Ornamental · Apocynaceae
Common Periwinkle
Vinca minor
An evergreen carpet of glossy green leaves and blue spring flowers riding low, rooting stems.
Partial shade
Every 7–14 days
USDA 4–9
3–6 in · 8–15 cm
Overview
Common periwinkle lies flat and low to the ground, a mat of small, glossy green leaves that stay on the plant all winter. Slender, trailing stems run outward and press against the soil, striking roots at the points where they touch. In spring the green fills with blue flowers, the color that gives the plant its name.
The leaves hold a hard, polished shine that catches light even in the dry shade where the plant grows thickest. Stem after stem overlaps into a dense, even layer only a few inches deep, so the surface reads as one continuous sheet of green rather than separate plants. Where the soil is poor or a slope falls away, that low green skin still knits together and holds.
For all the softness of the color, the plant is a spreader. The same rooting stems that build the mat keep pushing past its edge and into woodlands, laying green over the ground where native wildflowers and tree seedlings would rise. Every part of it, leaf and stem alike, holds toxic alkaloids, so the tidy green surface is best kept where curious mouths cannot reach.
Care
The short version: part to full shade over average well-drained soil, a deep soak only in dry spells, and a spring shearing keep the low green mat dense and in bounds.
Light
Periwinkle keeps its deepest, glossiest green in part to full shade, where its leaves lie thickest under trees. Full sun works in cooler regions, but under hot summer sun the leaves scorch and brown unless the soil beneath them stays moist.
Water
Keep the soil moist but well drained while the roots take, watering every 7 to 14 days in dry spells and more often where the sun is full. Once established, the plant holds its green through drought. Send the water to the base and off the leaves, since a wet leaf surface is where fungal disease begins.
Soil
Average, well-drained soil carries it, and the roots take equally to clay, loam, sand, and dry rocky ground. The leaves grow fullest and greenest in moist, humusy soil at a pH of 6.0 to 7.5, close to neutral.
Temperature
The evergreen leaves hold their color through a punishing range, from -29°F to 95°F (-34°C to 35°C). They stay green and firm through hard winters, softening only where summer heat lands on dry, sunny ground.
Humidity
Plain outdoor air is enough, so there is no reading to chase. Air moving over the leaves matters more than moisture within it, because still, damp, crowded growth is where stem canker and leaf spot mark the green.
Feeding
The plant colors up well on poor ground and seldom needs feeding. When the green looks thin and pale, a light spring feeding of balanced all-purpose fertilizer fills it back in.
Pruning
Cut the established mat back with a shear or mow in early spring, and fresh green pushes up in its place. The same pass strips out the leaves left brown or diseased by winter before new growth covers them.
Repotting
Set in the ground the plant never needs repotting, and potted it rarely does. Roots circling the pot, growth slowing, and roots pushing from the drainage holes are the visible signs it has grown rootbound and needs more room.
Size & spacing
Each plant sits low, just 3 to 6 inches (8 to 15 cm) of leaf above the soil, while its stems reach out 6 to 18 inches (15 to 46 cm) and keep going. Set at that spacing, the overlapping stems close into one unbroken green surface within a season or two.
When to plant
Hardy through zones 4 through 9, periwinkle goes into cool, moist ground in spring or early fall. The blue flowers open from spring into early summer, around May to June, dotting the green surface, then reappear here and there 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 trouble shows plainly on the plant itself: a mat pushing past its edge, or brown, failing patches where the green should be solid. The signs below tell a spreading problem from a diseased one at a glance. Look closely, then act on what the leaves and stems are showing.
Stems creeping out and rooting into a solid green mat
This is invasive spread, the same reach that fills the bed with unbroken green. Each trailing stem lays flat and roots where it meets the soil, so the green edge keeps sliding into lawns, beds, and nearby woods and covers whatever was there. Dig and pull the runners at the margin, sink an edging barrier at the line, and drop every rooted piece in the trash rather than the compost, since one rooted node grows the whole green sheet again.
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, sunken patches where the green mat dies out
This is fungal stem canker and dieback, the most common blight on periwinkle, and it eats into growth left crowded, wet, and slow to drain. The tell is a sunken, wound-like scar low on the stems and brown circular spots freckling the leaves inside a browning patch. Thin the growth to move air across the stems, water at the base to keep the leaves dry, and rake the browned debris away so nothing carries the spores over winter.
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 browning and yellowing under hot, dry sun
This is heat and drought stress, and it burns only the leaves in full sun with no moisture below them, while shaded, watered growth stays firm and green. Water deeply through the dry stretch and spread mulch to hold the dampness in the soil. Where summers turn hot, the part to full shade periwinkle prefers keeps the leaves from scorching in the first place.
Fix:
- Water deeply during dry periods
- Mulch to conserve soil moisture
- Site in partial to full shade where summers are hot
Toxicity
Behind the plain green surface, periwinkle is toxic in every part. Leaf and stem alike hold vinca alkaloids, the same class of compounds used in chemotherapy drugs, and chewing or swallowing them brings drooling, vomiting, and diarrhea, with low blood pressure, tremors, and even seizures after a large amount. Keep the plant and its cut stems 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 single bite of the glossy leaves or stems starts drooling, vomiting, and diarrhea. More than that lets the alkaloids drop blood pressure, bring on tremors, and in quantity trigger seizures, so keep the plant out of reach.
Dogs Moderate
Teeth crushing the foliage release enough alkaloid to bring drooling, vomiting, and diarrhea quickly. A large mouthful is the real danger, since it can lower blood pressure and set off tremors or seizures.
Horses Moderate
A mouthful of periwinkle turns the gut over with drooling, vomiting, and diarrhea, and the animal's bulk is no shield. Larger amounts drag blood pressure down and bring tremors and seizures.
Rabbits Toxic
The alkaloids run through every part of the plant, so none of it is safe for a rabbit to strip and chew. Drooling and a badly turned stomach follow, with tremors and collapse if much goes down.
Livestock Toxic
Cattle, goats, and sheep that tear at the leaves and stems take in the alkaloids and show drooling, vomiting, and diarrhea. Heavier grazing pulls blood pressure down and brings tremors and seizures.
Birds Toxic
Not a leaf or stem of periwinkle is safe for a bird to peck. Even a small amount starts drooling and a churning stomach, and more brings tremors and seizures.
People Caution
Nothing on the plant is food, which makes the glossy leaves a lure to watch around children. Swallowed leaves or stems bring drooling, vomiting, and diarrhea, and a large amount can drop blood pressure or set off 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
Past the familiar blue, periwinkle shifts in flower color and leaf pattern, from burgundy and white blooms to leaves streaked with gold. These are the forms worth telling apart by sight.
Bowles (Bowles' Variety / 'La Grave')
A vigorous form set with larger flowers in a deep lilac-blue, and one of the most widely grown periwinkle cultivars.
'Atropurpurea' (sold as 'Burgundy')
Its flowers deepen from blue to a rich reddish-purple, close to burgundy.
'Alba'
The same low trailing green, but its flowers open pure white instead of blue.
'Illumination'
Its leaves are marked bright gold and green, with blue flowers set against the variegation.
'Jekyll's White'
A compact, white-flowered form that holds a tighter, neater shape than the spreading types.
Vinca major (Bigleaf/Greater Periwinkle)
A bigger, coarser relative that mounds to about 2 feet, its blue flowers widening to 1 to 2 inches, and it spreads even harder in mild climates.
Vinca major 'Variegata'
A bigleaf periwinkle whose leaves are rimmed in creamy white, its trailing stems often left to spill from containers and hanging baskets.
How to propagate
The plant roots so readily along its own stems that making more of it is largely a matter of following what the stems already do, by cuttings, division, or layering.
Stem cuttingsEasy
Late spring to summer · A few weeks to root; full groundcover in 1-2 seasons
Cut the growing tips from non-flowering stems in late spring or summer and they root readily. Roots form in a few weeks, and the cuttings knit into a full green cover within one to two seasons.
DivisionEasy
Throughout the growing season · Establishes quickly; complete cover in 1-2 years
Lift a rooted clump or a single rooted stem at any point in the growing season and set it down where more green is wanted. It takes hold fast and closes into full cover within a year or two.
LayeringEasy
Growing season · Roots where stems touch soil within weeks
Left alone through the growing season, periwinkle layers itself: any stem lying on moist soil sinks roots at the node within weeks. Once those roots hold, the new plant can be cut free and moved.
Myths
Trailing groundcover periwinkle is the same plant as the annual bedding vinca.
The name is shared, but the two plants look and grow nothing alike. The low, trailing evergreen groundcover is Vinca minor, while the upright annual sold for flowerbeds is Madagascar periwinkle, Catharanthus roseus, once called Vinca rosea. Both belong to the dogbane family and both are toxic, though the annual carries even stronger vinca alkaloids such as vincristine and vinblastine.