CHOOSING HARDY CACTI AND SUCCULENTS FOR GROWING OUTSIDE
In the cool regions of northern Europe, but where temperatures rarely fall below freezing, many cacti and succulent species will thrive outdoors in troughs, raised beds and pots - provided the plants are raised above ground level to allow water to drain away freely. A warm sheltered position – such as a walled south-facing corner, or a covered patio or balcony where the plants can more easily be protected from rain - will provide the ideal environment.
The foliage shapes of Sedum and the neat rosettes of Sempervivum can be used to form a contrast with the leafy forms and brilliant blooms of Lewisia species and cultivars, the green-flowered Echinocereus viridiflorus, hardy Umbilicus, and the summer blooms of hardy Lampranthus. Other species, such as the Agave parryi, which has symmetrical rosettes of plump, grey-green leaves, or Opuntia polyacantha, with its brilliant display of yellow flowers, make striking focal points if they are planted in mixed displays or on their own in large bowls.
In warmer climates, there is a much greater scope for growing cacti and succulents outdoors in containers. In large pots, groups of plants that flower at different periods and have striking foliage forms such as the purple leaved Aeonium arboretum ‘Schwarzkopf’.
Aloe barbadensis which has yellow flowers and the red flowered Crassula falcata will provide structural interest all year round, and give a succession of attractive blooms throughout the warmer months.
Where temperatures do not consistently fall below 13 degrees Celsius, any dwarf cacti, such as species and cultivars of Gymnocalycium, mammillaria, and Rebutia, make fascinating displays of form and texture in outdoor bowls and troughs in the garden. These dwarf, cluster-forming species also give a magnificent display of vibrant colour that will last for many weeks on end during the summer.
. The key thing is to provide the right conditions as the great majority of cacti and succulents need high light levels, warmth and good ventilation to thrive - although some, the leafy succulents in particular, may need protection from direct sun during the summer to avoid leaf scorch.
There is one important group of cacti however that requires shady conditions, or at least filtered light. These are the epiphytes that come from the humid and shaded rain forests of South America such as the Christmas cacti – Schlumbergera bridgesii and Rhipsalidopsis gaertneri.
AGAVE PARRASANA - The Cabbage Head Agave