The desert rose is an extremely pretty and undemanding ornament for the home windowsill – and yet rather a rarity among amateur gardeners. We have compiled a list of everything you need to know about this African beauty.
Origin
The desert rose, botanically Adenium, is actually not a rose at all – it belongs to the dog family. It owes its beautiful name to its rose-like flowers, which delight with their splendor even under hot, dry conditions. This is because the plant is adapted to such environmental conditions – its habitat is semi-arid, i.e. a climate characterized by long dry periods. Specifically, the desert rose is native to the steppes of Africa and Arabia.
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What location is suitable?
For cultivation in our latitudes, this means that the desert rose needs a sunny, warm location. It thrives best in a bright spot on a windowsill and can conveniently handle intense sunlight and heat. However, you should turn it a little from time to time so that it does not grow at an angle towards the light-facing side. In the summer, you can and should also put it outside, because here the light yield is in any case greater than in the room. In winter, you must ensure that its ambient temperature does not fall below the 10°C mark.
Desert rose location rules to remember:
Place warm and sunny
Turn occasionally for balanced, straight growth
Can/should also be placed outdoors in summer
No ambient temperatures below 10°C in winter
Growth
The desert rose is classified as a shrub, but it grows as a stem succulent. It forms a caudex, a strongly woody trunk, which makes its habit rather tree-like. The caudex is used for effective, long-term water storage and makes the desert rose a real plant camel, because it can easily survive long periods of drought. The water storage capacity makes the trunk very thick and the thickening at the base makes for a striking overall appearance.
In the wild in its native habitat, the trunk of the desert rose reaches a diameter of up to 2 meters. In height it reaches up to 5 meters, but in Central Europe it remains smaller because of the lower light and heat supply. It grows very slowly and reaches a Methuselah-like age of several hundred years.
An overview of the growth characteristics of the desert rose:
Stem succulent with water-retaining caudex stem.
Thus striking appearance and very drought resistant
Reaches up to 5 m height and 2 m trunk diameter in the wild
Slow growth
Reaches several hundred years of life
Flower
The desert rose owes its name to the attractive, pink to reddish, white or violet cupped flowers. Their shape also indicates their close relationship to the oleander. They are terminal, five-toothed, and tubularly fused, intensifying their color outward. With a diameter of up to 5 centimeters, the flowers are relatively large. They appear in late spring to early summer, around April to July.
The foliage leaves of the Desert Rose are also quite attractive with their fingered texture and rich green color, and their leathery texture adds an exotic touch to the plant in addition to the grotesque looking caudex stem. The leaves are clustered at the shoot ends and grow to about 5 to 15 cm long. The shape of the individual leaves is inversely ovate and with entire margins. In its native area, the desert rose is almost evergreen, but in this country it sheds its leaves during the winter dormancy.
Watering desert rose
As a stem succulent, the desert rose makes watering easy for the amateur gardener. Because it can hoard so much water in its caudex, you can forget about it once in a while or go on vacation for a few weeks without organizing a watering substitute. In general, it can manage with little water, but waterlogging is much more critical than a lack of water. It can lead to root and stem rot and must be avoided at all costs.
Over the winter, you almost do not need and should not water at all – this would be contrary to the given lack of light. After the winter break, you should also only gradually accustom them to more water again.
To remember:
Desert rose needs little water
Can survive long periods without watering due to caudex trunk
Avoid waterlogging at all costs
Hardly any watering necessary in winter
Wintering
The dwindling light supply of our Central European winter inevitably means a dormant period for the desert rose culture. However, you should not put it in the dark, but leave it in a bright window place. In accordance with its vegetative rest, it also needs cooler temperatures in winter, although these should not fall below 10°C. A good location is a windowsill in a room that is not too warmly heated. It is important to water little to not at all – too much vegetative drive by watering can prevent flowering the following spring and summer!
Overwintering rules for the desert rose:
Place slightly cooler, but bright
No temperatures below 10°C
Little to no watering
Fertilize desert rose correctly
Throughout the growing season, you can fertilize the desert rose a little, but at most every 2 weeks. To do this, use a fertilizer with balanced levels of potassium, phosphorus and nitrogen.
Loses leaves
Although the desert rose is almost to completely evergreen in its native country, in our country it loses its leaves during the fall. This is quite normal as far as it goes, as it needs a resting period in the face of dwindling light. So when it comes to leaf shedding in October, you don’t need to worry.
However, if the desert rose sheds its leaves during the light-rich growing season, it is a cause for concern. In this case, different factors may be to blame. The most likely are the following:
Unfavorable location
Too fast change of circumstances after winter break
Waterlogging
Overfertilization
Unfavorable location
Site conditions are unfavorable for the desert rose if they are too dark or too drafty. Always make sure that the African plant gets lots and lots of sun. It also does not like drafts at all.
Too fast metabolism after the winter break
According to its slow metabolism, the desert rose must be gently and slowly accustomed to the increasing light and water supply after the winter break. Avoid a radical start to the vegetation phase by placing it immediately in full sun in spring and trying to force it into budding and flowering with heavy watering. Instead, it is better to place them in a slightly brighter spot at first and start watering very gradually.
Waterlogging
A substrate that is too wet is quite bad for the desert rose. Always make sure that the substrate is not permanently wet and remember that the plant stores enough water in its stem. Root and stem rot can not only cause temporary leaf drop, but will permanently damage the plant.
Over-fertilizing
You should also not over-fertilize the desert rose. As a slow-growing steppe plant, it only needs a small amount of fertilizer at intervals of about 14 days during the growing season. Too much or too aggressive fertilizer can easily burn the desert rose.
Pruning the desert rose correctly
The chapter pruning is quickly checked off with the desert rose: Due to its slow growth and moderate branching, it does not need any pruning care at all.
If you want a special shape, perhaps in the direction of bonsai culture, you can of course work on the desert rose with cutting tools – but these should be well sharpened and hygienically clean. As a rule, it sprouts again well from pruning. However, under no circumstances should the caudex be damaged, as it is the water reservoir and elixir of life for the desert rose.
Repotting
When the desert rose has bloomed for the first time, it is recommended to repot it in the following early spring. For substrate, use a simple mixture of standard houseplant soil and a good amount of sand. In subsequent years, you will only need to repot the plant if the container becomes too crowded for it.
Propagation
You want to propagate your desert rose? This is relatively well possible by cuttings. This method is especially recommended because the desert rose grows so slowly. So, when growing cuttings, you don’t have to wait as long for a fully formed plant and for the first bloom. To do this, cut a medium-length shoot and put it in a pot with growing soil, which you place in a bright, warm place. For rooting, keep it evenly moist and cover it with foil if necessary.
Growing
Growing a desert rose from seed is a bit more time-consuming. However, patience pays off in more ways than one: Because unlike a cutting, a plant with a much better-developed caudex will develop from a seed – so you can expect a specimen with all the characteristic features. In addition, the desert rose seeds show a good germination capacity. The flower color will often revert to the original shade of pink – after all, with this method, unlike the cuttings variant, you do not get a clone.
When planting the seed, you must be careful not to place it too deep below the surface of the soil. At most, it should be covered by one centimeter. To germinate, place the seed pot in as bright and warm a place as possible and keep the substrate evenly moist. It usually also takes only a week to a week and a half for the seedling to show itself. When it reaches a height of about 10 centimeters, transfer it to a new pot with cactus soil and continue cultivating it according to the rules of care appropriate for the species. However, at least two years will pass before the desert rose grown from seed blooms for the first time.
Seed growing at a glance:
Preferable to the cutting method if a specimen with a fully formed caudex is desired.
High gelation rate due to good germination
Do not plant deeper than 1 cm into the soil
Warm, bright growing location
Duration until first flowering: at least 2 years
Diseases
Fortunately, the desert rose is quite resistant to diseases and pests. In the heated room, spider mites or mealybugs may occasionally appear. However, these are easily controlled by showering and, if necessary, spraying with an oily mixture or nettle broth.
Is desert rose poisonous?
The fact that desert rose belongs to the dog poison family says it all: it is poisonous, in all parts of the plant. In households with small children and animals that like to nibble on houseplants, it should be avoided at all costs. The milky sap of the plant is particularly poisonous, and in its native country it was also used as an arrow poison. The toxic cardenolides are highly concentrated and cause irritation of the mucous membranes, nausea and vomiting, cramps and circulatory disorders, and even life-threatening cardiac paralysis.
Varieties
The best known variety within the desert roses is Adenium obesum. In addition, 5 to 15 other varieties are distinguished, which are cultivated in this country as ornamental plants. Here is a small selection:
Adenium obesum
This most common species can be found in plant centers, but there are several subspecies with names like A. honghel, A. coetaneum or A. somalense. They have different colors of flowers from white to dark pink and have varying characteristics in appearance such as particularly corky bark or differentiated branching. It grows to about 3 feet tall in containers in indoor and outdoor cultivation and requires plenty of sun and warmth.
Adenium arabicum
This cultivar is quite close to Adenium obesum, but is considered best suited for bonsai culture among the desert roses. Its caudex is more pronounced than that of Adenium obesum and its leaves are particularly large. Their flower colors vary between pink, clear red, and deep purple with fire-colored centers. Adenium arabicum is often sold in seed form, giving bonsai enthusiasts a free range of design options.
Adenium multiflorum
Adenium multiflorum bears its most important characteristic in its name: its flowering is particularly rich and colorful, with colors varying between pink, pinkish tones or mauve shades depending on the specimen. The pleasure of flowering is further enhanced by a pleasant sweet fragrance. Its leaves are up to 10 cm long and glossy dark green. Unfortunately, however, this variety bears neither foliage nor flowers for most of the year. Overall, Adenium multiflorum reaches a height of between half a meter and 3 meters.
Adenium oleifolium
In European, this variety is called Ölbaumblättrige Wüstenrose and shows appropriate foliage with 4-13 mm long, olive-green leaves. In terms of size, it is the smallest desert rose variety with only about 30 to 45 centimeters of maximum growth height. Its flowers appear in pink, salmon to reddish tones.
Adenium swazicum
Adenium swazicum comes from Swaziland and is a small exception among the desert roses when it comes to location: it likes it quite a bit in partial shade and does not necessarily need as much sun as possible like the other varieties. Adenium swazicum also belongs to the smaller desert rose varieties with a maximum growth height of 45 to 60 centimeters. Its flowers appear a little earlier in spring compared to Adenium obesum and delight with intense pink to magenta hues.
