A Calendar of Succulents – Agaves
Agaves are my chosen plant this month – a genus of very beautiful (and somewhat spiteful) plants.
Native to the sub-tropical and tropical Americas, where they are important food, sisal and drink crops, and now widely naturalized in many parts of the world, including the Mediterranean and some southern coastal areas of the UK, these leathery-leaved, rosette forming succulents are commonly known as the Century Plant because of a myth that they flower only once every hundred years. This is erroneous, as the plants will flower when mature (with different species this ranges from 6 to 40 years); when a magnificent flower spike will emerge and reach many metres high in some cases, before panicles of lily-like flowers unfold. Most species will die after flowering, exhausted by the energy taken to produce such huge inflorescence.
Many agaves will grow to an enormous size (in excess of 4 or 5 metres across) making them unsuitable for any but the largest and mildest of gardens in the UK, but there are also a good number that are much smaller and these can make attractive potted specimens. One of the most pleasing and distinctive aspects of this genus is the impression left on each leaf by the tightly rolled inner leaves, which are revealed as the plant grows. The more toothed the leaf margins, the more intricate the impression that is left – a beautiful example is Agave impressa, which has bud impressions that look as though they have been outlined in white paint. Leaf colour can vary from grass green through steely blue to pearly white or grey; and leaf shape from needle-fine to broad. Some species have smooth leaf margins, others are saw or shark-toothed while others still have contrasting leaf margins or even have curling fronds along their leaf edges (Agave filifera, for example). There are also lots of variegated forms – many of these are stunning hybrids originating from Japan, which fetch high prices for the more collectable forms.
Unsurprisingly, given their native environment, agaves are only half-hardy and would need protection in severe winters. They can survive in coastal areas and where a microclimate allows and provided there is also excellent drainage. Protecting the plants with straw stuffed into the centre and then wrapping the plant with fleece can help and there are some species that display greater hardiness than others. These are plants that demand a bold but simple container. Larger specimens look fantastic in large corrugated metal or galvanized containers However, should you decide you would like to grow these plants, I would caution against if you have children as the terminal leaf spines can cause very nasty injuries. If you walk into an agave on the edge of a border, you’ll remember forever where it is. Folklore has it that the Aztecs used to sacrifice people by throwing them off cliffs onto clumps of waiting agaves below….
Top left: Agave victoria-reginae (to 60cm wide)
Above right: Agave Parryi ‘Cream Spike’ (to 1m wide with the flower spike reaching 5m!)