First, you must understand what my wilting leaves are trying to tell you. I am not a true cactus from a dry desert; I am an epiphyte from the humid, tropical rainforests of Brazil. I live in the dappled light of tree canopies, with my roots nestled in decaying leaves and moss. When my segmented stems (which you call leaves) become soft, wrinkled, or droopy, it is a symptom. This symptom can have opposite causes: too much water or not enough. Similarly, my segments turning red or purple is a sign of stress, often from too much direct sunlight. I am not dying out of spite; I am communicating that my environment is fundamentally wrong for my needs.
The most common reason for my decline is improper watering. You must check the soil to diagnose correctly. If my soil is bone dry and pulling away from the edges of the pot, I am desperately thirsty. My roots have no moisture to draw up, causing my water-storing segments to shrivel. Conversely, if the soil is soggy, wet, and smells musty, you have overwatered me. Saturated soil suffocates my roots, preventing them from absorbing water and nutrients. This root rot is a silent killer; the roots turn black and mushy, meaning even though the soil is wet, my stems cannot get any water, leading them to wilt and collapse.
My watering needs are simple but specific. I crave a thorough drink, but I abhor wet feet. When the top inch of my soil feels dry to the touch, water me deeply until water flows freely from the drainage hole at the bottom of my pot. This ensures my entire root ball is moistened. Crucially, you must empty the saucer underneath my pot after 15 minutes. I should never sit in standing water. After this deep watering, leave me alone until the top inch of soil dries out again. The frequency will change with the seasons—I need more water when I am actively growing in spring and summer, and much less during my dormant period in late fall and winter.
My ideal light is bright but indirect. A north or east-facing window is perfect. If I am placed in a hot, south-facing window, the intense direct sun will scorch my segments, causing them to turn yellow or a stressed reddish-purple and wilt. Move me to a gentler spot immediately. I also prefer stable, moderate temperatures between 70°F and 80°F (21°C-27°C). I am highly sensitive to drafts, whether hot from a furnace vent or cold from a leaky window. These sudden temperature fluctuations put me under immense stress, which manifests as wilting and bud drop if I am in bloom.
If you have ruled out water and light issues, consider my roots. I actually prefer to be slightly pot-bound, but if I have been in the same soil for many years, it can break down and become compacted or saline from fertilizer salts. This poor soil condition can prevent proper drainage and aeration. If it is time to repot me (best done in spring), choose a pot only one size larger with an excellent drainage hole. Use a specialized potting mix formulated for succulents or cacti, which is fast-draining. Gently loosen my root ball and remove any black, mushy roots before placing me in the fresh, well-draining soil. This gives my roots a new, healthy environment to recover in.
