How to Use Eggshell for Orchids That Have Stopped Flowering

Seeing an orchid stop flowering despite retaining healthy green leaves is a common experience for people who grow these plants. Before turning to chemical fertilisers, many gardeners make use of a straightforward kitchen leftover: eggshell. As it contains calcium and other minerals, it can supplement an orchid’s nutrition when prepared properly. Specialists stress, however, that it should support routine care rather than replace suitable light, correct watering and a balanced fertiliser.

Why can eggshell benefit orchids?

Eggshell consists largely of calcium carbonate, alongside small amounts of magnesium and other minerals. Calcium helps to build cell walls, supports root growth and can contribute to substrate balance. These are all relevant conditions for an orchid to be able to develop new flower spikes.

Flowering nevertheless relies on several factors working together. Most orchids require plenty of bright, indirect light, watering at intervals, a free-draining growing medium and appropriate temperatures. Eggshell alone cannot make a plant bloom if these requirements are not being met.

Watch a video on the Matos Orquídeas YouTube channel explaining when eggshells should be used on your orchid:

How to prepare this natural fertiliser

Preparation is straightforward, although a few precautions are needed to prevent smells and contamination. Use only eggshells that have been thoroughly cleaned and completely dried.

Once ground down, the shells can be used to make mineral-rich water for occasional application while watering.

• Wash the eggshells thoroughly.
• Boil them for around five minutes.
• Allow them to dry completely.
• Grind them into a fine powder.
• Put the powder in a container of water for roughly four hours.
• Strain the mixture, then use the diluted water to water the growing medium once a month.

When to use eggshell on orchids and precautions to take

The most suitable time to use this supplement is after flowering has finished, or when the orchid starts putting out new leaves and roots. At this stage, the plant is actively growing and can make better use of the available nutrients.

Avoid overusing it as well. Frequent applications may lead to a build-up of mineral residue in the growing medium. If whitish deposits, unpleasant odours or signs of mould appear, stop applying it and flush the growing medium using clean water only.

• Use only properly sanitised eggshells.
• Grind them as finely as possible.
• Apply it only once a month.
• Do not replace orchid-specific fertiliser when it is needed.
• Keep the plant in a bright position away from strong direct sunlight.
• Water only when the growing medium is nearly dry.

Is eggshell worth using for orchids?

Used sparingly, eggshell can be a worthwhile addition for supplying orchids with calcium while reusing kitchen waste. It is not, however, a miracle solution. Flowering still depends chiefly on good light levels, suitable humidity, temperature and proper plant care.

The key to a healthy orchid is balance between lighting, watering, ventilation and nutrition. Eggshell can form part of that routine, but it does not replace essential care.