I live in East Vancouver with a south facing backyard. I have blueberries, blackberries, garlic, Swiss chard, kale, St. John's Wort, lavender, oregano, thyme, wormwood, and lemon verbena growing with a plot of grass. What kind of fruit tree(s) can I grow best here with the least disease? I do not want my current garden riddled with diseases. I was hoping to plant a peach, apple and/or cherry tree. Do I need male female pairs, two breeds of each, etc? If I have to deal with diseases or high maintenance to prevent diseases I will not grow fruit trees. I believe in companion planting and NO harmful chemicals. I do not want trees that will have invasive roots as I live in a 100 year old house with questionable underground pipes. Lastly, I do not want trees that are too tall that they overshadow my other plants.