There's nothing quite like a bit of shade on a hot summer's day. It would be even nicer if there was some healthy grass growing there. Growing grass in the shade can be difficult, but it can be done. Find the best grass seeds and alternatives to grass for shady areas.
The area under tree canopies allows little sun and water to get through to lawn grass. Grass also has a very tough time competing with tree roots for nutrients from the soil. One option is to get a tree professional to remove some lower tree limbs or thin the crowns of the trees to let more light in. There's still no guarantee that grass will get established.
Shade-tolerant grass varieties are available, but remember the key word is tolerant — no grass is likely to grow well for long in deep shade. As far as grass types for shade, St. Augustine is a good warm-season variety; red fescue or Chewings fescue are good cool-season types. Sun / shade seed blends are also available. Plant warm-season grasses in early spring; cool-season grasses in fall.
When grass seed is planted, provide a lot of water to get the root system established. Make sure you mow it as high as possible. Some types will require regular reseeding. High-nitrogen fertilizer promotes blade growth, which is not really what you want. Look for a fertilizer with a higher concentration of phosphorus to promote root growth. Before undertaking any major fertilizer program, get a soil test kit and follow the recommendations.
If you're looking for alternatives for shade, you may want to consider planting some shade-loving perennials or groundcovers. Hosta, periwinkle, Asian jasmine, star jasmine, baby tears, ajuga, cast iron plant, dichondra, sweet Woodruff, liriope or pachysandra do well and look good in the shade.
Another alternative is to add a mulch bed to your shady spot, but be careful not to pile the mulch too deep around tree trunks.