Gadenin日本語Get the appThe sowing date is set by the length of the season, not the calendar
Winter melon, also sold as wax gourd or ash gourd, wants 110 to 140 warm days from sowing to a fruit heavy enough to keep. That is a longer run than almost anything else in a home plot, and it is the reason most disappointing crops were disappointing before the seed ever went in. If you sow when the ground is merely workable, the plant spends three weeks sitting still and you lose those three weeks off the far end of the season, where they are worth the most.
Work backwards instead. Find your average first frost, subtract five months, and that is the week the soil needs to be warm, not the week you would like to be sowing. In a short summer that means starting under cover; in a long one it means sowing direct as soon as the ground holds heat overnight.
| Season length | Approach | Why |
|---|---|---|
| Five months of frost-free heat or more | Sow direct once soil holds 70F (21C) | No transplant check at all, the strongest roots |
| Four to five months | Start indoors three weeks early in large cells | Buys the weeks you do not have outdoors |
| Under four months | Start indoors and grow on black plastic mulch | Warm soil is the only way to make up the gap |
| Cool summers under 75F (24C) days | Grow one plant only, under cover if possible | Fruit will size but ripening runs late |
Soil temperature is the whole thing
Winter melon seed will not germinate below about 65F (18C) and simply rots in cold wet ground. At 70F (21C) it comes up in eight to ten days; at 85F (29C) it comes up in four. Push a soil thermometer four inches (10 cm) down and read it in the early morning, when the soil is at its coldest, rather than at the warm end of the afternoon.
There is no advantage whatsoever in beating the soil temperature. A plant sown a fortnight later into genuinely warm ground overtakes one sown early into cold ground within a month, and it does so without the stunted, hard-stemmed look that never quite grows out.
- Warm the ground first Lay black plastic or a dark mulch over the sowing station two weeks before you intend to sow. It lifts the top four inches (10 cm) by five to eight degrees Fahrenheit and holds the night temperature up as well.
- Soak the seed overnight The seed coat is hard and flat. Six to twelve hours in room-temperature water before sowing takes two or three days off germination and evens up the stand.
- Sow one inch deep Set the seed one inch (2.5 cm) deep, edge down rather than flat, and firm the soil over it. Shallower and it dries out, deeper and it exhausts itself pushing up.
- Sow three, keep one Put three seeds at each station and thin to the strongest at the second true leaf. Cut the losers off at ground level rather than pulling, so you do not tear the roots of the keeper.
How much room one plant actually needs
This crop is grown on the ground rather than up a trellis, because a single fruit can weigh twenty pounds (9 kg) or more and no home structure will hold three of them. That means the plant needs floor area, and gardeners consistently underestimate how much. A vine runs fifteen to twenty feet (4.5 to 6 m) and branches as it goes.
Give one plant a station and let it have the ground around it. Crowding is not just a matter of tangled vines: it holds humidity under the canopy, brings mildew forward by weeks, and leaves the developing fruit sitting in perpetually damp leaf litter.
| Setting | Spacing between plants | Row or bed spacing |
|---|---|---|
| Open ground, vines free to run | 5 to 6 feet (1.5 to 1.8 m) | 8 to 10 feet (2.4 to 3 m) |
| Hills of one plant each | 6 feet (1.8 m) between hills | Allow a walking path each side |
| Small plot, one plant only | Give it a 10 by 10 foot (3 by 3 m) square | Direct the runners back over themselves |
| Large container, 20 gallons plus | One plant, one container | Vines still need ground to run onto |
Do not try to train winter melon up a trellis the way you would a small melon. Even a well-made sling will not carry a twenty pound (9 kg) fruit for the eight weeks it takes to finish, and a fruit that falls is a fruit that will not store.
The seed bed itself
Winter melon is a heavy feeder with a deep root system, and it repays ground prepared before sowing far more than it repays feeding later. Dig a station a spade's depth wide and deep, work in two or three shovelfuls of well-rotted manure or mature compost, and refill so the surface sits an inch or two proud. That slight mound sheds water away from the crown, which is where rot starts.
Aim for a pH between 6.0 and 6.8. Ground that grew squash, cucumber or melon in the previous two years should be avoided, because the soil-borne wilts do not distinguish between them.
The first month, and what to write down
Young winter melon plants are slow and unimpressive for three or four weeks, then run hard. The job during those slow weeks is simply to keep them from checking: steady moisture, no cold nights on bare soil, and cutworm protection around the stem. A cloche or a floating cover until the first flowers appear is worth every minute it takes to put on.
Notes made now are what fix your sowing date for good. Guessing at it each spring is why the crop is late every third year.
- Soil temperature on the day you sowed Write the morning reading at four inches (10 cm), not the air temperature. After two seasons you will know the exact reading at which your ground is genuinely ready.
- Sowing date and emergence date The gap between them tells you whether the ground was warm enough. More than twelve days means you sowed too early on your soil.
- Where each station was Sketch the position of every plant. Next year the crop should not go back on the same ground, and by the time you are planning the next season you will not remember where it was.
- The date the vines began to run Note the day growth changes from slow to fast. That date, minus your sowing date, is the number that tells you how early you can safely push next season.