Tulips are among the most popular of all the spring-flowering bulbs. With over 100 species of tulips and hundreds of hybrids available, gardeners can have their landscapes filled with a rainbow of color each spring. However, bare patches of ground can be left after the tulips are spent. Ground cover can fill in these spots and also provide a carpet underneath your tulips.
Do not choose very dense, thick, woody (i.e., have woody stems as found on shrubs) ground cover. Your tulips will not be able to grow up through it. For example, steer clear of junipers, such as "Wiltonii," that are great for suppressing weeds but will also suppress the growth of spring-flowering bulbs such as tulips.
Choose low-growing ground covers such as "Creeping Jenny" and various sedums, such as "Angelina." Different types of thyme are also good choices. These types of ground covers do not have thick woody stems, making it easier for the tulips to grow up through them.
Plant directly over the tulips. There is no need to worry about planting ground cover directly on top of your tulips. The tulips will find their way to the surface. Simply dig about a 1-inch trough where you want you ground cover and place the ground cover in the trough. Cover with soil.
Space your ground cover about 12-18 inches apart. Most ground cover has a 12-18-inch spread; therefore, if you are planting more than one pot of ground cover, you should space the plants at least this far apart. As they grow, they will fill in the gaps.