Orchids, particularly the common Phalaenopsis (Moth Orchid), are popular houseplants known for their striking, long-lasting blooms. Watering is often the most confusing aspect of their care. A common question is whether these plants require more hydration when actively flowering. The answer involves understanding the orchid’s unique biology and metabolic demands during the blooming stage.
Understanding Baseline Orchid Hydration Needs
Most common orchids are epiphytes, meaning they naturally grow attached to trees or rocks, not in dense soil. This lifestyle dictates a unique watering requirement: a cycle of thorough wetting followed by near-complete drying. The thick, spongy outer layer of the roots, called the velamen, rapidly absorbs large amounts of water and nutrients before the air dries them out.
The potting medium, usually a mix of bark, sphagnum moss, or charcoal, anchors the plant and maintains air circulation. Because bark dries out faster than moss, the type of medium significantly influences watering frequency. For a Phalaenopsis in a standard bark mix, the baseline frequency is every seven to ten days, allowing the roots to dry fully. This wetting-and-drying rhythm is fundamental to preventing root rot.
Watering Adjustments During the Blooming Cycle
Yes, orchids generally require a slightly increased frequency of water when they are in bloom. The production and maintenance of a large flower spike is a metabolically expensive process. Flower petals lose water through transpiration, creating an additional surface area from which moisture evaporates.
This increased water loss, coupled with the need for hydration to keep the flowers turgid, means the potting medium dries out faster than usual. You may need to water one or two days sooner, perhaps every five to seven days instead of every seven to ten. The core principle remains the same: always allow the potting medium to approach dryness before rehydrating it completely.
When watering a blooming orchid, avoid splashing water onto the flowers or into the crown (the central growth point between the leaves). Water trapped in the crown can lead to crown rot, a potentially fatal fungal infection. Ensure the water drains completely from the bottom of the pot. Water early in the day so any accidental moisture on the foliage or blooms has time to evaporate.
Practical Methods for Assessing Moisture
Relying on a fixed calendar schedule is unreliable, as factors like temperature, humidity, and airflow constantly change the rate of evaporation. A better approach is to physically assess the moisture level of the potting material. The easiest indicator is the color of the orchid’s roots, especially when the plant is grown in a clear plastic pot.
Healthy, dry orchid roots appear silvery or grayish-white because the velamen is filled with air. Once thoroughly watered, these roots change color to a vibrant green as the velamen absorbs water. Wait until the roots have returned to the silvery-white stage before watering again, even during bloom.
For orchids potted in opaque containers or dense moss, the “skewer method” provides a reliable internal reading. Insert a clean wooden skewer into the medium near the center of the pot and leave it for a few minutes. If the skewer feels damp, looks darker, or has wet mix clinging to it when pulled out, the plant does not need water. Lifting the pot is a simpler, though less precise, method; a dry pot feels significantly lighter than a freshly watered one.
Post-Bloom Care: Returning to the Vegetative Cycle
Once the last flower has dropped, the plant completes its reproductive cycle, and the need for increased water declines immediately. Revert to the baseline watering schedule established before the flowering spike emerged. This means extending the time between waterings, allowing the medium to dry out more completely as the plant’s metabolic activity slows.
The spent flower spike requires attention, particularly for Phalaenopsis orchids. If the spike turns completely brown or yellow, trim it away near the base of the plant. If the spike remains green, you may cut it back just above a node (a small bump on the stem) to encourage a potential rebloom, though resulting flowers are often smaller. The primary focus is returning the orchid to its resting, vegetative state to conserve energy for the next growth cycle.