How to Grow Supermarket Mint Forever in a Glass of Water

Supermarket mint is usually the biggest culprit: aromatic on the first day, then rather miserable by the weekend. A gardener showed me how to reverse that pattern: keep growing the very same stems indefinitely using only a glass of water.

It started on a crowded kitchen worktop at 5 pm, in that late-afternoon light that can make even a chipped mug appear cinematic. A retired landscaper I had met at the market picked up a bunch of mint from its plastic sleeve, cut it with kitchen scissors and placed the stems in a clear tumbler. There was no rooting powder and no compost - only water, plus a shrug that seemed to say, “Watch.” One week later, pale strands burst from the nodes like miniature fireworks. We sampled the leaves, which tasted as fresh as though they had been grown on a hillside. The glass had done all the growing.

Turn a limp bunch into endless supermarket mint

Mint is determined to survive. That is the understated secret of this method: the plant is ready to send out roots from any node exposed to moisture. Put several supermarket sprigs in water and, within days, they begin a new phase - a soft callus appears first, followed by roots and then fresh leaves that look better than those on the bunch you purchased.

I once tracked a batch bought during a late-night supermarket trip. By the fourth day, small buds were visible; by day eight, they had developed into proper roots. After two weeks, the stems were producing new tips, enough to cut for tea without feeling guilty. One £1.50 bunch provided a regular supply for eight weeks, with three glasses in rotation and no soil anywhere in sight.

The explanation is straightforward plant biology. The tiny bumps on a stem - the nodes - contain dormant growing tissue ready to activate. Give them clean water, oxygen and light, and they produce adventitious roots. Leave the glass in bright, indirect light at room temperature, and the plant puts more energy into rooting than wilting. Good hygiene does most of the hard work.

The water-glass method, step by step

Choose the freshest stems in the packet: they should be firm, green and have undamaged leaves. Cut the bottom of every stem at a slight angle just beneath a node, then remove the lower leaves so that none are submerged. Pour 3–4 cm of water into a clear glass and add 5–7 stems, leaving enough room so they are not packed together.

Set the glass near a bright window where it will receive soft light. Replace the water every two or three days - do not leave it to chance - and rinse out the glass whenever it becomes cloudy. Roots should appear within 5–10 days, while tips can be harvested after 10–14 days. Bright, indirect light is preferable to a hot windowsill that scorches the leaves at midday.

Common mistakes include cramming too many stems into one glass, allowing leaves to sit in water, using strongly chlorinated water or placing mint in direct sun, where the tumbler becomes a miniature sauna. We have all experienced water turning swampy, followed by a spiral of guilt. Honestly, though, nobody does this every day. Aim for “often enough” instead: replace the water before the weekend, give the glass a quick rinse midweek, and you are sorted.

“Treat the water like air,” the gardener told me. “Fresh, clear, moving. Do that, and mint behaves like it’s got a second life.”

• Change the water every 2–3 days to maintain oxygen levels and prevent unpleasant smells.
• Trim below a node to keep the cut end clean and ready to form roots.
• Use just 5–7 stems in each glass to avoid overcrowding and slime.
• Turn the glass regularly so every side receives light; mint grows towards the sun.
• Once roots reach 3–5 cm, pot up some stems and begin new cuttings for the next batch.

Endless mint without making it a chore

The real advantage is that one rooted glass becomes a mint-producing machine. Pinch off the tips for harvesting, then use those newly grown tips as the next set of cuttings. When the roots become dense and stringy, divide the batch: plant half in a pot as a backup and leave the rest in the glass to keep the worktop green. This is the little green trick that never gets old. Give a few rooted stems to a neighbour, bring some along on a picnic or put them in a jar on your desk and watch colleagues gather around like bees. The cycle is easy: trim, sip, repeat. Water restarts the process; the plant handles everything else. Then, on an ordinary Tuesday when dinner needs rescuing, two leaves mixed into yoghurt or crushed into peas can transform the dish - with no urgent supermarket trip required.

Key point	Detail	Benefit for the reader
Cut below a node	Make an angled cut; remove lower leaves so that only the stem sits in water	Quicker, cleaner rooting with less rot
Water discipline	Use a clear glass, change the water 2–3 times weekly and provide soft light	Better-tasting leaves and fewer slimy surprises
Root length = go time	When roots are 3–5 cm long, pot up some stems and restart with fresh cuttings	An endless supply without purchasing new bunches

FAQ:

• How long does supermarket mint last in water? With regular water changes, 4–8 weeks is common. You can begin cutting fresh tips after 10–14 days.
• Tap water or filtered water? Either is suitable. If your tap water has a strong chlorine smell, leave it standing for 12 hours before using it, or use filtered water.
• Why are my stems becoming brown and mushy? The leaves were probably underwater, or the glass was too crowded. Cut away the rot, replace the water and ensure that only stems are below the waterline.
• Can I grow mint forever in water? You can keep the cycle going indefinitely by taking fresh cuttings from growing tips. For added vigour, pot a few rooted stems every couple of weeks and take new water cuttings from them.
• Which mint varieties root best? Spearmint and peppermint root reliably. Chocolate mint, apple mint and Moroccan mint also root well - they simply prefer slightly warmer rooms.