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 S S S S
T T T             T T T
P P               P P P

(Best months for growing Zucchini in Australia - sub-tropical regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • P = Sow seed
  • 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 1.5m 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

20 Oct 22, Pete (Australia - temperate climate)
My Zucchinis sprouted about 10 days ago. They have grown new leaves and the whole plant is yellow. Zucchinis are planted in heavily composted ground. Anyone with suggestions to get them to green up? TIA. Cheers Pete
25 Oct 22, Anonymous (Australia - sub-tropical climate)
If the compost is not completely broken down to compost/humas it will take the nitrogen first and the plant will not receive much. It could take 1-3 months for the compost/nitrogen to become available for the plants. Could try watering in some fertiliser around the plants although too much and you end up with big plants.
22 Aug 22, Jason (Australia - temperate climate)
I found for pumpkins and zucchini I need to have several plants growing and need to hand pollinate from one plant to another. I wait until a male flower is ready on one and a female flower is ready on the other, usually in the morning.
14 May 22, marco (Australia - tropical climate)
hi i live on the gold coast qld .i am harvesting my crop now .we are experiencing a lot of rain .some of my crop rotting at end . plaridel if you pollinate yourself you get better results .
29 Jun 22, marco (Australia - sub-tropical climate)
hi i live on the gold coast .its 29.06.2022 i am still getting the zucchini slow growing struggling ,yet going ok. i grow on a mesh screen now it gets more sun and takes less room .hand pollinate .bees are coming back in the garden yet still a bit cold for them .
15 Apr 22, Plaridel Logan (Australia - tropical climate)
I also failed 2x that started from yellowing followed by falling off flowers and died. A friend of mine who succeeded in getting healthy fruits told me she planted in a generous amount of soil mix of compost cocopeat and carbonized rice hull and planted in companion of string beans. I'm just waiting for my seed order so I can apply the same approach and hope with God's grace for a positive result.
08 Apr 22, marco (Australia - tropical climate)
hi i live on the gold coast .i have planted new zucchini a few weeks ago they are looking good ,some flower stems are sprouting now .so we will see if it works out .zucchini are great !! i get one a week or more in the good times ,i stuff them full anything they are healthy and filling .
20 Mar 22, Graham (Australia - temperate climate)
I have grown trombone zucchinnis this year in amongst butternut pumpkins. Can anyone enlighten me as to whether they will cross pollinate.
26 Mar 22, Anonymous (Australia - sub-tropical climate)
yes they can.
22 Mar 22, Celeste Archer (Canada - Zone 7b Mild Temperate climate)
I think that your trombone will be ready to harvest in about 60 days (from seedling to harvest date - called a summer squash) -- and I think that butternut squash (pumpkins) take closer to 120 days (from seedling to harvest date - called a winter squash) ==> my best guess is they will not be flowering at the same time; so no cross pollination will occur. If for some reason you staggered the planting so they were to flower at the same time; my best guess is YES they can cross pollinate -- squash seems to cross pollinate with other squash easily....however, this is just a guess based on what I know about other squash.
Showing 1 - 10 of 251 comments

We have some healthy looking Zucchini Plants growing but unfortunately they are only producing female flowers. Not much good for fertilization. Can anyone give me a reason or solution to this problem ?

- Robert Perkins

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