I would be remiss if I didn't mention such an easy to grow, fruit bearing shrub. Though blackberries are actually made up of several canes that branch out to create fruit bearing limbs, they are still categorized as shrubs for whatever reason.
Moving on from my confusion about why blackberries are even labeled shrubs; blackberry bushes definitely fall under the category of "will grow itself as long as you give it water".
To give you an even better idea of how durable blackberry bushes are, I recently took some blackberry cuttings from one of my own blackberry bushes to propagate new bushes. In about a week, some of these blackberry cuttings had already started growing roots. For anyone who has ever tried propagating by cuttings before, you will know from experience that this is an extremely short amount of time to wait for roots to form for any plant. This is just an example of how willing blackberries are to grow and how they can make excellent starter plants to your indoor fruit plant collection.