Vinca minor--commonly known as periwinkle--is an evergreen plant that is grown as a ground cover. Vinca minor has small blooms that flower in the spring and sometimes again in the fall. Vinca minor should not be confused with the annual flowering plant also known as vinca and periwinkle, but have the scientific name Catharanthus. Vinca minor grows in USDA zones 4 to 9 and are ideally planted in the spring.
Choose a location that is in partial shade, if possible. Vinca minor can also tolerate full sun and is often planted in sloped areas to help control erosion.
Weed the entire area, being sure to get the roots. You may be able to just use your hands to pull up them from the bottom. You can also use a hand-held weeding tool, which has three prongs that you dig under the weeds and then pull up, lifting the weeds and roots right out of the soil. If necessary, use a garden rake or tiller to loosen the soil which will make pulling weeds easier.
Amend the soil, if desired. Vinca minor is not picky about its soil conditions, however, you may want to till in a couple inches of humus (e.g., peat moss or compost) to the top 12 inches of soil to encourage faster and fuller growth.
Use a trowel to dig a hole(s) that is the same depth, but twice as wide as the container the vinca minor is currently planted. For instance, if your vinca minor is currently planted in a 3.5-inch-by-3.5-inch container--as many are--then dig a hole that is 3.5 inches deep and 7 inches wide. Multiple vinca minor are usually planted every 12 to 18 inches. However, if you want the area to be fully covered in just one year, then plant them 6 inches apart.
Take the vinca minor out of the container and set it in the hole.
Backfill the soil and use the palms of your hands to pack down the soil until it is firm. This will get rid of any air pockets, which can later cause root rot.
Water evenly to moisten the soil.
Mulch around the plants. This will help retain water and keep weeds at bay. When the vinca minor fills in over the years, you will not need to mulch.