I successfully trained both pumpkins and sugar baby up a fence last year. However:

The watermelons are tougher. Most of that is being able to tell when to harvest (especially when they're hanging in a sling) and the stems will NOT support the weight if your sling fails. Checking on them also presents issues unless there is 0 tension on the stem. It's possible, you just need to be extra careful. I did the same with cantaloupes with success.

The pumpkins (regular old orange) I grew just hung by their stems with no problem/support, but they're much more durable. In fact, the last two survived the tropical storm we had, intact.

One last note: watch out for the rogues. You'll have a few that feel growing inside the fence space is a good idea. If you don't keep them away until they're too big to fit, you'll either end up with permanent dents or Siamese twins with the fence permanently in place, lol.

Also - pumpkins and watermelons take a LONG time. If you aren't expecting frost, don't worry about replanting. Pumpkins will keep for months if properly stored. Watermelons, well, chances are you'll end up impatient and harvest too early, lol.

Cheers,

-Rathosaf

I'm not sure about regular pumpkins, but with giant pumpkins, the 3rd true leaf will show you which direction the vine will travel. Plant it with the 3rd leaf facing the direction you want the vine to go. Nancy

Just let em sprawl in the grass, just make sure you put some straw or cardboard or something under the pumpkins and melons so they don't rot on the ground. My melons are usually ripe to pick when the tendril closest to the melon shrivels up and browns. I've tried slinging them before but it's a pain to keep up with and the vines usually wind up getting pinched and tangled from the weight no matter how well I support the melons. Ideally they just like to sprawl and run :)

I've done them in containers. Not super productive, but I got some fruit. That way you can put them in a sunny spot in the lawn without a lot of extra prep work.

Thanks for all the answers - I always love this site for all the excellent info and advice!

I'm thinking I'll do a combination of training the pumpkins on the fence and let both (watermelon and pumpkins) go into the grass along side. Just have to hope can keep grass down and no damage to the plants when/if mowing and weed eating!

With the pumpkins, they say 110-120 days for harvest. So with the ones I "jumped the gun" on, I'd figure they'll be ready by August. Not sure I can keep them stored that long so will start some new ones and should time out right (if adding right, it'd be early - mid September). Maybe I'll train the current on the fence and let the newly planted seeds go into the grass...

Again thanks everyone for the info, ideas, and tips!