Watsonia Plant Growing & Care Guide for Gardeners

Article by Dean Ravenscroft, Ph.D. - Updated 25th Oct 2023

In this Gardener's HQ guide, we'll explore cultivating Watsonia plants in your garden, indoor spaces, and other settings.

Bugle Lily and Bulbil Bugle-lily: Cultivation & Garden Use

Watsonia plants grow from hardy bulbs. They range from 30 cm to 1.7 m (12 to 70 inches) in height. Their foliage resembles sword shaped leaves.

Watsonia by faeparsons.

Watsonia bloom towards the end of summer. When in bloom, they carry trumpet shaped flowers on spikes. The flowers may be red, pink or white.

Watsonia borbonica by Enez35.

Although usually known by gardeners by its genus name Watsonia, other commonly used names for these garden plants are the Bugle lily, and Watsonia Iris.

Are you on the hunt for some good companion plants to help complement your Watsonia's striking foliage and blooms? Then try growing them alongside grasses such as Pennisetum and Miscanthus, spiky flowered Salvia plants, delicate Gaura wandflowers, and Kniphofia Red Hot Poker plant.

How to Grow Watsonia Bugle Lily

It is easiest to grow Watsonia using bulbs (corms) purchased from a garden center or that someone has passed on to you. These bulbs should be planted at a depth of about four inches (10 cm) in the autumn.

If you are planning on growing from seed, then be aware that it will usually take about three years until they will first flower. The seeds should be sown at a depth of 1/10th inch (3 mm) in the autumn.

Plants should be spaced about one foot (30 cm) apart, into a sunny part of the garden. This location should have a moist soil that has been enriched with manure.

In colder regions, you may prefer to start them off indoors, do so about two months in advance. They should take from one to six months to germinate at 54 to 64°F (12 to 18°C). Transplant seedlings outdoors following the last frost of spring.

Caring for Watsonia

As Watsonia plants are quite large and have large blooms, they should be staked once they have become established, especially in windy locations.

They are hungry, thirsty plants. So supply them with a liquid fertilizer monthly when they are actively growing. Keep them well watered, especially during dry spells.

If you are growing in colder areas then you'll need to apply a layer of mulch around the base of the plant to help protect them from winter temperatures. This is also good for maintaining soil moisture. Ideally apply a mulch that is 2 to 3 inches (5 to 8 cm) thick, and avoid direct contact with the stems.

Be on the lookout for pests such as Red spider mites and aphids. These can usually be prevented bu using insecticidal soap or neem oil.

If you require more plants then propagate by division of the cormlets at the end of autumn, once the flowering cycle has completed.

Commonly Grown Watsonia Species Photographs and Plant Identification

Watsonia borbonica

Watsonia borbonica (Cape Bugle-lily), photograph by Forest and Kim Starr; CC.

Close up of Watsonia Borbonica flower, picture by Bernard DUPONT; CC.

Common Questions

How many members does the Watsonia genus have?

The Watsonia genus, often known as Bugle Lily, comprises around 52 species.

Do members of Watsonia make a good garden or landscaping plant?

Yes, Watsonia species are known for their tall, impressive flower spikes. They're perfect for borders or cutting gardens.

Which Watsonia species are most frequently grown by gardeners?

Watsonia borbonica and Watsonia meriana, also known as Bugle Lilies, are popular choices for gardeners.

Are members of the Watsonia plant genus fragrant?

While visually appealing, Watsonia species are not particularly known for their fragrance.

What is the perfect location to grow Watsonia?

Watsonia thrives in full sun with well-drained soil. They're excellent for borders or cutting gardens.

Is Watsonia invasive in the USA, if so in which states?

Currently, some species of Watsonia are considered invasive in parts of California. Always refer to local regulations for accurate information.

How do I remove Watsonia plants from my garden?

To remove Watsonia, dig up the entire plant including the corms, ensuring all plant material is removed to prevent regrowth.

Summary

The Watsonia plant genus belongs to the Iris family, Iridaceae. Native to South Africa, this genus includes approximately 52 species of perennial plants.

Watsonia prefers full sun and well-drained soil. They are typically grown from corms, which should be planted in autumn. These plants are known for their tall spikes of brightly colored, trumpet-shaped flowers.

I hope that you enjoyed this guide on how to grow Watsonia plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Crocosmia, Gloriosa, and Schizostylis plants.