Growing Zucchini, also Courgette/Marrow, Summer squash

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

11 Mar 21, Hettie (South Africa - Summer rainfall climate)
when do I start seedlings. I am new to gardening veggies but as a pensioner it keeps me busy. I am teaching my grandchildren both 8 years old to grow veggies. My 2 daughters are single parents.
14 Mar 21, colleen (USA - Zone 10b climate)
If you mean when do you start zucchini seedlings, specifically, the chart says you should start them in September in your zone.
12 Mar 21, Anonymous (South Africa - Summer rainfall climate)
Work out your climate zone from the Blue Tab across the top of the page. Then go to the vegie you want to grow to find out when to plant the seeds. Use the monthly calendar for when to plant seeds or seedlings. With little seeds like cabbage it may be better to buy seedlings. Do some research on the internet about growing vegies -
19 Dec 20, Genevieve (Australia - temperate climate)
I have been growing zucchini for past couple of years. Vines grow big ang healthy, the fruit grow to a couple of inches, and then begin to yellow, wither and die. I am not sure if it's lack of pollination or something else. I garden organically and while I have not planted flowers next to zucchinis there are flowers not too far away. Any clues, I'd love to hear. Thank you, in advance.
22 Dec 20, Anon (Australia - temperate climate)
Probably no bees in your garden/area. Check your flowers between 7-11am in the morning to see if any bees. If no bees consider growing plants/flowers that attract bees, flies, birds. Zucchinis are easy to hand pollinate in the morning. You should have noticed that some flowers have a little zucchini - female and some don't - male. Break off the male flower, pull off the flower part and rub the pollen onto the female flower. Google how to do it if unsure.
22 Dec 20, Margaret Phillips (Australia - sub-tropical climate)
Hi, I have exactly the same problem! I live in a sub tropics.Originally had two zucchini plants ,but just as I was getting excited about having grown some great zucchini,it up and died on me. I use a sprinkler system and was recently told zucchini’s don’t like to get wet leaves. Melons have also been a failure. Any tips welcome. Thanks Marg
01 Dec 20, adrian (Australia - sub-tropical climate)
what is the best way to cook and eat zucchini's.
08 Dec 20, Gabriella Hont (Australia - temperate climate)
Try spiralizing them and use zucchini instead of spaghetti with your favourite pasta sauce.
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.
Showing 1 - 10 of 325 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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