The evergreen perennial we will discuss today is the periwinkle or vinca. In addition to its original rose-pink color, periwinkle flower colors range from white, red, purple, apricot and pink to bi-color blooms. They don’t take a freeze well, but as far as summer bloomers that take the summer heat, these should be in your flower bed for 2023!
You can purchase ready-to-go plants or seeds to begin your periwinkle bed. Seeds take six to eight weeks to reach blooming size, so plan ahead. A site in full sun with good drainage is required for periwinkles. They do not like overly wet soil and root rots can develop – sometimes foliar diseases develop as well. Three good months of blooming is a reasonable goal for this plant.
All is not always well in Periwinkle-Ville! As mentioned earlier, although very heat tolerant, periwinkles do not like to be too wet. The arrival of heavy summer rains may promote and trigger a variety of fungal diseases that can take your periwinkles down. Fortunately, if you have had problems with mid-summer periwinkle failures, there is a variety called ‘Cora’ which has bred-in foliage disease resistance. ‘Cora’ periwinkles come in a good number of colors (and larger flowers) to satisfy any taste. Specifically, Cora™ is resistant to the aerial Phytophthora fungus. You may also see Nirvana™ brand periwinkles. These are just the same but are vegetatively produced instead of started from seed. Cora™ is not only disease-resistant, but also more attractive! The leaves and the flowers of this series are larger, and the foliage is glossy and deep green. The colors come in a wide assortment including white, lavender, deep lavender, apricot with a red center, pink, burgundy and violet.
While periwinkles can grow upwards to two to three feet at maturity and get a bit leggy, most will be around fourteen to sixteen inches tall. Each plant develops into a mounding specimen suitable for edging, as groundcover, mass planting, cascading down a wall and even in a hanging basket. Periwinkles flourish in poor soils, so don’t feel the need to add any organic matter which would tend to make the soil retain excess moisture. Also, when planting, plant them high and not deeper as you might some seedlings. Culturally, this will help reduce the chances of root rot issues.
While periwinkles have their challenges, they are fully worthwhile, and gardeners should plant more! For more information on all types of flowers suitable for our area, or to ask a question, you can also call the Master Gardener Volunteer Helpdesk on Mondays, Wednesdays, and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Ralph E. Mitchell is the Director/Horticulture Agent for UF/IFAS Extension – Charlotte County. He can be reached at 941-764-4344 or ralph.mitchell@charlottecountyfl.gov, Connect with us on social media. Like us on Facebook @CharlotteCountyExtension and follow us on Instagram @ifascharco.
Resources:
Gilman, E. F. & Howe, T., Klein, R. W. & Hansen, G. (2023) Catharanthus roseus Periwinkle, Madagascar Periwinkle. The University of Florida Extension Service, IFAS.
Vinca Cora Series (2023) Texas Superstar® program, of Texas AgriLife Research, Texas A&M University.
(2021) UF/IFAS Gardening Solutions. Periwinkles. The University of Florida Extension Service, IFAS.
Caldwell, D. (2008) A Rainey Season Periwinkle? The University of Florida Extension Service, IFAS – Collier County.
3
