Lightly spade an area under the weeping cherry tree 20 feet in diameter.
Apply plant-food granules to the area. Rake them in, following the label directions.
Choose a ground-cover plant, like wild violets, lilies of the valley, yellow archangel or creeping phlox.
Plant the ground cover 12 inches from the trunk of the tree, moving around the tree. Place plants every 12 to 18 inches.
Move 18 inches away from the first planted row of ground-cover plants and plant another row. Continue until the last row of plants is 18 inches from the edge of the planting area.
Plant hostas, Virginia bluebells or wild ginger along the area's border to create depth in the flowerbed.
Apply a layer of mulch 2 inches deep around the newly planted perennials to retain moisture in the soil.