Campbell Orchid Fertiliser A (Yellow) is a water-soluble orchid fertiliser formulated for the flowering stage of the orchid growth cycle. With an NPK analysis of 11.8-13.2-16.6 plus trace elements, its relatively higher phosphorus and potassium levels and lower nitrogen content are designed to support flower formation and flowering.
The yellow crystalline powder dissolves in water for easy application and supplies nitrogen, phosphorus, potassium and essential trace elements in a formulation developed specifically for orchids.
When to Use Campbell Orchid Fertiliser A
Orchid Fertiliser A is intended for use from the initiation of flower spike formation through to the end of flowering.
In temperate areas of Australia, Campbell recommends applying Orchid A from approximately January through to the end of August. In warmer tropical or cooler southern climates, the application period should be adjusted to match the actual flowering and development cycle of the orchids rather than relying solely on calendar dates.
After flowering has finished, change to Campbell Orchid Fertiliser B, the higher-nitrogen formulation designed for the vegetative growth phase before the next flower spike develops.
Why Use Orchid Fertiliser A?
- Formulated specifically for the flowering stage of orchids
- Supports flower formation and flowering
- Higher phosphorus and potassium with lower nitrogen than Orchid B
- Water-soluble crystalline formulation
- Contains nitrogen, phosphorus and potassium plus mineral trace elements
- Suitable for periodic or constant feeding programs
How to Use Campbell Orchid Fertiliser A
Periodic Feeding
Mix 20 g of Orchid Fertiliser A with 7 litres of water and apply as a normal watering every 7–14 days, or as plant or growing-media requirements indicate.
Campbell identifies 20 g as approximately one supplied measuring spoon.
Constant Feeding
For growers using a constant-feeding system, Orchid A may be applied each time the orchids are watered. Campbell recommends a nitrogen concentration of approximately 50–75 ppm when using this method.
For proportioner systems, Campbell provides the following guide for preparing 20 litres of concentrate:
| Proportioner Dilution Ratio | Orchid A per 20 L Concentrate – 50 ppm N | Orchid A per 20 L Concentrate – 75 ppm N |
|---|---|---|
| 1 to 5 | 40 g | 60 g |
| 1 to 10 | 85 g | 130 g |
| 1 to 15 | 130 g | 190 g |
| 1 to 20 | 170 g | 250 g |
NPK & Nutrient Analysis
Campbell Orchid Fertiliser A has an exact analysis of 11.8-13.2-16.6 plus trace elements. Campbell also commonly describes the formulation in rounded form as NPK 11:13:16 + trace elements.
- Total Nitrogen (N): 11.8%
- Nitrogen as nitrate: 5.9%
- Nitrogen as ammonium: 5.9%
- Water-soluble Phosphorus (P): 13.2%
- Potassium (K): 16.6%
- Zinc (Zn): 0.01%
- Copper (Cu): 0.01%
- Cobalt (Co): 0.002%
- Molybdenum (Mo): 0.01%
- Iron (Fe): 0.03%
- Boron (B): 0.006%
- Manganese (Mn): 0.05%
The balance of relatively higher phosphorus and potassium and lower nitrogen is designed for the flowering phase, helping to promote flower formation rather than the stronger vegetative growth encouraged by Orchid B.
Orchid Fertiliser A vs Orchid Fertiliser B
Campbell's two-part orchid feeding program uses different fertilisers for different stages of orchid development:
- Orchid Fertiliser A (Yellow) – for use from flower spike initiation through to the end of flowering.
- Orchid Fertiliser B (Blue) – the higher-nitrogen formulation for vegetative growth after flowering and before the next flower spike forms.
Using the appropriate formulation for each stage allows the nutrient balance to better match the orchid's changing requirements throughout its flowering and growth cycle.
Compatibility
According to Campbell Chemicals, Orchid Fertiliser A is compatible with most pesticides and with copper oxychloride. It should not be mixed with Bordeaux mixture, copper sulphate or lime sulphur. Campbell also advises against mixing Orchid A with emulsifiable concentrate pesticide formulations.
Available Sizes
Available in 500 g, 3 kg and 10 kg sizes. Campbell's product information specifies that the 500 g pack includes a measuring spoon.
Disclaimer: Always read and follow the instructions on the product packaging before use, and don't depend on information on this page that may have errors or be outdated.