Ornamental · Apocynaceae
Common Periwinkle
Vinca minor
A tough evergreen groundcover that carpets dry shade in blue, just keep its runners in check.
Partial shade
Every 7–14 days
USDA 4–9
3–6 in · 8–15 cm
Overview
Common periwinkle is the low, trailing evergreen that turns bare ground under trees into a sheet of glossy green and spring blue. It belongs to the dogbane family and grows as a hardy perennial, holding its leaves through winter and spreading by stems that root as they run. Few plants ask so little and cover so much.
Gardeners reach for it where almost nothing else will grow. It takes dry shade, poor soil, and slopes that erode, and once it is established it shrugs off drought. The flat mats also smother weeds, which is half the reason it has been a groundcover staple for so long.
That same vigor is the catch. Periwinkle escapes gardens easily and invades woodlands, crowding out native wildflowers and tree seedlings, so it is best kept inside a defined bed and well away from natural areas. Every part of the plant is also toxic, which is worth knowing before you plant it where pets or children roam.
Care
The short version: part to full shade, average well-drained soil, and a deep drink only during dry spells, with a shearing each spring to keep it tidy and contained.
Light
Periwinkle does best in part to full shade, which is why it shines under trees where grass gives up. It will take full sun in cooler regions, but in hot summers strong sun scorches the leaves unless the soil stays moist.
Water
Keep the soil moist but well drained while plants settle in, watering every 7 to 14 days during dry spells and a bit more often in full sun. Once established it handles drought well. Water at the base rather than overhead, since wet foliage invites fungal disease.
Soil
Average, well-drained soil suits it fine, and it tolerates clay, loam, sand, and dry rocky ground alike. It grows best in moist, humusy soil with a pH from 6.0 to 7.5, comfortably on the neutral side.
Temperature
This is a cold-hardy groundcover, taking temperatures from about -29°F to 95°F (-34°C to 35°C). It holds its evergreen leaves through hard winters and only struggles where summer heat meets dry, sunny ground.
Humidity
Ordinary outdoor humidity is all it asks, so there is no number to hit. Airflow matters more than moisture in the air, because crowded, damp plantings are where stem canker and leaf spot take hold.
Feeding
Periwinkle rarely needs feeding and gets by on poor soil without complaint. If growth looks weak, a light spring application of balanced all-purpose fertilizer is plenty.
Pruning
Shear or mow established plantings in early spring to freshen the growth and rein in the spread. The same pass clears out any winter-damaged or diseased foliage before new leaves push.
Repotting
Grown in the ground it never needs repotting, and even in a container it rarely does. Watch for roots circling the pot, slowing growth, or poking from the drainage holes as the signs it is rootbound and ready for more room.
Size & spacing
Each plant stays low at 3 to 6 inches (8 to 15 cm) tall but spreads 6 to 18 inches (15 to 46 cm) wide and keeps going. Set plants on that spacing and they knit into a solid mat within a season or two.
When to plant
Periwinkle is hardy from zones 4 through 9 and goes in the ground in spring or early fall, while the soil is cool and moist enough for the roots to take hold. It blooms from spring into early summer, roughly May to June, then throws out scattered flowers through the warmer months.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or early fall
- Harvest: Spring into early summer (May to June), with sporadic rebloom through summer and fall
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Most periwinkle trouble comes down to one of two extremes: too much vigor or too much wet. Read the early signs below and you can rein in a runaway patch or head off disease before it spreads. Match what you see, then act while it still helps.
Stems that root as they run and swallow the bed
This is invasive spread, the same trait that makes periwinkle such a tough groundcover. Trailing stems root wherever they touch soil, so a tidy patch creeps into lawns, beds, and nearby woods and smothers everything in its path. Dig and pull the escaping runners, edge the bed with a barrier, and bin every rooted fragment rather than composting it, because one missed scrap starts the whole thing over.
Fix:
- Pull, dig, or cut back escaping stems and remove rooted fragments
- Mow or shear to contain edges and install an edging barrier
- Dispose of clippings and pulled plants in the trash, not in yard waste or woods, to prevent spread
- Repeat removal over several seasons since regrowth is common
Brown dying patches with sunken cankers near the soil
This is fungal stem canker and dieback, the most common disease of periwinkle, and it takes hold where plantings sit crowded, wet, and poorly drained. Watch for sunken wound-like lesions on the stems near the ground and brown circular spots on the leaves within a fading patch. Thin out the affected growth to open up airflow, water at the base instead of over the top, and rake away the infected debris so spores have nowhere to overwinter.
Fix:
- Thin and remove affected stems and leaves to improve air circulation
- Avoid overhead irrigation and water at the base
- Rake out and discard infected debris
- Reduce overcrowding when replanting
Leaves scorching and yellowing in hot, dry sun
This is heat and drought stress, and it shows up only on plants baking in full sun with no moisture to draw on while shaded, well-watered patches stay green. Water deeply through dry spells and lay down mulch to hold what moisture there is. Where summers run hot, give periwinkle the part to full shade it actually prefers.
Fix:
- Water deeply during dry periods
- Mulch to conserve soil moisture
- Site in partial to full shade where summers are hot
Toxicity
Treat periwinkle as a toxic plant from top to bottom. Every part holds vinca alkaloids, the same family of compounds used in chemotherapy drugs, and chewing or swallowing it causes drooling, vomiting, and diarrhea, with low blood pressure, tremors, and even seizures after a large dose. Keep the plant and its trimmings away from cats, dogs, horses, livestock, birds, and children, and call your vet or poison control if any is eaten.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Moderate
A nibble of leaves or stems brings on drooling, vomiting, and diarrhea. Eat much, and the alkaloids can drop blood pressure, set off tremors, and in quantity bring seizures.
Dogs Moderate
Chewing the foliage tends to cause drooling, vomiting, and diarrhea fairly quickly. A large mouthful is the real worry, since it can lower blood pressure and trigger tremors or even seizures.
Horses Moderate
Grazing on periwinkle upsets the gut with drooling, vomiting, and diarrhea, and a horse's size is no protection. Bigger doses bring low blood pressure, tremors, and seizures.
Rabbits Toxic
The same vinca alkaloids make every part of the plant unsafe to feed. Expect drooling and a badly upset stomach, with tremors and collapse if a rabbit eats much, so keep it well out of reach.
Livestock Toxic
Cattle, goats, and sheep all react to the alkaloids in the leaves and stems with drooling, vomiting, and diarrhea. Heavier grazing can bring on falling blood pressure, tremors, and seizures.
Birds Toxic
No part of periwinkle is safe for birds to peck or eat. Even small amounts can cause drooling and stomach upset, and more can lead to tremors and seizures.
People Caution
Nothing on this plant is meant to be eaten, so treat it as a hazard for curious children. Swallowing leaves or stems can cause drooling, vomiting, and diarrhea, and a large amount may drop blood pressure or bring tremors.
Keep plants and trimmings away from pets and children; wash hands after handling and dispose of clippings where animals cannot reach them.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Periwinkle comes in more than the plain blue most people picture, from white and burgundy flowers to gold-splashed leaves. These are the selections worth knowing by name.
Bowles (Bowles' Variety / 'La Grave')
A vigorous selection carrying larger, deep lilac-blue flowers, and it ranks among the most popular periwinkle cultivars you can buy.
'Atropurpurea' (sold as 'Burgundy')
This one trades the usual blue for deep reddish-purple to burgundy flowers.
'Alba'
A white-flowered form of common periwinkle for gardeners who want the same trailing habit without the blue.
'Illumination'
Grown mostly for its bright gold-and-green variegated leaves, set off by blue flowers.
'Jekyll's White'
A compact, white-flowered selection that stays neater than the spreading types.
Vinca major (Bigleaf/Greater Periwinkle)
A larger, more aggressive relative that mounds up to about 2 feet with bigger 1 to 2 inch blue flowers, and it turns even more invasive in mild climates.
Vinca major 'Variegata'
A variegated bigleaf periwinkle edged in creamy white, often used to spill over containers and hanging baskets.
How to propagate
Periwinkle practically multiplies itself, and you can speed it along by cuttings, division, or simple layering of the stems it already roots on its own.
Stem cuttingsEasy
Late spring to summer · A few weeks to root; full groundcover in 1-2 seasons
Take tip cuttings from non-flowering stems in late spring or summer and they root with little fuss. Give them a few weeks to take hold, and they fill in to a complete groundcover within one to two seasons.
DivisionEasy
Throughout the growing season · Establishes quickly; complete cover in 1-2 years
Lift a rooted clump or a rooted trailing stem any time through the growing season and replant it where you want more. It settles in fast and knits into full cover within a year or two.
LayeringEasy
Growing season · Roots where stems touch soil within weeks
Periwinkle layers itself without your help during the growing season. Wherever a trailing stem rests on moist soil it strikes roots at the node within weeks, and you can sever and move the new plant once it has taken.
Myths
Trailing groundcover periwinkle is the same plant as the annual bedding vinca.
They share the name vinca but they are not the same plant. The trailing evergreen perennial groundcover is Vinca minor, while the upright annual sold for flowerbeds is Madagascar periwinkle, Catharanthus roseus, once called Vinca rosea. Both sit in the dogbane family and both are toxic, but the annual carries even stronger vinca alkaloids such as vincristine and vinblastine.