Add it to your home screen and it opens full screen: no browser bars, one tap away, and everything stays signed in. Free, nothing to download from an app store.
- Tap the Share button in your browser
- Scroll down and choose “Add to Home Screen”
- Open GrowSomeFood from your home screen
- Open your browser’s menu
- Choose “Add to Home screen” or “Install app”
- Open GrowSomeFood from your home screen
Periwinkle
The evergreen groundcover sold as creeping myrtle, and one of the most stubborn things in an American woodland. Its mats stop the spring wildflower layer cold. The useful news: it barely sets seed here, so it advances in a slow visible front you can actually beat.
Periwinkle is not food. All parts carry vinca alkaloids: a mouthful of leaves causes vomiting and cramps, and large amounts can drop blood pressure. It is listed as toxic to dogs, cats and horses, and the milky sap irritates some skin, so wear gloves when clearing it. Do not confuse it with Madagascar periwinkle (Catharanthus roseus), the annual bedding plant, which is far more toxic. The main hazard is ecological: dense mats smother the native ground flora.
Overview
Periwinkle (Vinca minor) is the glossy evergreen groundcover sold in every garden center as creeping myrtle - low, tidy, shade-tolerant, deer-proof and almost impossible to kill. Those last two qualities are the problem. Once a planting establishes it creeps outward from rooting stem nodes into a continuous evergreen mat three to six inches deep, and effectively nothing germinates through it. Where it reaches a woodland it erases the spring layer: trillium, bloodroot, trout lily, spring beauty, mayapple and violets simply stop coming back, and with them go the early-season insects and the tree seedlings that would have replaced the canopy.
You have most likely arrived here because you inherited a patch, or because one has crossed a line into your woods. The genuinely useful news is that periwinkle in North America barely sets viable seed. It spreads by creeping, by rooting where it touches down, and by gardeners moving it. That means it advances slowly, in a visible front you can measure and flag, and that almost every wild infestation began either as a deliberate planting or as a dumped load of yard waste. It also means that a cleared patch does not rain back in from the sky the way a bird-spread invasive does. Periwinkle is slow, physical, winnable work - which is more than can be said for most of the plants in this part of the catalog.
Quick facts
For identification. Not a growing guide.
- Life cycle
- Perennial, lives about 30 years
- Where it grows
- Part sun · Part shade · Shade, well-drained soil
- Height
- 6 in3 to 12
- Spread
- 240 in24 to 1200
- Cold
- Takes hard frostdamaged below -30°F
- Heat
- Struggles above 95°F
Through the year
How to recognize it in each season.
Evergreen creeping mat (identify & control)
year-round, every year- Recognize it: glossy paired leaves on trailing stems that root as they goPeriwinkle is a low evergreen trailer, 3-6 inches deep, with small glossy dark-green leaves in opposite PAIRS on wiry, arching stems. The stems run along the ground and root wherever a node touches soil, so the patch advances as a solid mat with a visible outer edge. Broken stems bleed a little milky sap. Bigleaf periwinkle (Vinca major) is the same plant scaled up: leaves 2-3 inches long with hairy margins, stems arching a foot or more.
- Work the edge first, not the middleThe mat expands from its perimeter, so the highest-value work is clearing a clean band around the outside and holding that line each year. Cut, rake and lift the mat like carpet when soil is moist, pulling the rooted nodes rather than snapping the stems. Bag everything - do not compost it and never tip it over a bank or into the woods, which is how most wild infestations started.
Key signs- A solid evergreen mat with a creeping outer front advancing into beds or woods
- Stems rooting at every node where they touch soil
- Bare ground under the mat with no seedlings of anything else coming through
Spring flowers (Mar-May)
Mar to May, every year- Blue-violet pinwheel flowers confirm itIn spring the mat throws single flowers on short upright shoots: five blunt petals set at a slight twist, like a pinwheel, about an inch across, in a soft blue-violet (white and deep purple forms are sold too). They rarely set viable seed in North America. If you are trying to tell periwinkle from a native groundcover, the pinwheel flower over opposite glossy leaves is decisive.
- Spring is when the harm is visibleThis is the month to see what the mat costs you. Compare the ground inside the periwinkle with clean woodland soil a few yards away: the spring ephemerals - trillium, bloodroot, trout lily, spring beauty, mayapple, violets - are absent inside it and present outside. Photograph the edge now; it is the clearest evidence for how far the front has moved by next spring.
Key signs- Blue-violet pinwheel flowers over the mat
- No spring ephemerals emerging inside the mat
- The front line advancing a foot or two per year into new ground
Winter: still green, still spreading
Nov to Feb, every year- Winter is when you can see the whole infestationPeriwinkle never goes dormant. Once the natives have died back and the leaves are off the trees, the mat is the only green thing on the forest floor, and you can map its true extent, its outlying satellites and the paths it is following. Mark the edges with flags now; you will not see them this clearly again until next winter.
- The cold-season treatment windowBecause it stays green and active while natives are dormant, late fall through mild winter spells is the safest time to treat a patch: desirable plants around it are asleep and cannot be harmed by overspray or drift. Work only when the plants are actively growing above roughly 50F, and use a product whose label lists your site - read and follow the label.
Key signs- An evergreen carpet standing out on a bare winter forest floor
- Outlying patches you never noticed in summer
- Stems creeping under fences and across property lines
Watch out for
4 to know. 2 are high-risk: Evergreen Mat Smothering (ecological harm), Regrowth from Rooted Nodes & Fragments. 4 are active in September.
Evergreen Mat Smothering (ecological harm)Severity High DisordernowA continuous evergreen carpet with bare soil beneath it and no seedlings of anything else; spring ephemerals present outside the mat and absent inside it; an advancing front creeping a foot or two per year into beds, lawn edges or woods.
A continuous evergreen carpet with bare soil beneath it and no seedlings of anything else; spring ephemerals present outside the mat and absent inside it; an advancing front creeping a foot or two per year into beds, lawn edges or woods.
Cut the mat short, then rake and roll it up like carpet with the rooted nodes attached while soil is moist; smother what cannot be lifted with cardboard and four to six inches of mulch for one to two full growing seasons; follow up on regrowth for two or three years and replant with natives.
Never plant it, in any cultivar; clear and hold a maintained band around any patch you have inherited; replant cleared ground with native shade groundcovers so bare soil is not left open.
The core hazard is ecological. A periwinkle mat is evergreen, three to six inches deep and continuous, so it holds the soil surface year-round and effectively nothing germinates through it. Woodland spring ephemerals - trillium, bloodroot, trout lily, spring beauty, mayapple, violets - disappear inside it, tree and shrub seedlings fail, and with them go the early-season pollinators and the next generation of canopy. Because periwinkle is strongly deer-resistant, heavy deer browsing on everything around it accelerates the takeover.
Regrowth from Rooted Nodes & FragmentsSeverity High DisordernowVigorous regrowth within weeks of cutting; new plants appearing where clippings or soil were tipped; stems running sideways out from under mulch or cardboard.
Vigorous regrowth within weeks of cutting; new plants appearing where clippings or soil were tipped; stems running sideways out from under mulch or cardboard.
Lift rooted nodes rather than cutting stems; re-inspect cleared ground two or three times over the following year and pull what regrows; check and re-mulch the perimeter of any smothered area monthly through the growing season.
Never tip clippings over a bank, into woods or onto a brush pile; bag material for trash or hot municipal composting; clean tools, mower decks and boot treads before moving from an infested area to clean ground; do not give divisions away.
Why cutting fails and why disposal matters. Every stem node that touches soil roots independently, so a mat is hundreds of separately rooted plants rather than one; mowing or cutting removes leaves and nothing else. Any fragment carrying a node will re-root, including pieces spread by a mower deck, a tiller, or a load of moved soil. Almost every wild infestation in North America began as dumped garden waste or a divided clump given away, because the plant rarely sets viable seed here.
Vinca Alkaloids (people, pets and livestock)Severity Medium DisordernowChildren or pets chewing the glossy leaves, particularly in winter when nothing else is green; skin irritation after clearing a patch bare-handed; grazing animals with access to a mat.
Children or pets chewing the glossy leaves, particularly in winter when nothing else is green; skin irritation after clearing a patch bare-handed; grazing animals with access to a mat.
For ingestion by a person or pet, contact poison control or a veterinarian with the plant name to hand. For skin contact, wash the area with soap and water and treat as contact dermatitis.
Wear gloves and long sleeves when clearing it; keep pets and small children away from established mats; fence livestock off any patch; do not attempt home teas or tinctures from the plant.
A direct hazard to people and animals. All parts of the plant contain vinca alkaloids including vincamine. Eating leaves causes vomiting, abdominal cramps and diarrhea, and larger quantities can cause a marked drop in blood pressure. The plant is listed as toxic to dogs, cats and horses, and the milky sap causes contact irritation in some people. Because it is evergreen, it is one of the few green things available to a curious pet or a browsing animal in midwinter.
Vinca Stem Blight (Phomopsis dieback)Severity Medium DiseasenowFor a reader trying to REMOVE periwinkle, this disease is an opportunity rather than a problem.
Dieback circles are the easiest places to break into a mat, and replanting them with natives immediately is far more effective than clearing healthy mat of the same area.
Sudden wilting of individual shoots, dark lesions and blackening at the base of stems, and enlarging dead patches in an established mat during humid weather.
Where periwinkle is being removed anyway, treat blighted patches as a head start: cut and lift the dead area, bag the debris rather than composting it, and replant the gap with a native groundcover before the surrounding periwinkle closes back over it.
Not something to encourage where you want the plant gone - but note that thinning, improved drainage and avoiding overhead watering are what limit it, and that dense unmanaged mats are the most susceptible.
The fungal dieback that makes established periwinkle plantings collapse in patches. Phomopsis and related fungi infect stems at or near the soil line, girdling them; shoots wilt suddenly, turn dark brown or black from the base, and die, leaving expanding bare circles in an otherwise dense mat. It is worst in humid weather, in overwatered or poorly drained ground, and where the mat is dense enough to stay wet. It is one of the few things that reliably damages this plant.
Grower tips
Notes from growers, tagged with the zone they grow in. A person reads every post before it appears.
Nobody has posted about Periwinkle yet.
Free account. Your post shows your grower name and zone, never your email.