Where do the souls of plant life go?

I feel really guilty but I killed our begonia ..on purpose too.

It was bought in honor of Shavuous, last spring, and was so beautiful full of life, flowers and real stunning. However, I do not have a green thumb and over time it slowly went down, losing most flowers and branches.

Eventually I brought it indoors to the living room where she became even more bewildering looking, because of a lack of sunlight especially at this time of year.

I figured since she is not happy, and taking up space and never going to flourish anyways like it did when I got it from the florist, so yes, I did the unspeakable…I put it outside in the bitter cold recently, and basically sentenced it to death.

I felt bad watching it die on the balcony, however I was wondering where the soul of dead plants go.