Planting up a succulent display
In March 2010, I was asked to design a dry tropical display for one of Kew’s iconic beds for the summer. I saw this is as a great opportunity to show the public the intriguing forms of some of our cacti and other succulents. These specimens are normally kept “behind the scenes” in the Tropical Nursery. The bed is situated at the north end of the Broadwalk, to the west of the Orangery; this high footfall area would allow many of Kew’s summer visitors to appreciate these unusual and often overlooked plants.
The circular bed at the north end of the Broad Walk
I hand-picked the individual specimens to ensure that there was a good selection of forms, shapes and sizes. Many succulents have a globular or hemispherical shape; this maximises the volume available in which to retain water. I chose to have a clump of one my favourite cacti species: Echinocactus grusonii. It is often called the “golden barrel” or, more unkindly, “mother-in-law’s cushion” due to it’s striking round shape and bright yellow spines.
It was the focus of an intensive rescue effort in Mexico in the 1990s when its primary habitat was due to be flooded after the construction of a major dam*. As such, it is one of our “conservation plants”. Few remain in the wild today, although conservation work in botanic gardens and nurseries in Mexico and the US has made this cactus one of the most popular in cultivation.
A clump of "golden barrel" cacti in the succulent display
I transported the plants with help from a Kew Diploma student and an apprentice. Handling cacti can be tricky, so we used a tractor, coir matting, bamboo canes and even barbeque tongs to protect ourselves from the sharp spines. We also wore gloves, leather gauntlets and safety goggles. Before planting, we laid out all the plants on the bed to get the position just right (I realised that I wasn’t going to be too popular if I kept changing my mind about their positioning).
The Dry Tropics team apply the gravel
To prepare the bed, we put down a hard-wearing, polypropylene groundcover sheet. This helps suppress weeds, and also separates the soil from the gravel that we would use as a top dressing. We plunged a few of the larger, more upright specimens straight into the ground while still in their pots. These included the 1.5m high Echinopsis and the tallest Haageocereus x espostoa. We planted the rest of the plants directly into the topsoil of the bed. Once we had finished planting, we shovelled a thin layer of gravel across the surface, which provided a great foil to their structural forms.
The completed display in June 2010
The succulents seem to have responded really well to the prolonged warm summer and wet August, colouring up nicely, producing extraordinary flowers and putting on lots of new growth. As autumn approaches, we will return them to the protected conditions of the nursery before colder, wetter weather can do them any damage.
This display will end on the 19th September. The bed will then be returned to a more traditional bedding scheme in keeping with the Palm House parterre for winter. Given the chance to create another dry tropical display, I would use Echeveria cante, Agave attenuata and the stunning Agave bracteosa. This spineless and toothless plant has bright-green foliage and is often mistaken for an Aloe.
Not only should it turn a few heads, I might be a bit more popular with the team for choosing more tactile plants.
* Reference: Echinocactus grusonii, United States Botanic Garden, no date, http://www.usbg.gov/plant-collections/conservation/Echinocactus-grusonii.cfm