How to Grow Honeydew Melon

The melon that will not tell you when it is ready.

A honeydew is a different melon from a rockmelon or cantaloupe. Those are the netted ones, and they ripen earlier and tell you when they are ready. A honeydew has smooth skin, takes longer, and gives you almost no signal at all. Everything below follows from that.

When to sow

Sow from late spring, October and November, once the soil has warmed properly. Honeydews need more heat and a longer run than most New Zealand summers give easily, so this is a crop for Northland, Auckland, the Bay of Plenty and the warm sheltered pockets further south. Elsewhere grow them in a tunnel house and pick an early variety.

Giving it what it wants

• Heat, and a lot of it. This is not a crop to rush into cold soil. Seed sown into ground below 18 degrees rots rather than germinates, and a fortnight's patience saves a replanting.
• Full sun and room. Vines run two to three metres. Plant on mounds about 90 cm apart, two or three plants to a mound.
• Rich soil, then restraint. Dig in plenty of compost before planting, then go easy on nitrogen afterwards. Fed hard, a melon makes magnificent leaves and poor fruit.
• Consistent water while the fruit swells, then ease off as they approach ripeness. Heavy watering late dilutes the sugars and splits the skin, which is the most common way a good melon is spoiled in the last fortnight.
• Mulch underneath. Straw or a board under each developing fruit keeps it off wet soil and stops the underside rotting.

Pollination, and why the first flowers set nothing

Melons carry separate male and female flowers on the same plant. The males open first, sometimes a week or two ahead, so early flowers dropping without fruit is normal rather than a fault. The females are the ones with a tiny melon already behind the petals.

If bees are scarce, hand pollinate in the morning: pick a male flower, strip the petals, and brush the pollen onto the centre of a female. It takes ten seconds and it is the difference between a crop and a vine.

Telling when one is ripe, which is the whole skill

A rockmelon slips: the stem separates cleanly when the fruit is ready. A honeydew does not. It will hang on the vine long after it is ripe, and waiting for it to let go gives you a mushy, fermenting melon. Use these instead, and look for at least three of them:

• The skin turns from green-white to creamy yellow-white. This is the most reliable single sign.
• The surface loses its gloss and takes on a faint waxy or slightly tacky feel.
• The blossom end gives a little under thumb pressure, opposite the stem.
• It smells sweet at the blossom end. No smell means not yet.
• The tendril nearest the fruit dries and browns. Useful as a supporting sign rather than on its own.

Cut the stem with secateurs, leaving a short stub. Do not pull, because tearing the stem out opens the fruit to rot and it will not keep.

Unlike a rockmelon, a honeydew does keep improving a little off the vine, so one picked slightly early and left on the bench for a few days is recoverable. One picked late is not.

What goes wrong

• Plenty of flowers, no fruit. Either only males so far, or no pollinators. Wait a week, then hand pollinate.
• Fruit rotting underneath. Sitting on damp soil. Put a board or straw under each one.
• Bland or watery flesh. Too much water late, not enough sun, or picked early.
• Split skins. A heavy soak after a dry spell. Water steadily rather than in bursts.
• Powdery mildew on the leaves. Common late in the season. It usually arrives after the fruit has set and does little harm by then.

See also: Honeydew melon in the Plant Library for sowing months tuned to your region, and the netted melons, which ripen earlier and do tell you when they are ready.