Walks in the neighborhood take me past lots of flowering trees, shrubs and grasses. One such shrub in a public park is full of Gardenia bushes that bloom at this time (June) of the year. After they bloom they sprout new shoots from the cuttings of which you can start new Gardenia plants. Last year we started about a dozen shoots in started pots, most of which rooted. We then transplanted the shoots in various places around the house. By the time winter rolled around they were strong enough to survive. In early spring they began to revive and started new leaf buds, but to my everlasting surprise flower buds appeared about a month ago as well. I wasn't expecting flowers for a few years if at all. Now we have these sensuously beautiful flowers in our own backyard.
Another flowering plant I picked up from an empty lot is a succulent that produces symmetrical purple pink flowers that I simply dropped and covered with a little dirt. It has taken and is spreading and also producing flowers the first year after transplanting.