Canterbury
Will the real marigold please stand up, says Mary Lovell-Smith.
Or do you picture the simple sunny beauty of Calendula officinalis with its neat tight rows of petals? I recently posted a photo of a calendula and one of a tagetes on Facebook, and asked friends which one represented a “marigold” to them.
More than 60 replied, most gardeners. About 35 were women over the age of 50; 21 were women under 50; and there were 10 men of all ages. Two to one, responders chose the calendula rather than the tagetes; with a higher percentage of younger gardeners choosing tagetes.
This divergence of opinions illustrates the problems with plant nomenclature. Linnaeus would be turning in his grave at the casualness with which his carefully considered system is often ditched in favour of common or popular names.
As with the marigold, a common name can embrace two quite different plants, and even steal the name from the its original owner.
Marigold has only ever been a common name, never a botanical one.
It is often prefixed by one of the following: pot, English, African and French.
Pot and English refer to calendulas, which are presumed native to southern Europe. So long have they been in cultivation, however, that their origins are unclear.
When Shakespeare spoke of, in The Winter’s Tale, “The marigold, that goes to bed wi’ the sun. And with him rises weeping”, he was referring to the calendula – not the tagetes – that would not have long been seen in England.
The African and French marigolds, Tagetes erecta and Tagetes patula respectively, are natives to Mexico and Central America, and did not appear in Europe until well after the Spanish conquered the Aztecs in 1521.
Tagetes were among the many strange new plants taken back to the Spanish monasteries then, before eventually spreading to gardens in the rest of Europe and beyond.
New Zealand’s seed merchants today differ in their definitions of marigolds. Kings Seeds lists cultivars of both the aforementioned tagetes, plus a Tagetes tenuifolia and a Calendula officinalis under marigold. Egmont Seeds and Yates list only tagetes, giving calendula a listing all on its own.
Some may not care, but to a pedant, such confusion over names is simply annoying.
To a serious gardener, it can be frustrating and confusing, and in a worstcase scenario, even dangerous. As well as being decorative in the garden (and an excellent cut flower), Calendula officinalis has many culinary, cosmetic and medicinal uses. The petals add colour and an aromatic bitterness to dishes, from rice to salads, omelettes and even cheeses. They have long enjoyed a reputation for healing the likes of burns, nappy rash and wounds. Taken as a tea, the plant is said to be good for the complexion as well as soothing stomach ulcers and digestive troubles. On the other hand, if ingested, the Tagetes species may cause mild stomach upset and the sap irritate the skin. Cat and dog owners have to be wary of their pets eating it – it can cause excessive salivation, swelling, vomiting, or rashes.
However, both are useful to gardeners. Calendula repels whitefly and aphids, and attracts beneficial insects such as ladybirds, lacewings and hoverflies. Having a long flowering period, it is a useful pollinator, being attractive to the likes of nectar-loving butterflies and bumblebees. It concentrates sparsely distributed nutrients from the soil, making it not only an excellent companion to almost any plant but a valuable addition to mulches and the compost heap.
Tagetes also deter the likes of whitefly and carrot fly, and will confuse cabbage white butterfly by overpowering the host plant’s smell. The chemicals extruded from their roots repel and kill unwelcome nematodes such as eel worm. These roots also encourage the growth of beneficial mycorrhizal fungi.
Both are pleasingly easy to grow. As short-lived perennials (or annuals in colder climes), calendulas can flower for months on end, preferring sun and free-draining soil, but they do tolerate most positions and soils. Prolific selfseeders, they’ll stay in your garden for years if you let them.
The annual tagetes likes full sun and free-draining soil, but needs some deadheading to prolong flowering. ✤