Scabiosa, or pincushion flower, is an old world native, long grown for its showy, colorful flowers. This low, mat forming plant can be annual, biennial or perennial, depending on the particular species and variety. Gardeners are often dismayed when these plants perish over the winter. Most often, the problem is not the cold temperatures, but the wrong location and incorrect growing conditions. Scabiosa is a relatively short lived plant, but with proper care, can be coaxed to stay in your garden for many years.
Choose a location that will get as much sun as possible throughout the winter to plant your scabiosa. Gentle, well-drained, south facing slopes are ideal. Avoid areas that will be shaded by buildings or evergreen trees.
Amend the soil with equal parts fine gravel and sharp builder’s sand to increase drainage. The main cause of these plants’ winter decline is too much moisture, so the soil where they are planted must have excellent drainage.
Add soil amendments, such as dolomite lime or wood ash, to make your soil slightly alkaline, if it is neutral or acid. If you are unsure of your soil pH, you can easily test it with an inexpensive kit available at most garden or hardware stores. Scabiosa grows best at a pH between 7 and 8.5, so add enough dolomite lime or wood ash to adjust soil pH within that range.