Gardening skill: flowers, herbs, vegetables and fruit!

After two weeks, I have finally evolved 6 of my 20 plants! I'm not sure how long evolution takes or how much fertilisation is required to make it occur, but it seemed to take forever! I used spinach and fish, mushrooms to fertilise the soil. I've found new plants too, so hopefully they grow! I had to fire my gardener though. He allowed 3 of my plants to die whilst my sim was at work - she's a scientist.