Light
Rose campion does very well in partial sun, or in full sun. It can have a tendency to dry out during a hot summer, so consider placing it in a spot with morning sun as opposed to afternoon sun. It will usually not bloom in full shade if it happens to re-seed there, so you can relocate any volunteers to a sunnier spot.
Soil
While it is not too fussy about soil, like most plants the rose campion does best in soil that is well drained. Avoid planting in wet areas, as this may cause the roots to rot.
Water
Rose campion is fairly drought tolerant once established, so is a good addition to a dry garden area. It has no special watering needs. Water according to your usual schedule in the cottage or perennial garden. If it gets a lot of bright sun during a heat wave, and shows signs of drooping or burning, you may have to give it a bit of extra water.
Temperature and Humidity
Rose campion is hardy to Zone 5, and may not make it through especially cold winters. However, if you’re in a reliable Zone 5 it should re-seed normally for you. Too much moisture in soil is not good for rose campion, but humid summers in temperate climates shouldn’t be a problem.
Fertilizer
Rose campion shouldn’t need fertilizer, but if your soil is very thin, adding compost to the planting area may help it to reseed more vigorously.
Types of Rose Campion
There are a number of cultivars available, including a double-flowered version. Some of these may be difficult to find. The gardens at Monticello sell a mix of seeds that contain several cultivars.
‘Abbotsford Rose’: A rose-colored variety popular in England where it was discovered.‘Alba’: This is a white-flowered version that adds a serene coolness to your cottage garden, or is a stellar addition to your moon garden or all-white garden.‘Angel Blush’: This bicolor variety has white flowers with an orchid-pink blush in the center, which varies in size and intensity of color. There are seeds available from several online sellers.‘Astrosanguinea’: Rich magenta flowers and very pale foliage that looks almost white; the “classic” rose campion.‘Dancing Ladies’: These display a mix of white and carmine red, and a darker red eye.‘Flora Plena’: A beautiful double-flowered variety with blooms of deep magenta.‘Oculata’: A white flower with a rose pink or magenta “eye” that may make the flowers look pale pink from a distance.
Pruning
You’ll want to deadhead your rose campion to prevent it from reseeding (unless you want it to), and to remove the dead-looking flowers once the bloom season is done. The leaves provide attractive forms in the winter garden, so you may consider leaving them intact at the end of the season.
Overwintering
Rose campion is known as a short-lived perennial (much like other varieties of dianthus) or a biennial, so it may not return year to year in your garden unless it reseeds. It can reseed easily in the garden under the right conditions, and has the potential to become invasive, popping up unexpectedly. Normally it will reseed in the same general area where it is growing, but if you scatter seed in autumn it may reseed in spring.
Propagating Rose Campion
You can divide rose campion into sections and replant them, but because it is a biennial most people choose to plant from seed for grow more plants in the garden. You can allow them to re-seed naturally, or plant fresh seeds outdoors, in a location of your choosing.
How to Grow Rose Campion from Seed
This is a plant that is seen less often in nurseries than it used to be, but seeds are still widely available. It’s relatively easy to grow from seed although you won’t see blooms until the second year. The seed needs cold stratification to be viable, so planting in fall can yield plants in spring. You can also direct sow in spring after the last frost date. In either case, sow the seeds by pressing lightly into soft damp soil. The seeds are tiny so watering them directly may wash them away; instead try misting them lightly with a sprayer. They need a fair bit of sunlight to germinate in spring, so consider the seasonal placement of the sun in your garden when planting. You can also grow rose campion seeds indoors, just remember to cold stratify before you plant them.
Common Pests and Plant Diseases
Rose campion is very resistant to diseases and pests, making it a carefree addition to your flower bed. If you have problems with deer snacking on your perennial garden, you’ll be pleased to hear that deer don’t enjoy eating rose campion. It’s also not tempting to mice, moles, squirrels, rabbits or other rodents.
