Agapanthus is as blue as a Sydney summer sky and just as reliable (give or take a la Nina year). But this old garden standby has a dark side: it’s on the weed watch list in NSW, where it has already invaded bushland in the Blue Mountains National Park and established itself, uninvited, on creek banks through Sydney’s suburbs.
There are two theories for its advance. Mature seeds can be washed into stormwater drains, and from there make their way into creeks and waterways. More egregiously, unwanted clumps have been dug out of gardens and dumped in bushland.
So it’s the behaviour of humans rather than agapanthus itself, which causes the problem. The solution is dead simple: never dump garden waste; cut off the flower heads off agapanthus when the flowers are finished and well before the seed matures; and choose modern less-fertile cultivars rather than the old blue or white species.
Agapanthus is a South African native, which was growing in Europe by the middle of the 17th century, having journeyed on the ships of the United Dutch East India Company. At that time it was called an African hyacinth and it didn’t take on its present name until the late 18th century when the director of the Jardin des Plantes in Paris, marvelled at the astonishing ball of flower, reached for his Greek dictionary and decided on “agape” meaning love and “anthus” meaning flower.
Australian colonial gardeners were early adopters of the “love flower” and by 1883, three varieties of agapanthus were being cultivated in the Melbourne Botanic Gardens. Garden writer Mrs Rolf Boldrewood described agapanthus “making showy plants in the open borders” in her 1893 publication The Flower Garden in Australia: a book for ladies and amateurs.
Wildly popular by the end of the 20th century, aggies are now looked down upon as common, but familiarity shouldn’t breed contempt. Agapanthus reigns supreme in a range of difficult roles, including stabilising steep banks and offering a low-care, low-water option up driveways, along fences and in pots. Its big globes of flowers herald summer and fill vases at Christmas time.
The former favourite showed a new benefit during the terrible bushfires of 2020. Gardeners noticed that a mass planting of aggies stalled the advance of grass fire. The key is the sticky sustenance in leaves and stem called mucilage. The mucilage of some plants is good for healing – like that of aloe vera for instance – but agapanthus mucilage is the opposite, and can cause skin and eye irritation.
On the upside all mucilage is full of water and acts as a fire retardant. This effect is especially useful when agapanthus are mass planted, and used in conjunction with other fire-safe planting choices.
As we reshape our gardens to adapt to climate change, agapanthus, with its drought-hardy, pest-resistant nature, might make it out of the sin bin and back into favour as the flower of love – as long as we all cut the dead heads off.
