Enjoy your own harvest of watermelons and spanspek – it’s so easy!

No other fruits announce summer like watermelon and spanspek. With our guide to growing them yourself, you can enjoy your own harvest from these rewarding, sun-loving vines.

Thanks to their sweet flesh, melons are sought-after summer fruits. Both spanspek and watermelon are members of the cucumber – Cucurbitaceae – family, which includes pumpkin, squash, marrows and even loofahs. Watermelon has not always been sweet. Before cultivation of the thousandplus modern varieties, which differ in sweetness and colour (red, yellow, pink and white), the wild watermelon, or tsamma, was an essential water source for travellers in arid regions.

1 PICK THE RIGHT SPOT

Let’s start with the bad news: it is too late to sow your own now. Spring – once the soil temperature is constantly over 17ºC – is the best time to get spanspek and watermelon into the ground. Varieties differ slightly, but on average it will take 12 weeks for your plants to grow from seed and produce fruit. SUN At least six or more hours of sunlight are needed per day. The northern sides of walls will warm up earlier in the season, making it possible to sow them in earlier. SPACE The vines are surprisingly slight for the size of the fruit that they bear. If you have limited space, it’s best to grow them along edges such as walls or fences to avoid having to step on the brittle stems and risk damaging them. SOW Sow the seeds directly into the ground where you’d like them to grow. If your soil is not yet developed, dig holes of about 30cm3 in size. Fill them with water and allow it to soak in. Mix the soil from the hole with an equal amount of compost, a handful of bone meal and, if you suspect a calcium deficiency, some crushed eggshell. You should end up with extra material – use this to form a little mound over the hole. Sow three seeds of the same variety 1cm-2cm deep in the centre of the mound.

The seeds should take about five days to germinate. Once sown, it is advisable to use an empty two-litre cooldrink bottle with the base cut off and the cap removed as a mini hothouse over the mound. This will speed up germination and protect the seedlings from snails and cutworm.

Once the seedlings have three true leaves each, select the strongest seedling and cut the other weaker seedlings at the base. It seems harsh, but by allowing weak plants to grow you make your garden a magnet for all kinds of pests.

2 KEEP THE PLANTS HAPPY

These fast-growing vines are enthusiastic climbers; they have strong tendrils that enable them to climb trellises, fences or pergolas with ease. Their stems strengthen as the fruit grow in size and weight.

Relatively small yellow flowers will start to appear around the fourth week after germination. The first flowers that appear are exclusively male. Don’t be alarmed when they start dropping off. The flowers that follow have male and female parts, and the potential to develop into fruit after being pollinated properly. SUPPORT If you are growing one of the larger varieties, it’s a good idea to add a bit more support when the fruit start to swell – anything that will allow air and water movement, such as orange bags, shade cloth or bird netting. WATER Watermelon, as the name suggests, needs lots of water. Drip irrigation is best, as overhead irrigation, especially when applied late in the day, can encourage fungal diseases. It’s normal for leaves to wilt during the heat of the day – they should recover during the night. If they don’t, you’ll need to increase the amount or frequency of watering. When fruit are the right size and start to ripen, it is important to water less in order to concentrate the sugars. POLLINATION This is very important – improper pollination will lead to small, misshapen or aborted fruit. Ensure that there are many other flowering plants, such as borage, as well as “bug hotels” in the garden to attract pollinators and beneficial insects to the garden. PROBLEMS Watering early in the day is a good countermeasure against fungal disease. If you spot anything wrong with the leaves, chances are it’s something fungal. If this is the case, spray the leaves with a dilution of peroxide: one teaspoon of 30% peroxide (obtainable from any pharmacy) per litre of water.

3 IT’S HARVEST TIME!

When a fruit is about the size of a tennis ball, lift it gently and place a layer of straw, cardboard or pine needles underneath it to prevent rot.

Many people have trouble deciding when fruit are at their optimal ripeness and ready for harvesting. If you harvest too early the fruit will be bland; harvest too late and they may taste mealy or start to rot. WATERMELON These signs indicate ripeness: the colour of the skin underneath the fruit will change from white to a creamy yellow; the small tendril closest to the fruit will dry out; and, of course, we all know it should sound hollow when thumped. SPANSPEK If the fruit separates from the vine easily when you pick it up, it’s ready. If it doesn’t come off, lay it back down and try again tomorrow.

Remember, the fruit won’t ripen all at once but in close succession. Stored in a cool place, they’ll remain fresh for up to two weeks after harvest.