Zucchini/Courgette (Cucurbita pepo)
& Other Summer Squash
GROWING SUMMARY​
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Onions are frost hardy and germinate best between
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Timing:
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Direct Seeding
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Growing Seedlings
Germination temperature -
Bed Preparation
Raised beds
On the flat -
Plant Spacing
Germination temperature -
Irrigation
Germination temperature -
Pests and Diseases
Germination temperature -
Harvesting
November – January depending on variety & location
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GROWING SUMMARY​
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Quick and easy to grow frost tender annual .
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Can be sown straight into the ground as soon as the soil temperature is over 20°C. Plant two seeds 20mm deep, 500mm apart with a row spacing of at least 1metre. Zucchinis must be allowed plenty of space.
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In colder areas get a head start by planting seeds in 100 mm pots. Transplant into the ground carefully (cucurbits don't enjoy rood disturbance) and cover the plants with a low tunnel of green house plastic or frost cloth. Remove the covers at flowering to allow pollinating insects good access.
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Thin to one plant per spot once there are 3-4 leaves.
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Zucchini need full sun, fertile, well drained soil with a pH of about 6.5. They benefit from plenty of nitrogen to produce large healthy leaves.
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Drip irrigation will minimise weeds and fungal problems.
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Spray with an organic fungicide to prevent mildew and be on the look out for leaf eating beetles that need to be squashed by hand.
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Pick the fruit regularly and small and if you want a break in harvesting pick off the flowers - much better for the plants than allowing the fruit to grow into a monster. Throw the flowers into the compost or stuff them and deep fry in tempura batter if you want a treat.
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Zucchini and squash are at their best early in the season. You can do a second planting early summer but by the end of summer even later plantings seccumb to downy mildew.
VARIETIES​
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Choose varieties carefully, particularly if you are a home gardener. At their peak all the summer squash over produce so a few plants of quality cultivars are essential if you are not going to be overwhelmed by fruit.
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Classic Green Varieties. The most common commercial types. Very productive and mild tasting. Can be a bit watery and tasteless if allowed to grow too big. Good sized flowers for cooking.
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Cocozelle. Classic Italian striped variety with firm texture and a sweet nutty taste.
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Lebanese Zucchini. Similar to Cocozelle but pale skinned. The skin marks easily so handle gently after picking.
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Romanesco. A ribbed, speckled Italian heirloom with very dense flesh. Not as productive as the smooth skinned varieties but really tasty even when allowed to grow large. Very large vine so they need space.
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Yellow Varieties. Similar to the green types but a great colour addition to salads.
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Yellow Crookneck, a special heirloom with an odd shape and knobbly skin. The warts are little flavour bombs - one of the best yellow varieties.
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Button Squash. Similar to green and yellow zucchini just a different shape.
More Information
Over Production
Gardeners and cooks have a love hate relationship with Zucchini. At the end of winter when everyone is thoroughly tired of cabbage and kale they make such a welcome early start to the summer pick. They are quick growing and the more unusual varieties are flavourful and versatile. However there is such a variety to choose from it is very easy to grow too many plants and become completely overwhelmed to the point where you neglect to pick them resulting in oversized fruit and diseased, ugly, unproductive plants. The trick is to save garden space by just putting in a few plants and to check the plants daily removing all harvestable sized fruit. They store really well in the fridge till you have enough to cook, you will not get tired of them and the plants will reward you till the end of summer.
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Pollination
All the cucurbits produce both male and female flowers. They are easy to tell apart. The male flowers have a thin stem and the female flowers sit on top of a miniature fruit. Early in the morning open flowers are visited by bees, wasps and other insects who carry the pollen from the male to the female flowers. So although covers are great to protect and warm the plants early in the season they interfere with this process when the plants start to flower. It is common to have the odd malformed and/or shrivelled fruits early in the season due to poor pollination. Monoecious (produce purely male and purely female flowers) need particular care if you want to save seed. Your green zucchini will very happily cross with a yellow button squash with unpredictable results. Plant breeders bag up the flowers and hand pollinate to get the varies they are after.
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A Biased Plant Choice .....
Commercial Grower - concentrate on modern green hybrid varieties, Cocozelles and a yellow zucchini.
Home Gardener - grow Cocozelle, yellow crookneck and a couple of Romaneso plants.
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