Aloe thraskii (dune aloe) is a large, attractive, single-stemmed plant with giant, thorny-edged leaves that curve outwards and downwards, like fleshy arches. The sturdy inflorescences with their racemes of bright yellow flowers appear in June and July. This is a lovely plant for coastal gardens.
Sometimes we ignore or neglect them, but when the fiery flowers of the aloes appear, we cannot get enough of these plants. Nowadays nurseries stock many new aloe hybrids, and they bloom in so many stunning colours that even the most selective of colour connoisseurs is sure to be satisfied. From the small, humble varieties to the stately Aloe ferox and Aloe ‘Rex’, the plants in this genus are now high fashion and claiming their rightful place in our gardens.
South Africa has a wide range of indigenous aloe species, ranging across the summer and winter rainfall regions. There are also many new forms and varieties that have developed as a result of natural crossbreeding, a process aided and abetted by the birds and bees that visit the flowers for the nectar.
Aloe collectors (and there are many) also contribute to increasing the number of varieties available by walking between the plants during flowering season, and selectively pollinating them as they go. They practise endless patience and superhuman dedication and make sure they know exactly ‘who may court whom’. After years of careful monitoring they are eventually able to harvest seeds that produce modern aloe hybrids with lovely forms and superb flowering abilities.
Aloes have leaves that are arranged in a rosette around each stem and branch, and superficial root systems that continuously renew themselves. For every new leaf a corresponding root develops, but if that leaf dies the root remains as an anchor. The rosette shape of the leaves forms a natural funnel that channels water down to the roots, where it is absorbed immediately. It can be said that aloes take care of irrigating themselves, which is why they don’t often need a gardener’s help in that regard.
Aloes (with a few exceptions) are protected plants and may not be collected from the veld without the permission of the landowner or the necessary permit.
When do they bloom?
There are both winter- and summer-flowering aloes, so between them and all the lovely new hybrids there should always be at least one in bloom.
Most suitable climate
If you take into account the natural habitats of our indigenous aloes, it is apparent that they can be grown almost throughout the country. However, although they are often described as ‘exceptionally hardy’, they are not resistant to heavy frost and bitter cold. Most can tolerate light morning frost, but in areas that suffer from anything harsher, they should be protected with a frost blanket.
What they need
Location: full sun, even in the hottest regions. Rockeries were the traditional spots for aloes, but nowadays they are planted in more prominent places in the garden. They are exceptionally pretty between ornamental grasses, and as accent plants in pots and formal urns.
Soil: sandy soil, and practically any other soil, will work, as long as there is good drainage. Nurture your aloes by enriching their planting holes with liberal quantities of good compost. They also like organic mulch consisting of coarse compost, dry grass cuttings and decayed leaves (but the layer must not be too thick). When potting aloes, use a commercial potting-soil blend suitable for succulents, or sandy soil with compost mixed into it.
Water: aloes are very drought resistant and when it is purely about survival they can get by with very little water. To produce healthy, lush growth and lots of flowers during the flowering season, they need regular water during the summer months. Water young plants regularly during the first few weeks after planting in order to keep the soil moist until they are established. Potted aloes need to be watered at least once a week, provided the soil feels completely dry, but even with pots rather give too little water than too much.
Fertilizing: renew the mulch during early summer. You can also sprinkle a handful of organic fertilizer on the soil around the aloes.
Watch out for this
Insects such as aphids and snout beetles sometimes attack aloes, and they occasionally fall prey to fungal diseases, such as rust, especially if they are growing close together. Spray the plants with a systemic insecticide to stop the sucking insects in their tracks.
Make sure that the poison runs into the growth points between the leaves as well. A fungicide with a copper base can help to control diseases such as rust, which are a nuisance in humid climates.
Get more value
If you obtain an aloe cutting without roots, for example a branch of A. arborescens or A. barberae, place it on a piece of newspaper in the shade for about two weeks to let the wounds dry out. After that, simply push it into sandy soil, such as coarse river sand, to let it take root (you can dip it into commercial hormone rooting powder first). Stemless aloes produce many runners – simply divide them and then replant.
Generally, aloes grow easily from fresh seed sown during spring. Use a free-draining seedling mixture (available at nurseries) and keep the mixture damp until the seeds have germinated and begun to grow well. Treat the young aloes with a fungicide.
In a nutshell
* Tough, water-wise plants.
* Low maintenance.
* Ideal collectors’ plants.
* Many species bloom in winter, providing colour when the landscape is bleak.