Do not try to grow grass under trees or in shady areas of your landscape.
Generally, lawns are seeded with a mix of Kentucky blue grass, fine fescue and rye grass. Each type contributes to the whole of the lawn, but none of them will grow well in full shade.
Instead, consider growing groundcover or making a mulch ring. Shade-loving sprawlers like vinca, pachysandra, sweet woodruff and ajuga can be bought in flats of 24 or 36 and spaced 6-12" apart. A mulch ring around the base of a tree helps retain moisture, limit soil erosion, improves aesthetics, and can even prevent lawn mower damage. Never spread mulch more than 4" thick—no mulch volcanos hugging your tree's trunk!
Research before you plant.
A masterful gardener chooses the right plant for the right place. Ask yourself a few questions before walking into a greenhouse or nursery: What kind of soil do I have? What is the sun exposure? Does the soil have good drainage? How much area do I want to cover? Then follow two simple landscape rules: plant in groups, or drifts, of three or more, and choose plants with nice foliage. Most flowering perennials have short blooming periods.
Avoid permanent mulch like landscaping fabric and rocks.
These may be efficient at reducing weeds for the first few years, but eventually soil and debris will accumulate and landscape fabric will have to be pulled up, and rock will have to be dug out to remove the weeds.
Plant landscape trees properly.
The most common and costly mistake in planting trees is planting too deep. You may even find that a young nursery tree is planted too deep in the pot that you bought it in. When transplanting, find the place where the roots start to spread out from the trunk, and place it at soil level.
Preparing your soil.
It is easy to add some organic matter like compost to give the roots a chance to spread and take hold.
Checking the roots when buying plants.
If the roots are white and have not a fully formed root ball, then the plant may not be healthy. Also check for thick, encircling roots. This plant has overgrown its container; tree roots can girdle the tree.
Avoid invasive plants.
Many plants can have invasive qualities and will be difficult to deal with in about two to three years. If you want to be cautious with your sweat investment, turn down that free plant from the neighbor, it is probably invasive.
Get a soil test!
Adding fertilizer to your lawn or garden without knowing your soil's current makeup is like taking a random product off the shelf at the drugstore for a headache. It's not likely to work the way you want it to, and it could even be dangerous. Don't spread, spray, or pour another dollar on your lawn without giving your soil a checkup!