The Succulents form a very large, world-wide group of plants from the low rainfall tropical and subtropical areas of the world, particularly from the Americas and South Africa. They have thick, fleshy parts in which the internal tissue consists of large air-filled cells which are capable of storing moisture. This enables them to withstand long periods of drought. There are three types depending on whether the leaves, or the stems or the roots are the storage organs. Most succulents have a leathery "skin" and many possess either a waxy coating or dense hairs to help reduce moisture loss in the hot, dry conditions.
Hunter Region Botanic Gardens features the largest Succulent Garden in Australia. Most of the plants in the Succulent Garden are exotic, and consist of representatives from the following families:
- Cactaceae, eg genus Cactus Cacti are confined to the Americas. They are perennial herbs in which the leaves have usually been reduced to spines and the green fleshy stems (called cladodes) act as water storage organs and carry out the normal photosynthesis process of leaves.
- Agavaceae, eg genera Agave, Sansevieria
- Asclepiadaceae, eg genus Stapelia
- Crassulaceae, eg genera Crassula, Echeveria
- Asteraceae, eg genus Senecio
- Euphorbiaceae, eg genus Euphorbia
- Ficoidaceae, eg genera Conophytum, Lithops
- Fouquieriaceae, eg genus Fouquieria
- Liliaceae, eg genera Aloe, Gasteria, Haworthia
- Portulacacaeae, eg genus Anacampseros
Many of the plants growing here are very rare, and some are extinct, in their native habitats.
Features of the Succulent Garden
- The Aloe collection is a unique collection in Australia consisting of approximately 90 species which are native to Africa and Madagascar.
- The Golden Barrels (Echinocactus grusonii) occur naturally in southern USA and Mexico. The garden has a number of these spiky plants which may not flower until they are 20 years old. They may live to 100 years and grow to one metre in diameter.
- The Opuntias. Opuntia is the largest and most widespread genus of the Cactaceae, growing from Canada to Patagonia. They are easily recognised by their large disc-like "stems". In times of drought, the large Opuntia ficus-indica is chopped up for cattle feed.
- The Euphorbias. This group of spined succulents may range in size from small plants to tree size and most contain a caustic white milky sap which is poisonous. The flowers are tiny and usually insignificant, however, their attraction lies in the unusual shapes of the plants. Southern Africa is their principal habitat.
- Pony tails (Nolina recurva) are native to Mexico, and as can be seen by the larger 40 year old plant in the garden, can grow to a large size. The large bunches of small pink flowers appear when the plant is quite large.
- Three Dragon's Blood trees (Dracaena draco) which are native to the Canary Islands. The stems exude a red resin when rubbed or damaged - hence dragon's blood. This resin was considered to have magical properties by the inhabitants of the islands.
What is a succulent?
Succulents have water storage tissues in their leaves, stems or roots and are able to withstand extended periods of drought.
Where do they come from?
With few exceptions, cactus come from North and South America. The remainder of the succulents come from around the world, with southern Africa having the greatest number. Australia has only a few species in the Aizoaceae and Chenopodiaceae families.
What growing conditions are necessary?
Conditions vary but as a general rule they require a bright sunny position in a well drained soil such as a mix of river sand and potting mix.
How long do they take to flower?
Some seed grown plants will flower in their second year, while others may require 20 years or so. However, once they commence flowering they should do so annually.
Why did my succulent die?
This is normally due to over watering. Water once a week in summer, and do not water excessively or during winter or cold weather.
Do they need fertilising?
Yes. Use a slow release fertilizer in moderation during summer.