Although the first four cucamelon seeds all germinated they never grew beyond a couple of leaves and eventually withered (probably overwatered, it seems to be my downfall). Undeterred I planted a couple more seeds and waited. They germinated to much warmer temperatures and they have really taken off in the last week or so, enough that I built them little tripods to climb up. They have cute little tendrils that curl and grip. It says you can plant them out, but I am thinking wait a while to avoid the upcoming thunder storms. I hardly care if they fruit now, I am just so pleased they grew.
Stay safe. Be kind. Persist in the face of disappointment.