From our perspective as Desert Rose plants (Adenium obesum), our watering needs are a direct reflection of our internal biological rhythms, which are dictated by the seasons. Understanding these needs is crucial for our survival and flourishing. We are not like many other houseplants; our thick, caudiciform stem is a built-in water reservoir designed for arid environments. Here is a detailed explanation of how you can best support us throughout the year.
Summer is our time to shine. With longer daylight hours and intense warmth, our metabolic processes are running at full capacity. We are actively photosynthesizing, pushing out new leaves, and, most importantly, working to produce our beautiful flowers. This vigorous activity requires a consistent supply of water to transport nutrients and maintain turgor pressure in our cells. During this period, our internal water reservoir is being used and replenished regularly.
The best practice is to water us thoroughly when the top inch or two of the soil feels completely dry to the touch. Provide a deep, generous drink until water flows freely from the drainage holes. This ensures the entire root ball is moistened and encourages our roots to grow deep and strong. It is then essential to allow the soil to dry out significantly before the next watering. We despise having our roots sit in constantly soggy soil, as this will lead to root rot, a condition that is often fatal for us. In the peak of summer, this might mean watering once a week or even more frequently, depending on the heat and humidity.
As the intense heat of summer wanes and daylight shortens in autumn, or as we emerge from our winter rest in spring, our water requirements are in a state of flux. You must observe us carefully. In spring, as you see new buds forming, you can gradually increase the frequency of watering to support this new growth. Conversely, in autumn, as growth slows and we begin to prepare for dormancy, you should start to extend the periods between waterings. The soil should be allowed to become almost completely dry throughout the pot before you consider giving us another drink.
Winter is a time of rest for us. With cooler temperatures and significantly reduced light levels, our growth comes to a near-complete halt. Our metabolism slows dramatically to conserve energy. During this dormant phase, our need for water is minimal. Our leaves may yellow and drop, which is a natural and expected process; it is our way of reducing water loss through transpiration.
Overwatering during this time is the single greatest threat to our health. Our roots are largely inactive and cannot absorb much moisture from the soil. If the soil remains wet, the roots will suffocate and rot. The best practice is to water very sparingly. Allow the soil to become bone dry throughout the pot. In many cases, a light watering every three to four weeks, or even longer, is sufficient. The goal is merely to prevent our main caudex stem from shriveling excessively. A slightly wrinkled caudex in winter is normal and far preferable to a soft, mushy one caused by rot.
