• Shade trees don't have to kill your grass.Kevin Trageser/Photodisc/Getty Images
  
  The combination of shade trees and grass isn't always an easy one to make work. Tree roots compete with grass for nutrients, and tree canopies block light that grass needs for photosynthesis. If you've planted Kentucky bluegrass or fine fescue, you have a better chance of having a lush, shaded lawn. When planting shade trees, go for trees with deep-reaching root systems. Avoid trees like willow, sycamore, elm and maple, because their roots are shallow and spread great horizontal distances.
  
  

Pin Oak

• Plant pin oak for its deep-reaching root system and narrow leaves that offer shade while still allowing light to filter through. Pin oak can reach a height of 40 to 50 feet, but is slow to get there. It has a narrow, but open shape that won't shade enormous areas of lawn. Rake up pin oak leaves when they fall, because they're tough and can take a long time to decompose.
  
  

Thornless Honey Locust

• Try thornless honey locust for feathery, dappled shade. It's a fast grower, at a rate of 4 to 5 feet per year. Delicate branches are tipped with lacy foliage that lets light through. In fall, leaves shrivel and barely need to be raked. Deep roots find moisture far below grass roots, making it one of the best trees for planting with grass.
  
  

Yellow Poplar

• Plant yellow poplar (also called tulip tree) if your yard is bigger than an acre. Yellow poplar, trees grow at a rate of 2 to 3 feet per year, reaching heights of 60 to 100 feet, with deep, central tap roots that keep them firmly anchored. Prune lower branches as the tree grows, and give it ample space from other plantings. This will help the sidelight of morning and evening sun reach the grass beneath.
  
  

European Alder

• According to the University of Wisconsin, European alder roots often grow down past the water table, making it one of the deepest-rooting trees available. It can grow to height of 60 to 70 feet, and flourishes in many soil types. Alder's broad, open shape offers a good amount of shade while still allowing light to filter through its branches and reach grass. Alder leaves also return more nitrogen to the soil than many other types of trees.