Cucamelons grow easily from seed, and the method is not unlike growing cucumbers. They like full sun to partial shade, and require rich, well-draining soil amended with compost.
If you’re in zones 3 to 6, you’ll want to start seeds indoors about six weeks before your last spring frost. The seeds are tiny, so only sow them about 1/4 inch deep and keep the soil consistently moist so the seeds don’t dry out. They will germinate in 7 to 14 days.
If you have the space, I recommend sowing seeds in 4-inch pots and thinning to the strongest seedling per pot, which helps them develop good root systems and minimizes transplant shock.
You might even want to insert a chopstick—like the disposable ones you get with takeout food—so the seedlings have something to climb. This keeps them from getting tangled together in your seed starting trays.
Once all risk of frost has passed, harden off the young plants and move them into the garden, giving them 12 inches of spacing.