I wrote this question to my brother-in-law because he is quite the gardener (well, he gives all the credit to his mother). At any rate:
“My potato plants grew up into beautiful bushes. Now they have fallen over and have flowers coming out. So, what does this mean? Close to having potatoes?”
Frank’s response: “Well the potatoes falling over is a sign that they have not been mounded enough. Not too much of a worry really unless they take away the light/space for other plants nearby. The flowers are normal. In fact when the first potatoes were brought to Europe by the Spanish, the people thought that they were to admire the flowers, nobody had told them about eating the bulbs!
The potatoes will actually still be quite small and not ripe yet. I wouldn’t think they can be harvested for a few more months yet. Usually a good sign is when the flowers have turned to seeds and the foliage starts to yellow and die-off. Then it is time to get the potatoes out. Only early varieties are harvested in summer, most will be harvested in September or even later.”