Growing an orchid in water, often called semi-water culture or full water culture, is an alternative to traditional potting. This method is popular for its simplicity and the ease with which root health can be monitored. It eliminates the risk of media breakdown, a common cause of root rot in traditional bark or moss mixes. This approach aims to mimic the natural, humid, and well-aerated environment of epiphytic orchids in the wild.
Transitioning the Orchid to a Water Environment
The transition begins with selecting a suitable plant, with the Phalaenopsis (moth orchid) being the most commonly recommended choice due to its robust nature. First, remove the orchid from its existing pot and carefully strip away all traces of the old potting media, such as bark, moss, or foam. Soaking the roots briefly can help loosen tightly packed moss, making the removal process gentler and more thorough.
After all media is removed, the roots must be cleaned and inspected for any signs of decay. Healthy roots are typically firm and plump, often appearing green when wet or silvery-white when dry. Conversely, dead or rotting roots will feel mushy, soft, or hollow, and appear brown or black. Trim away all diseased or damaged sections using sterilized scissors or shears to prevent the spread of pathogens.
The remaining healthy roots should be allowed to air-dry for several hours, or even overnight, before being placed into the water container. This drying time allows any minor cuts or abrasions on the roots to heal and callus, which minimizes the entry points for bacteria and fungus. New roots that grow after the transition will be better adapted to the water culture environment, so preserving healthy original roots is important for the plant’s initial stability.
Requirements for the Water Reservoir and Environment
The physical setup requires a clean container; a clear glass jar or vase is preferred because it allows for easy monitoring of root health and water levels. The container should be large enough to support the orchid and allow the roots to hang without being overly crowded. The primary focus is ensuring that the roots have access to both water and air, which is fundamental to the health of an epiphytic orchid.
The water used should be free of high mineral content and chlorine, as these can accumulate and damage the sensitive roots. Rainwater or distilled water are ideal choices. Filtered tap water that has been allowed to sit out for 24 hours to allow chlorine to dissipate can also be used. The water should be room temperature to avoid shocking the plant’s root system.
A fundamental aspect of water culture is the submergence level of the roots. Only the bottom one-quarter to one-third of the root mass should be submerged in the water reservoir. This arrangement leaves the majority of the roots exposed to the air, satisfying the orchid’s need for oxygen exchange. The reservoir should also be placed in an area that provides bright, indirect light, avoiding direct, intense sunlight that can overheat the water and roots.
Fertilization and Ongoing Care in Water Culture
Since water lacks the necessary nutrients for sustained growth and flowering, a regular fertilization schedule is required. The general rule is to feed the orchid “weekly, weakly,” meaning a highly diluted solution is applied frequently. Use an orchid-specific fertilizer at an extremely dilute strength, typically between 1/4 and 1/8 of the manufacturer’s recommended dosage.
Fertilizer should be mixed into the water used for the weekly water change, ensuring the plant receives a steady, low dose of nutrients. Weekly or bi-weekly water changes are necessary to prevent the buildup of fertilizer salts and minerals in the reservoir, which can lead to root burn. When changing the water, flush the roots thoroughly with plain, clean water to wash away any accumulated residue before the fresh, fertilized water is added.
During the water change, the roots should be closely monitored for any signs of distress or decay, such as mushiness or discoloration. The old roots may initially struggle, but the appearance of new, healthy, green-tipped roots is a positive sign that the plant is adapting. Mild algae growth is common inside clear containers and does not harm the orchid, but the reservoir can be scrubbed periodically if the appearance is undesirable.