Does Vinca Kill Other Plants?

Vinca, commonly known as periwinkle or myrtle, can kill or crowd out other plants under certain conditions, mainly due to its aggressive spreading habit and potential allelopathic effects. The answer depends on the vinca species, your garden setup, and how you manage it. This article explains exactly when vinca becomes a problem and how to control it so your other plants survive and thrive.

What Kind of Vinca Are You Dealing With?

Two main types are sold in gardens: Vinca minor (lesser periwinkle) and Vinca major (greater periwinkle). Both are evergreen ground covers, but their behavior differs.

Vinca minor – Smaller leaves, slower spread, less aggressive. It stays under 6 inches tall and is easier to contain.
Vinca major – Larger leaves, faster growth, can climb and smother. It reaches 12–18 inches and spreads more vigorously.

A third type, annual vinca (Catharanthus roseus), is a different plant altogether. It is not a true vinca, does not spread aggressively, and rarely kills other plants. This article focuses on the perennial Vinca species.

Does Vinca Spread and Smother Other Plants?

Yes, vinca can physically smother neighboring plants. It spreads by stolons – above-ground runners that root at nodes along the stem. Given time, a single vinca plant can form a dense mat that blocks sunlight and air from reaching low-growing plants underneath.

The danger is greatest for small, shallow-rooted plants such as annual flowers, young perennials, and bulbs. Vinca’s mat can be 4–6 inches thick in Vinca major, enough to prevent seeds from germinating and to starve small plants of light.

Does Vinca Release Chemicals That Kill Other Plants?

Vinca is suspected to be allelopathic, meaning it releases natural chemicals into the soil that inhibit the germination or growth of competing plants. While research is not as solid as for plants like black walnut or ragweed, many gardeners report that vinca seems to suppress weeds and nearby ornamentals more than simple shading would explain.

A 2016 study on Vinca major extracts found they reduced seed germination in several test species. This suggests that, even after you remove vinca physically, the soil may still hinder replanting for a few weeks. If you notice that nothing grows well in a spot where vinca previously thrived, allelopathy could be the culprit.

When Is Vinca Most Likely to Kill Other Plants?

Vinca poses the greatest risk to other plants in these conditions:

In small garden beds – Vinca quickly overtakes limited space.
Near slow-growing plants – Shrubs and perennials that grow slowly can be overwhelmed.
In shaded, moist areas – Vinca thrives here, while many other plants already struggle.
When left unchecked for a season or more – A single plant can cover several square feet in one year.
Near seedlings or newly transplanted plants – Vinca’s mat smothers tender growth fast.

How to Prevent Vinca from Killing Other Plants

Prevention is far easier than removal. Use these strategies to keep vinca under control without sacrificing your other plants.

1. Choose Vinca minor over Vinca major

If you must plant vinca, stick with Vinca minor. It spreads about half as fast as Vinca major and is easier to trim. Cultivars like 'Bowles' Common' or 'Illumination' are popular and less aggressive.

2. Install physical barriers

Bury a metal or plastic edging strip 6–8 inches deep around the vinca bed. Vinca roots and stolons rarely penetrate deeper than that. This keeps runners from invading adjacent beds. For extra security, use a garden edging roll that is at least 10 inches tall.

3. Create a border of bare ground or gravel

A 12-inch gap of bare soil or crushed gravel around the vinca patch makes it easy to spot and remove wandering runners before they root.

4. Prune back stolons monthly

During the growing season, walk the border and snip off any runners that cross the barrier. Use a pair of pruning shears to cut them cleanly. This takes 5 minutes per month and prevents spreading.

5. Mulch heavily around other plants

A 3-inch layer of organic mulch (wood chips or bark) around your valued plants creates a tough barrier that makes it harder for vinca stolons to root nearby.

Can Vinca and Other Plants Coexist Peacefully?

Yes, but with careful planning. Vinca works well as a ground cover under large trees and shrubs where little else grows. It pairs with:

Large shade trees – Vinca fills empty space without harming tree roots.
Tall shrubs – Shrubs like rhododendrons or hydrangeas grow above vinca and are not smothered.
Bulbs – Spring bulbs (daffodils, snowdrops) emerge before vinca leafs out fully and can coexist.

Avoid planting vinca near:

Low-growing perennials (creeping phlox, thyme, sedum)
Annual flower beds
Vegetable gardens
Rock gardens or alpine plants
Small native wildflowers

How to Remove Vinca If It Has Already Killed Other Plants

Removing established vinca requires persistence. Follow this step-by-step plan:

Cut or mow the vinca as low as possible in early spring. Dispose of the cuttings in the trash – do not compost them.
Dig out the roots and stolons with a garden fork or shovel. Try to remove all white, fleshy roots. This is labor-intensive but most effective.
Cover the area with cardboard or black plastic for at least one full growing season. This blocks light and starves any remaining roots.
Monitor for regrowth – pull any new shoots immediately.
Solarize the soil in hot summer: wet the area, cover with clear plastic, and leave it for 4–6 weeks. This kills vinca and reduces allelopathic residues.

If digging is not practical, spot-treat with a glyphosate-based herbicide on the cut stolons. Be careful – glyphosate kills any plant it touches. For a non-chemical alternative, use a garden weeder tool to pry out roots without bending.

Should You Plant Vinca at All?

Given its potential to become invasive and kill other plants, many gardeners choose alternatives. Consider these non-invasive ground covers that perform a similar role:

Plant	Spread rate	Light	Notes
Ajuga	Medium	Partial to full shade	Colorful foliage, bees love flowers
Pachysandra	Slow to medium	Full shade	Evergreen, non-invasive
Hosta	Clump-forming	Shade	Larger leaves, easy to divide
Lamium	Medium	Partial shade	Variegated leaves, pollinator-friendly
Wild ginger	Slow	Deep shade	Native in many regions, low growing

If you still want vinca, use it only in contained areas where you can monitor it. Never plant it near natural areas or woodlands – it escapes easily and displaces native plants.

Common Mistakes That Lead to Vinca Problems

Many gardeners accidentally create vinca invasions. Avoid these errors:

Planting vinca directly into flower beds – always use a border or container.
Assuming vinca stays where you put it – it does not. Expect it to spread.
Mulching over vinca runners – mulch does not stop them; it hides them until they root.
Waiting too long to prune – one missed month can allow a runner to set roots 3 feet away.
Composting vinca clippings – stolons can root in compost and survive.

Signs That Vinca Is Harming Your Garden

Watch for these indicators that your vinca is killing nearby plants:

Yellowing or stunted leaves on neighboring plants.
Bare patches where nothing grows under or near the vinca.
Thinning of lawn or ground cover adjacent to a vinca patch.
Small plants that simply vanish after a season.
Soil that feels dry and compacted under the vinca mat.

Does Vinca Kill Trees?

No, vinca does not kill established trees. It can climb the trunk a bit, but it rarely harms the tree. In fact, vinca is often planted under trees precisely because it coexists fine with large roots. However, young trees with thin bark may be smothered if vinca wraps around the trunk. Keep vinca at least 12 inches away from the base of young trees.

Final Thoughts on Vinca’s Impact on Other Plants

Vinca can absolutely kill other plants – not through intentional aggression, but because it is a tenacious, fast-spreading ground cover that outcompetes slower neighbors for light, water, and soil resources. Whether it becomes a problem depends on the species you plant, where you plant it, and how much you prune. With proper edging, monthly maintenance, and careful site selection, you can enjoy vinca’s glossy evergreen leaves and blue flowers without sacrificing the rest of your garden. If you want zero risk of killing neighbor plants, choose a slower, clumping ground cover instead.