how to grow vegetables & fruits on hard surfaces?

[hajafri]

my sweet potato plants got blue flowers now................................................. should i dig for the fruit? is it indication of fruit inside? when should i dig ? 1 week before i saw the flowers.......................................... and how to dig? from the roots or only where the flowers are? asif

[Izhar]

Dig after 6 months minimum... dig from roots...

[hajafri]

ok thanks and whats about peanut plants they got 2 yellow flowers each plant when they should be dig? asif

[Izhar]

8-10 months