You have to support them. If you are in FL then you are probably to late to grow peas. Better wait until the fall for a run with them. They don't like the hot weather or warm soil and they just won't grow. I use a fence to grow mine which also makes them easier to pick (no bending).
Summer gardening in FL is probably a lot like summer gardening in Southern California...well with a little less humidity.
We've grown super early varieties planted in April usually. It is required to shade them and keep them well mulched so they never dry out. Try planting them on a shaded wall by making a support trellis. You can a really inexpensive support using a PVC pipe frame and twine, which can also double as an irrigation system if setup correctly.
We normally take unused tomato cages, turn them upside down and make them into supports. Most sugar snap peas need about 5-8 feet of support.
I always like pushing the envelope as to what we can and can't grow and sometimes fail and sometimes succeed. Try it out. If they don't produce, then you know.