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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.

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

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.
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.
10 Nov 19, Craig Hawkins (Australia - temperate climate)
Is blackjack the best variety
09 Oct 19, Sue (New Zealand - temperate climate)
Is there any way to tell which direction a courgette plant will grow in when planting a seedling - they tend to sprawl in one direction and its always a punt which way that will be. Sometimes they end up growing into other plants. My plant has 3 leaves on it and a smaller one coming similar to the one in your photo top of page. Thanks.
14 Oct 19, anon (New Zealand - sub-tropical climate)
Happens quite a bit here. The wind will blow the plant over, so that is the direction it grows in mainly.
06 Oct 19, Alex (Australia - temperate climate)
Hi I'm from Melbourne vic. I've had 3 attempts of growing zucchini black jack and so far no success, first attempt the plants we're taken with no trace 2nd they got eaten down to the stem this is my 3rd attempt I put tree guards and snail pellets around them also growing a nasturtium nearby but the leave are getting munched on. What can I do these are only young plants?
01 Jan 20, Catherine (Australia - sub-tropical climate)
I had the same problem - I cut off the bottoms of soda bottles, threw away the lids and placed the bottle over the plant, pushing it into the soil enough to stop it from blowing over. I then simply removed the bottle when the plant was looking a little cramped - worked a treat!
07 Oct 19, anon (Australia - sub-tropical climate)
An extreme method would be to make a wood frame about 50cm high and cover with 30% shade cloth. OR put stakes in the ground and use shade cloth or bird netting as a fence. I have 2m x 2m x .5m frame with veggie netting on and around it. Only problem the netting disintergated from flapping on the wood frame. I will replace with 30% shade cloth soon. Or make an arch with plastic pipe or chicken netting and cover with shade cloth. Look around the yard for things you could use.
Showing 1 - 10 of 308 comments

I am having trouble with my courgette. It starts off green and healthy, then the end gradually turns yellow which spreads up the the vegetable then it goes soft and shrivels up and dies. Do you know what's wrong? Thanks

- Nikki

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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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