How to grow bee balm

Bee balm (Monarda didyma) is an herbaceous perennial plant in the mint family that’s easy to grow and care for. Its vibrant summer flowers and medicinal properties make it a valuable plant for humans and wildlife. It's also commonly known as ‘bergamot plant’, not to be confused with the completely unrelated citrus fruit whose peel is used to flavour Earl Grey tea.

It’s native to North America, where it was traditionally used by Native American tribes for medicinal purposes. The plant was used to treat a variety of ailments, including sore throats, colds and fever. Today, bee balm is still used in herbal medicine, and its leaves can be used to make a tea that is believed to have anti-inflammatory and antiseptic properties.

How to grow bee balm

Growing and caring for bee balm in your own garden is easy. It’s a great plant choice for gardeners looking to attract wildlife to their garden, while also enjoying the beauty of its bright-red, pink or purple flowers that are like magnets to pollinators.

Where to grow bee balm

Bee balm prefers full sun but will grow in partial shade, and requires moist but well-drained soil. In terms of climate, bee balm is a hardy plant that can withstand temperatures as low as -15°C. It’s also reasonably drought resistant once established, making it an excellent choice for gardens in areas prone to dry spells and as part of a ‘water-wise’ garden.

How to plant bee balm

When planting bee balm, choose a location in full sun or partial shade with moist but well-drained soil. Dig a hole that’s slightly larger than the plant's rootball and gently loosen the roots before planting. Bee balm is prone to powdery mildew, so space the plants approximately 45cm apart to allow good air circulation. Water well after planting and keep the soil moist while the plant is establishing.

How to care for bee balm

Bergamot is a low-maintenance plant that requires little care once established. Water the plants regularly during dry spells and mulch around the base to help retain moisture. Deadhead the flowers regularly to encourage continued blooming and prevent the plant from going to seed too quickly. In terms of position, bee balm does best in a spot that receives a bit of afternoon shade – this will ensure it's protected from the very harshest sunlight in midsummer.

Like many perennials, when grown from seed bee balm will only bloom properly from its second year of growth; before then it will be focusing its energy on producing a strong root system.

How to prune bee balm

There are two main times of year to cut back or prune monarda. The most important of these is in autumn when the top growth has died back. Either cut the stems the whole way down to the ground so the new growth in spring has plenty of room to grow through, or just cut back to about 10-20cm and then follow up by cutting the stems down to the ground when new growth starts appearing in spring. The first of these cuts will make the plant less susceptible to mildew through the cold season, while leaving plenty of cover for insects to overwinter within. Alternatively leave the plant altogether in autumn and just cut back to the ground in spring, so birds can enjoy the seedheads through winter.

The other good time to intervene with your secateurs is in late May, cutting the whole plant back by about a third with a 'Chelsea Chop'. This will slightly delay flowering but help the plant to be more compact and branching, and less in need of support come midsummer.

Whatever the time of year, it's always a good idea to remove any dead or diseased foliage to prevent the spread of pests and diseases.

While bee balm is not considered an invasive species in the UK, it's always a good idea to monitor your garden for plants that may be spreading beyond their intended area. If you notice that it is spreading too much, prevent it from becoming a problem by dividing the plant and planting it in a new location.

How to propagate bee balm

Monarda can be relatively short lived and spreads quite strongly, so it's a good idea to lift and divide plants every few years and replant using the more vigorous, younger divisions. To divide bee balm, dig up the plant in the spring and carefully separate the roots into smaller sections and then replant these at the appropriate spacing.

To grow from seed, sow indoors from mid spring, and transplant outside once the risk of frost has passed and the plants are large enough to cope with garden conditions.

Alternatively, you can propagate bee balm from cuttings taken from existing plants. Simply take a cutting from a healthy stem in spring, remove the lower leaves and plant the cutting in a pot filled with moist but free-draining compost. Keep the cutting in a warm and slightly humid environment, with the compost reasonably moist, until it has established roots. The cuttings can then be moved on to larger pots and grown on until they are big enough to plant out.

Pests and diseases

While bee balm is a relatively pest-resistant plant, it can still be susceptible to certain pests and diseases. Common pests that may affect it include aphids and thrips. Both of these species are at the bottom of the food chain, and are naturally controlled by birds and certain wasps. However, if they appear in significant numbers you may want to consider spraying them with a mixture of water and washing-up liquid or using an insecticidal soap spray. Bear in mind that, along with aphids, you may also be spraying natural predators like ladybirds and hoverfly larvae. The best way to avoid this is by spraying on a dull day, as these beneficial insects will be most active in bright sunshine.

Fungal diseases, such as powdery mildew, can also affect bee balm, particularly in hot and humid conditions. To prevent these, avoid overhead watering and ensure that the plants have good air circulation. Also ensure that plants are not subjected to too much drought. Alternatively consider a variety that is known for being more resistant to powdery mildew.

Bee balm varieties

Bee balm comes in a wide variety of colours, including red, pink and purple. Popular varieties include:

Monarda 'Cambridge Scarlet' – a popular variety with bright red flowers. Height x Spread: 90cm x 45cm

• Buy Monarda 'Cambridge Scarlet' from Crocus

Monarda 'Prärienacht' – this has deep-purple flowers and dark foliage. H x S: 90cm x 45cm

• Buy Monarda 'Prärienacht' from Burncoose

Monarda 'Jacob Cline' – has large, bright red flowers and a strong, minty fragrance. H x S: 90cm x 75cm

• Buy Monarda 'Jacob Cline' from Dorset Perennials

Monarda 'Squaw' – an attractive, pink-flowered variety. H x S: 1m x 45cm

• Buy Monarda 'Squaw' from Farmyard Nurseries

Monarda ‘Bubblegum Blast’ – a compact variety with bright-pink flowers and aromatic dark-green foliage. H x S: 60cm x 60cm

• Buy Monarda 'Bubblegum Blast' from Ashcroft Perennials