poorly sweetpeas

It could be the weather or watering regime, have you tried cutting them back this sometimes revives poor plants and you may have a pleasant suprise with the result. What have you got to lose do let us know what happens.

may be over-watering, let them dry out quite a bit - then give a good nitrogen feed, they may buck up a bit then!

Sweetpeas really resent root disturbance. Champion growers plant seeds in a cardboard loo roll tube so that they can plant out the whole thing without disturbing the sweetpea roots. Could this be the answer? In any event I hope your sweetpeas have only suffered a temporary blip and are romping away now.