini flowers cause the rot as they absorb water. As soon as the zucchini starts to develop [3- 5cm] the flower needs to be plucked off to prevent rot. The same can be said for pumpkin, kumu kumu and butternut. Many more fruit will reach fruition especially with lots of manure to feed the soil nutrient sapping plants
Showing 1 - 10 of 61 comments

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