How to grow zucchini

Getting started

Zucchini have large seeds that germinate readily. From mid-spring, you can sow directly in the ground in most areas. Plant two zucchini seeds per hole in small mounds of free-draining soil enriched with compost and organic fertiliser. The seeds are prone to rotting, so let the soil dry out between waterings until they germinate. When both seeds successfully germinate, thin out the weakest seedling. 

For a quick head start, buy established seedlings. If it’s still a bit chilly, or you can’t find room in the patch, start your plants in pots filled with premium potting mix. Balcony gardeners can grow a good zucchini crop in a container. Go for a big pot, at least 50cm wide, and place it in a sunny spot, protected from gusty winds. 

Zucchini vines trail as they mature and need a bit of room. Space plants at least 1m apart and plan where to direct their growth. They easily trail up and down a bed over a season. If you’re a bit tight on space, train them vertically on a trellis or tomato stake. Unlike cucumbers, they don’t have any tendrils, so you’ll need to tie the vines to their support with twine. They grow quickly, so check them every few days to keep everything in place.

Growing zucchini

Give the soil around the base of plants a deep soaking 2–3 times a week to keep them well hydrated, and maintain mulch to help retain moisture. Once a month or so, sprinkle around more organic fertiliser. Fruit production can start in as little as six weeks after sowing. If the fruit are not developing properly or rotting at the tips, it’s likely due to poor pollination, which is common. To maximise your return, get in the habit of hand pollinating. 

Once pollinated, zucchinis will expand quickly. I find they are at their best when they’re about 15cm long. Use a knife to cut them off at the base. Look out for powdery mildew – it can ruin plants if it gets out of control. Remove and destroy the worst-affected growth (usually older leaves) and spray the remaining foliage once every 10 days with an eco-fungicide. 

A few days of heavy rainfall during hot, humid periods can be seriously damaging to zucchini plants, particularly in tropical and subtropical areas. To help get your plants through these times, construct a simple frame over the vines – this could be just a few short stakes pushed into the ground – and toss over a sheet of clear plastic when dark, heavy clouds appear on the horizon. Remove the cover after rain.

Photo by iStock

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