I would just thin them...remove the less hardy of the bunch. Try to have only 4 to 5 plants AT MOST in that space. (Only 2 to 3 is better.) You can certainly train the squash up a bit, however trying to put in a trellis at this stage that is sturdy enough to accomodate heavy squash might damage the roots of the plants that are growing. Perhaps you could constuct a trellis behind the raised bed and weave some of the twining stems into it. Ultimately, each plant, if given adequate space, will produce more than enough squash for you and your family. With them crowded as they are, they might not produce much at all. So just yank out the less hardy specimens and you'll have plenty of squash.

In the future, try to stay with at 2 square feet for each squash plant, in my opinion.

Patty

Try this method of horizontal growing after thinning the plants out as Patty suggested:

Drive 6' long, 1" bamboo stakes into each corner of the bed. Set them about 12" into the soil and pack'em tight. "Connect" them by lashing shorter bamboo stakes from corner to corner at about 4' tall. You've essentially framed a box over the plants.

Run string from the cross stakes to the base of the saved plants. Tie the bottom part of the string to a 12" piece of bamboo and stake into the ground. This won't disturb the roots enough to disturb fruiting.

Train the vines up the string. Because the plants will be oriented outwards toward the side of the bed picking will be easy and you won't have plants on top of plants which can lead to not so pleasant fungus.

Sound somewhat familiar? Any of us who worked the tobacco fields in CT remember .... LOL

It'll be a bit of work, but tell any available kids that you're building a teepee kind of thing and you'll have plenty of help.

Martie