Home Garden

How to grow watermelons

Your guide to planting tips and harvesting

There’s no better way to cool down on a warm summer’s day than with a juicy watermelon. Watermelons grow on vines which unfortunately only those with a bit of space will be able to grow them. Here’s everything you need to know to grow your own watermelon at home. 

When it comes to melons we’re spoilt for choice in Australia. Most of the watermelons you’ll find in the supermarket are locally grown and we can access them year-round. 

Climate

Watermelons love warmth so they’ll thrive in warmer seasons and climates and are happy in sandy soil with a pH of 6.5 to 7.5. They don’t like frost and seeds won’t germinate in temperatures below 15°C. 

Aspect

Watermelons need at least six hours of full sun per day but in very hot conditions their leaves will burn so make sure there is some shade from the midday sun.  

watermelon

How to plant

Watermelons grow on vines so need a lot of room to spread and grow. One vine can grow up to six metres long and each vine will produce between two and four melons. You can grow watermelons from seeds or from a seedling.

Before you even think about planting watermelons you need to think of a couple of things. 

  1. Have you got enough room and space for the vines to crawl? 
  2. Is your soil full of nutrients? Watermelons are heavy feeders so it’s a good idea to fertilise or place some compost down before planting. 

Hint: when choosing which variety you’ll grow at home the smaller the better as they won’t take as long to grow. 

How to grow watermelon

Sow three to four seeds 1cm deep in the soil and leave to grow for a couple of weeks, once they start to grow pick the strongest plant. Water your vines every couple of days and fertilise each fortnight. 

watermelon

Around two weeks after planting your vines should begin to flower. The smaller male flowers will grow first followed by the female flowers. Bees should be able to pollinate your flowers for you, but if you don’t have any bees around you can give them a helping hand. Watch this video. 

How to harvest watermelon

Generally speaking, it takes around 30 days for fruit to fully mature. You’ll know that it is time to harvest your watermelons when the underside turns from yellow to green and when you spot a brown tendril on the watermelon. To harvest simply cut the fruit off the vine and enjoy. 

Plant Care & Troubleshooting

Mildew

Watermelons are prone to powdery mildew in humid conditions. To stop mildew from growing make a concoction of one part milk to nine parts water and spray the vine each week. 

watermelon

Pests

Pests love to nibble on watermelon vines so make sure you keep a natural bug killer handy.

Companion plants

The best companion plants for watermelons are corn which helps protect them from the harsh sun. Marigolds and oregano also make great companion plants as they help keep pests away. 

You might also like:

How to grow sweet potatoes

Everything you need to know about growing carrots at home

Your go-to guide to homegrown cucumbers

Related stories