I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
You may be overwating the flowers. If the soil doesn't drain very well the soil can get too soggy and the roots will start to die from lack of oxygen. For an area with part day sun some flowers to consider include begonias, wishbone flower, petunias, Salvia 'Mystic Spires', and plumbago to name a few.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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