Here are a couple of good examples solutions of small scale 'patio trees' that will serve the purposes intended while keeping maintenance time and costs lower; a Drake Elm (Ulmas parvafolia) or a Crape Myrtle (Lagerstroemia indica). These trees have smaller leaves which tend to disperse easily in a breeze and generally do not have large branches dropping regularly like their larger cousins. While these trees still provide shade for the average home or patio space, these smaller 'patio scale' trees are more human scale trees to spaces that are near or adjacent to homes or buildings. They also have the added attraction of an interesting bark pattern and summer blooms respectively, without the aggravation of the large leaves and dropped branches of their larger 'park-scale' tree cousins. Choosing the right tree for the right space can be as easy as understanding the growth habit of the tree which should be labeled on the tree when you are purchasing it. Ask the nursery professional for help in selecting the right tree and remember to ask what the tree's final height and width will be when picking, so you can select wisely and eliminate the excessive maintenance from too large a tree for your property.