Ferns are another option that's often found growing naturally in heavily shaded forests.
Do you have trouble with grass underneath large shade trees in your landscape? Or no grass at all? This is a common problem for those of us fortunate enough to have such large shade trees.
One option for this shady situation is to plant the area with a shade-tolerant ground cover or even landscape it with shrubs, annuals and perennials that thrive in shade. If you want to stick with the concept or look of a grass, a great substitute is to plant the area with a low-growing ground cover.
Some of your options for covering larger areas with ground covers include monkey grass, creeping lily turf, coral bells, Asian jasmine, English ivy, and Japanese ardisia. Another choice is vinca (Vinca minor), and it has flowers.
Ferns are another option that's often found growing naturally in heavily shaded forests. Choices include maidenhair fern, lady fern, oak fern and resurrection fern. Some non-native options are autumn fern, holly ferns, leather leaf fern, and sword fern with others also being available.
Other plants to consider are black snakeroot, also known as black cohosh, caladiums, wild ginger and ligularia. Plants like caladiums, gingers and ligularia can be readily found in local nurseries while the more-native plants sadly are not as available.
Be aware that when planting around trees it is very important to remember the root system of the tree itself. You do not want to damage a large tree's root system. When possible, try to avoid cutting any roots larger than 1 inch in diameter. This can be done more easily by using a gardening fork rather than a shovel to turn the soil under the tree.
Remember if you pile too much soil around the trunk and root area, the trunk has a tendency to decay. If you need to bring in extra soil to amend or create a bed, use as little as possible. We like to suggest no more than 2 to 4 inches deep. If you intend to cover a large area of the tree's root system extending out well beyond the reach of the branches, limit it to a 2-inch thickness.
If you find that planting is more than you want to do and the grass-barren area has become too unsightly, a final and relatively cheap and easy solution is to simply mulch the area. Leaves, pine straw or other mulching materials can be applied 4 to 6 inches deep under a tree where grass no longer grows well. Mulch has many benefits. It helps retain moisture for the roots of the trees, slows the growth and sometimes prevents weeds, and adds organic matter to the soil as it decomposes. It also looks very attractive and natural. As the years go by and the mulch settles, you can simply add more mulch to maintain a 4-inch to 6-inch depth.