Like bonsai, a root trim every two or three years will help to limit the overall size of the tree.Read more: How to Grow Ultra Dwarf Fruit Trees | Garden Guides <a href="http://www.gardenguides.com/85473-grow-ultra-dwarf-fruit-trees.html#ixzz307suOwFpStandard:">http://www.gardenguides.com/85473-grow-ultra-dwarf-fruit-trees.html#ixzz307suOwFpStandard:</a> That huge old apple tree in Grandpa's back yard is a standard, the only choice of size before the smaller hybrids were developed.