mint leaves

How to Grow Mint

Mint is an easy to grow, low-maintenance perennial herb. It is a great culinary herb used for tea and other drinks, sauces, salads and deserts. It is also one of the best herbs for attracting beneficial insects to your garden. Mint is best grown in pots as it tends to spread very easily!                                  

If you know someone with Mint in their garden, we’re sure they’d be happy to share a root cutting with you! Otherwise you can follow the sowing advice below. There are many different mint varieties available, such as Ginger, Strawberry and Chocolate mint to buy or sow!

Sowing 

To harvest the same year, ideally start sowing late winter to early spring. Having said that, it is possible to sow all year around in your Harvst S-Series Mini Greenhouse. Fill a pot or tray with peat-free seed compost, water it and then thinly sow the seeds on top. The seeds are tiny so try your best at spacing them out and thin later if necessary.  Cover the seeds lightly with compost or vermiculite, and water again carefully. Putting a plastic dome or cling film on top can help germination, but make sure it has air holes for ventilation. Keep the soil evenly moist until the seeds germinate. If they dry out, it’s likely they won’t germinate at all. Having said that, be careful not to overwater!

Mint will ideally need 15-20°C to germinate well and should appear within 7- 14 days. Once the seedlings appear, remove the plastic and place in a bright location to grow on.

Plant care 

There’s no need to thin the seedlings out unless the pot is very crowded. When they are about 5cm high, transplant into 15-20cm pots using peat-free multi-purpose compost. Grow them on in cooler conditions.  

You can keep the pot in your Mini Greenhouse or put it outside in early summer after the last frost. To acclimatise the plants to outdoor conditions, lift them outside in a sheltered, lightly shaded spot during the day, and put them back in at night. Gradually increase the time outside. Do this for about two weeks before leaving them out all the time.

Try to keep the pots well watered. If possible, water in the morning so that the leaves can dry up during the day to avoid fungal disease. 

Mints are perennial plants that die back in winter and regrow in spring, so don’t throw them away when they look dead in the winter! Pot grown mint will need dividing every couple of years. Simply lift and divide the crowded plant and repot into individual pots.

Harvesting 

Like most herbs, Mint is best used fresh so harvest as required – preferably in the morning. You can start harvesting as soon as leaves appear in spring and continue through to the first frosts. For the best flavour, keep cutting mint to stimulate new leaf growth and nipping out the tips of the stems will encourage the plants to bush out. You can also cut whole stems off and put them in a glass of water till you need them.

Watch out! 

There are mainly two problems with Mint, rust and a beetle! 

Mint rust can be spotted by looking for swollen stems with orange spots on the leaves. Affected plants should be disposed of as it will spread and remain in the soil for at least three years. Don’t plant other mints, tarragon or chives in that same spot. 

Mint beetles are shiny and green and their round black larvae feed on the foliage of mint plants in summer. Large populations can severely damage plants so both adult beetles and larvae should be removed by hand.

Pro Tip

Leave the plants to flower for the beneficial insects, and cut back afterwards for a new flush of fresh leaves for autumn picking.

Nerdy facts

The botanical name of Mint is Mentha and in Britain there are ten species that are indigenous or naturalised. Although mint is often considered invasive, it is an excellent plant for our precious pollinators!

Recommended Varieties

There are more than 120 varieties of mint to choose from but here are a few to try! 

‘English Garden Mint’ is a bright green, medium-strong flavoured variety that is good for salads and mint sauce.

‘Apple’ is a strong growing, traditional cottage garden mint with a mild and fruity flavour. 

‘Chocolate’ produces brownish leaves that taste like after-dinner mints and is non-invasive. 

‘Lime’ is just as the name suggests, lime flavoured. It has dark green to purple leaves and is non-invasive. Fantastic in summer drinks and in a gin and tonic! 

‘Moroccan’ is excellent for mint tea at the strongest end of the flavour spectrum. It also goes well with lamb and in vinegars.