how to control mint in garden

How to Control Mint in the Garden

Mint is a well-known and useful herb that makes many dishes taste and smell great. But because it spreads so easily, mint can quickly go from being a lovely garden plant to an invasive weed that takes over your yard. To grow mint successfully, you need to keep its growth under control and keep its aggressive roots and runners from taking over your lawn or garden beds. You can keep your mint under control and avoid a minty garden nightmare with some smart planting and careful upkeep.

Choosing the Right Mint Variety

Picking the right type of mint for your needs is the first thing you need to do to take care of it. Peppermint (Mentha piperita) and spearmint (Mentha spicata) are the most difficult to control because they are so aggressive. Apple mint (Mentha suaveolens), pineapple mint (Mentha suaveolens ‘Variegata’), and orange mint (Mentha citrata) are all more calm plants. Corsican mint, or Mentha requienii, is a low, creeping type that spreads slowly and is easier to keep in check. Also, think about small garden mints like Mint “Mojito” that were bred not to spread invasively and sterile hybrids that don’t make seeds or runners that can grow.

Planting Mint Properly

Even if you choose a mint that isn’t aggressive, it still needs care when you plant it. Mint should never be mixed in with other plants in the garden. It should always have its own space. Planting mints in pots with no bottom that are sunk into the ground is the safest way to do it. This keeps the plant’s roots from spreading out while still letting it grow normally. Put plastic nursery pots and other small containers, like metal buckets, in the ground at least 8 inches deep. For bigger plants, put planks, cinder blocks, or another barrier 10 to 12 inches deep around the edge of the mint bed. Plant mint in a bed in the ground that doesn’t have any physical barriers between it and other plants. Leave at least 2 to 3 feet of space on all sides.

Caring for Container Mints

Growing mint in above-ground pots is ideal for control. Choose containers at least 12 inches wide and deep to accommodate the plant’s vigorous root system. Make sure the pot has drainage holes to prevent soggy soil. Fill the container most of the way with high-quality potting mix, plant the mint, and water well. As the mint becomes established, check the container regularly to see if roots are escaping from the drainage holes. If so, prune them away to keep the plant contained. Repotting annually helps reduce spreading tendencies as well. Divide congested mint clumps in early spring and repot only the most vigorous sections of roots and crown.

Ongoing Maintenance

Even if mint is planted correctly, it still needs careful care to keep its growth in check:

• Inspect weekly and prune anytime mint plants wander beyond their designated space.

• Cut off runners traveling on top of the soil at least 6-12 inches before the end to prevent new rooting.

• Pull up underground runners carefully to get the entire root and stem.

• Mulch around mint beds to mark its territory clearly.

• Set pitcher pumps, oscillating sprinklers or soaker hoses rather than overhead watering to avoid scattering seeds.

• Remove spent blossoms before they set seeds.

• Top dress container plantings yearly with fresh soil or compost, but avoid high-nitrogen fertilizers that fuel excessive growth.

• Divide potted mints every 2-3 years to rejuvenate and contain them.

Eliminating Out of Control Mint

Sometimes mint plants escape their boundaries and get completely out of hand. Eliminating unruly mint entirely usually requires persistence. Digging up the plant helps, but some roots inevitably get left behind and regrow. Smothering with mulch or landscape fabric slows mint down but doesn’t kill it. Repeated mowing and pruning of top growth eventually weakens the plant, but it takes time.

For the quickest control, most gardeners turn to herbicides. Systemic products that kill right down to the roots work best. Glyphosate (Roundup and others) is effective but also harms surrounding plants. Vinegar or clove oil sprays only injure above-ground parts and regrowth quickly appears. With any treatment, repeatedly treat regrowth for best results eliminating invasive mint.

Prevention is Key

While managing unwelcome mint invasions takes effort, preventing mint from spreading out of control in the first place is much easier. Give all mint plants plenty of breathing space, grow in containers above or below ground, and pay close attention to keeping growth contained within its designated area. With smart preventative planting and vigilant care, you can enjoy the wonderful benefits of fragrant, flavorful mint without it taking over your garden.