I have moved many a plant around at this time of year,
Jennyfer..and never lost any..as long as you remember to water them really well first,and prepare your new planting hole beforehand...make sure you take a big enough root ball with your plant..and don't do it in the heat of the day..maybe in the evening whn it's cooler..plenty of water in the new hole too ..good luck..:o)

I'm with bloomer. I do it all the time, and as long as the plants has good enough rootball it should be fine. I also find it helps in the hotter days to reduce the leafy growth to aid re establishing the plant in it's new home. Especially things like Geraniums and Geums etc.

We have some plants to move but I will wait until this heatwave?????? is over.

Thanks all of you :) I will definitely bear in mind the not in the heat of the day comments, I hadn't really thought so much about that. I'm glad I will be able to make some changes now - it is so frustrating wanting to move things but having to sit back and wait :P

And, Jennyfer, you will need to keep your moved plants well watered, particularly during dry spells of more than a day or so, until late autumn. The only reason autumn is a good time is because there's usually much cooler weather and its much damper, meaning the plant copes much better.

Ah cool thanks, I will do that :)
+ does all this mean that I can divide said plants as well? Several of the ones I want to move are desperate for it.

Well if you want to risk it now, you can, but you'll probably lose a lot of the topgrowth, and watering will be even more essential.

I do it all the time too, i was advised not to move Phlox in June but I did it anyway, they are both now in their new place flowering away! :)

Okay :) Thanks for all the help.... I will try to avoid dividing unless I'm feeling really desperate :P