What Are the Causes of Spike Death in Orchids?

Root Rots

• There are a number of fungal diseases that can attack an orchid if the moisture level in the soil has risen too much to fend them off. Roots rot when the soil becomes overly saturated with water and oxygen cannot reach the roots. The roots die and in many fungal infections that cause root rot, the fungus then moves up the rest of the plant or attacks the foliage. The worst thing about fungal infections is that their spores travel easily to other plants.

Proper Watering

• Only water orchids when the top of the potting media is dry to the touch and dry below the soil surface. Place the pot in the sink and water it until water comes out the drainage holes. Watering the plant in the sink will prevent the water from gathering in a tray beneath the plant, which is not healthy for orchids and invites rot. The type of water you use may also have an impact on spike health, as water high in soluble salts will harm the plant as the salts accumulate in the soil. Usually, tap water is perfectly suitable for orchids, but if you know yours is treated or otherwise high in soluble salts, consider watering with filtered water.

Potting Media

• There are many types of potting media suitable for orchid culture, and it's difficult to recommend one particular medium or combination of media that is best for orchid health, but whichever you choose, remember that the primary function of the potting media for most orchids is to support the plant--literally to hold it upright. It should be very well draining and shouldn't retain too much water.

The Wrong Pot

• The size and type of pot will also control how much water an orchid gets and its chances of suffering from root rots. Clay and terra cotta pots absorb water and pull it out of the soil. They often require the grower to water more frequently, but the chance of fungal infection from water retention is also diminished. Plastic pots maintain soil moisture for longer. If the pot is too big for the orchid, the plant will require more water to soak the soil, which means more water will hang around in the soil for a longer period of time.