Busy Lizzies are generally very easy plants to grow. Normally they will tolerate most conditions. They do like a moist soil & will often grow in full sunshine but are happy to grow in light shade as well.

You don't give any further symptoms so it is difficult to give a better answer. Are they getting too dry or too wet? Both conditions can kill them. They may be infected with Red Spider Mite, a tiny, almost invisible pest that sucks the sap from the leaves & leave webbing on the plants if you get a serious infestation. In a dry, hot summer, like this year's, they are very predominant. They can weaken plants so that they die. There's not a lot you can do about these mites, there are few chemicals available nowadays but trying to increase humidity around the plants can help. You can achieve this with a mulch around the plants & watering frequently.

thanks they r still dying!

Sorry to hear that! :-( The plants I have on my balcony are not looking very good either. But they have produced a lot of seedlings that are springing up in some of the other pots I have on the balcony. If you have seedlings, easily recognised because of their glossy bright green seed leaves, you could lift them & put them into small pots & grow them on.

I shall lift some of mine to grow on in the house during the winter.