Crochet help - joining granny squares

[IDoLikeARainbow]

Arrggh

I'm trying to join some granny squares with a slip stitch, despite trying my best to keep my tension loose they are a bit 'gathered'.

Do you think I need to frog the joins and start again or will I be able to block it flat?

Thanks

pin it out on your ironing board and steam it with your iron then let it cool on its own, move it and do the next section. looks great btw!

Thank you, I've got another couple of rounds to do on the border but didn't want to do that if I needed to start again!
Will try blocking it. Thanks

Looks great and think it will flatten out fine. What's the pattern? I'm looking for a granny square pattern that doesn't involve changing colours all the time

You need to use a bigger size hook when you join... it stops it getting all rucked up. I always go one size larger

I'm doing one massive granny square but mine looks a bit boring. Its just double crochet shell stitch. I love your pattern. id like to know what it is too!

Thanks All, it has flattened out after a bit of pinning but will try the using a larger hook to join next time, thanks Hooksville.

Pattern is based on this pattern by Purl Soho although my squares are actually these and I only did one round of the contrasting border.