Pea plants are very good at dancing around looking for something to cling onto with their tendrils. To get them growing upwards quickly (and thus preventing slug damage) you can give them a simple support made from bamboo and chicken wire.
To construct your pea support is very easy. Simply use pliers to cut the chicken wire to the right length (50-60cm high is fine, and the length depends on how many peas…allow approx 10cm per pea plant). Then, tie a bamboo cane to each end using garden twine, or by wrapping the chicken wire around the bamboo (wear gloves if you want to avoid scratched fingers!) Then just jam the bamboo canes into the ground and plant your pea plants at the base of the chicken wire at 10cm intervals. Depending on the length of the chicken wire, you may wish to prod an extra bamboo cane into the ground halfway along and tie in the chicken wire.
Once you’ve planted your peas, gently nudge the tendrils to the chicken wire until they latch on. Doing this will get them growing in the right direction nice and quickly.
The alternative to this is to find some nice twiggy twigs (i.e not smooth like bamboo canes, but something a bit, well, twiggy!) that are approximately 40-50cm long and use them as stakes. This always looks nice, but it all depends on how many twigs you have lying around!