How to Get Rid of Mint in the Garden

Mint is a versatile herb, but if left unchecked, it can quickly overrun your garden. Many Kiwis find themselves wondering how to get rid of mint in garden beds without harming nearby plants. With the right strategies, you can reclaim your garden space while keeping other greenery safe.

Discussion Points:

Why mint spreads so aggressively
The risks of letting mint grow unchecked
Manual and natural removal methods
Safe containment strategies to prevent regrowth
Common mistakes to avoid
When to call in professional help

Why Mint Becomes a Problem

Mint might look harmless at first, but beneath the surface it’s a completely different story. Mint spreads through underground rhizomes—horizontal stems that travel just below the soil surface. These rhizomes can extend well beyond where you originally planted the herb, producing new shoots wherever they settle.

Over time, these shoots form dense mats of roots that smother the soil, making it difficult for other plants to grow. What starts as a small patch of mint can quickly creep into borders, vegetable patches, and even lawns, leaving little room for anything else.

Because rhizomes are tough and flexible, they often weave through root systems of neighbouring plants. This makes it hard to remove mint completely without disturbing the rest of your garden. Left unchecked, mint doesn’t just coexist—it dominates, and that’s when it disrupts your garden’s natural balance.

Risks of Uncontrolled Mint Growth

Crowding out other plants: Mint has an aggressive growth habit, competing fiercely for soil nutrients, water, and sunlight. Tender vegetables and flowers often lose out.
Invasive root systems: The underground rhizomes travel far beyond the original planting spot, sometimes popping up metres away.
Difficult eradication: Even the tiniest piece of rhizome left in the soil can regenerate into a new plant. This means one half-hearted removal attempt won’t work.

While mint adds amazing flavour to teas, desserts, and cocktails, in the garden it’s more like a weed if not controlled. It’s best to contain it from the start or act quickly before it spreads.

Manual and Natural Removal Methods

1. Uprooting by Hand

Digging up mint is the most direct method, but it requires patience.

Use a garden fork or spade to carefully loosen the soil. Avoid pulling mint stems by hand, as they’ll snap easily and leave roots behind.
Remove as much of the rhizome system as possible, following roots laterally through the soil.
Expect to repeat this process several times, as missed fragments can sprout again.

Tip: It’s easiest to do this after rain or watering, when the soil is moist and roots come up more cleanly.

2. Smothering the Roots

If digging isn’t practical, smothering works well in larger infested areas.

Lay down several layers of cardboard or newspaper, or use black plastic sheeting to block sunlight.
Weigh the covering down with soil, mulch, or stones.
Leave it in place for several weeks to months, checking occasionally for any mint shoots trying to break through.

This method deprives mint of light and oxygen, weakening the rhizomes until they can no longer regenerate. Once removed, you can replant the area with less aggressive species.

3. Frequent Cutting

Mint relies heavily on its leaves for energy through photosynthesis. By cutting stems down repeatedly, you deprive the plant of energy, gradually starving it.

Use sharp shears to cut plants back to ground level.
Collect and dispose of the clippings rather than composting them—some pieces may still root if conditions are right.
Combine cutting with root removal for the most effective results.

This method works best when you’re trying to gradually weaken mint over a growing season.

Safe Containment Strategies

If you enjoy the fresh taste of mint in teas, desserts, or cooking, you don’t have to banish it from your garden completely. The key is containment. Here are several safe and effective ways to grow mint without letting it take over:

1. Plant in Pots or Containers

One of the easiest methods is to grow mint in a pot.

Choose a deep container (at least 30–40 cm) to give the roots room but prevent them from spreading outward.
You can sink the pot into your garden bed so the top rim sits just above soil level. This keeps the mint accessible while blocking rhizomes from escaping underground.
For extra security, line the pot with mesh or landscape fabric before filling it with soil.

2. Raised Garden Beds

Growing mint in a raised bed keeps it separate from the rest of your plants.

Dedicate one raised bed to herbs like mint, lemon balm, and oregano that share similar spreading tendencies.
Make sure the raised bed has a solid base or weed matting underneath to stop roots from tunnelling into the soil below.
Position the bed in a sunny corner where mint can thrive without competing with vegetables or flowers.

3. Root Barriers

If you prefer mint directly in the ground, root barriers can help.

Use physical barriers such as heavy-duty plastic edging, metal sheets, or even old buckets with the bottoms removed.
Bury the barrier at least 30–40 cm deep, as rhizomes can travel surprisingly far below the soil surface.
Allow the barrier to extend several centimetres above the ground to prevent roots from creeping over the top.

4. Regular Maintenance

Even with containment, mint requires ongoing monitoring. Check the edges of pots, beds, or barriers every few weeks for escaping shoots and cut them back promptly. A little routine attention will keep mint manageable while still providing you with plenty of fresh sprigs.

By using these containment strategies, you can enjoy mint’s benefits in the kitchen and garden without worrying about it invading every corner of your property.

Common Mistakes to Avoid

When dealing with mint, it’s easy to make mistakes that end up worsening the problem. Here are the pitfalls to steer clear of:

Using harsh chemicals – Herbicides might seem like a quick fix, but they often harm neighbouring plants, contaminate soil, and disrupt the microbial balance. Mint is so resilient that chemical sprays rarely eliminate it completely.
Pulling only the stems – Tugging mint stems by hand may remove the top growth but leaves rhizomes intact. Those underground runners will quickly send up new shoots, undoing your hard work.
Planting mint directly in open beds – Planting mint in unrestricted garden beds is almost guaranteed to lead to spread. Unless you want mint everywhere, always contain it from the start.
Composting mint roots – Even after pulling, small root fragments may survive composting and re-establish themselves when used later in the garden. It’s safer to dry or dispose of pulled roots.

By avoiding these mistakes, you’ll save yourself time, effort, and the frustration of repeated regrowth.

When to Call for Help

Jim's NZ team

Persistent mint infestations can be overwhelming, especially when roots spread deep into vegetable patches or lawns. If DIY methods aren’t working, professional garden maintenance can help restore order. The team at Jim’s Mowing NZ has experience managing invasive plants while protecting the rest of your garden.

Conclusion

If you’re asking yourself, “how to get rid of mint in garden without killing other plants,” the solution lies in careful root removal, containment, and persistence. By managing mint properly, you’ll protect your garden’s health. For expert gardening services across New Zealand, call Jim’s Mowing NZ at 0800 454 654.