It’s juicy, it’s refreshing and it’s one of the great delights on a hot day. PHIL DUDMAN explains how to grow your own watermelon, even when you don’t have masses of space
There are few experiences that are more satisfying than sinking one’s face deep into a big chunk of sweet, juicy watermelon on a hot summer’s day. If it’s a watermelon you’ve grown yourself, the satisfaction level goes right off the scale!
This guarantee of gratification is what I used to spark my youngest son’s interest in growing food. When he was in primary school, we planted some seed together in our garden, then pollinated the flowers by hand and nurtured the vine right through to harvest. Every day after school he ran out into the garden to check on its progress. I can still recall his expression of unadulterated joy as we cracked the first one open.
Another great thing about growing watermelons is the interesting range of varieties available. You may be thinking, “I don’t have enough space in my garden for a watermelon vine.” Well, the good news is, there are some compact varieties, and with a little training, you can contain a vine in a 2–3m² space or grow one up a trellis.
growing & harvesting
Watermelons need 3–4 months of warm to hot conditions to produce a crop. October is ideal for sowing and planting in most areas, except for the tropics (sow April to July, so crops mature before the wet begins). If you’re in a cold area where the season is short, consider growing early-cropping varieties. Try getting seeds started this month in small pots in a warm, sunny spot, or buy seedlings to plant out in November, when the soil warms.
Lots of sun is needed, and a well-drained soil enriched with plenty of compost and well-rotted manure, plus a little organic fertiliser. A pH of 6–7 is ideal. If yours is below 6, add some lime. Lime also supplies calcium required for fruit development. If your pH is within range, add gypsum for calcium.
Create a raised mound of soil to assist drainage, then shape a shallow depression at the top to catch and direct water. Space the centre of the mounds 1.5–2m apart. Direct sowing is best. Plant 3–4 seeds at a depth of 2–3cm in each mound, then pick out the weakest seedlings, allowing the strongest one to grow. If you’re planting seedlings, be gentle because they dislike root disturbance.
Developing vines need plenty of moisture, but you can back off as fruits reach maturity. Mulch around the base to conserve moisture. Once vines start to creep along the ground, give a light application of organic fertiliser. Repeat when fruits start forming.
Get to know the difference between male and female flowers. The female ones have a tiny fruit at their base. If you see female flowers but the
fruit aren’t forming, it means they aren’t getting pollinated. If this happens, you can pollinate them yourself by simply picking some male flowers and dabbing their pollen onto the female flowers.
I used to allow vines to ramble in among young shrubs in new garden beds. I’ve also contained a vine in a 3m x 1.2m vegie bed by pinching out a few of the tips and redirecting any rogue runners so they stay in their allotted space. My favourite space-saving method is training vines over an A-frame of heavy-duty steel mesh. This works brilliantly as long as you provide some sort of support for the heavy fruit, such as a length of fabric tied to the frame. Check out the video on our Facebook page to see how I do it (facebook. com/ABCGardeningAustraliamagazine).
There are a few methods to determine when a watermelon is ripe, including checking the underside, which should be cream or yellow in colour, and tapping it – it should make a hollow sound. I find the most reliable indicator is the tiny tendril near the fruit. When this is totally brown and dried up, the watermelon is ready to eat.