Successfully sowing orchid seeds requires the hobby gardener to rethink things. In order for an orchid to produce a seed capsule at all, it must be pollinated manually. The seeds inside do not have nutrient tissue like other plant seeds, but are dependent on a symbiotic fungus. Therefore, a special in vitro method was developed to ensure that the seeds still germinate, using a nutrient medium that replaces the mycorrhizal fungus. We will explain to you here exactly how the procedure works.
How do I sow orchid seeds successfully?
To sow orchid seeds successfully, you need an in vitro method, as orchid seeds have a symbiotic fungus and no nutrient content. Sterilize the seeds, place them on an artificial growing medium and provide warm, bright conditions without direct sunlight.
Material list
The following equipment and supplies are kept handy near a kitchen stove:
- cooking pot
- Spirit burner
- Grid
- Small screw jars
- Test tubes with ready culture medium
- Tweezers
- vaccination loop
- Stapler
- Sharp knife or scalpel
- Gloves
- Coffee filter
- Cotton pads
- Distilled water
- Ethanol (70 percent)
- Hydrogen peroxide (3 percent)
Hydrogen peroxide is used for disinfection and is available in a ready-to-use 3 percent dilution in pharmacies and online shops. You can read here how to easily prepare nutrient medium.
Obtaining and preparing seeds from a seed capsule - this is how you do it right
If manual pollination was successful, wait until a seed capsule pops open. Cut these off, shake the seeds onto coffee filter paper and form them into an envelope, sealed with staple pins. The seeds must be sterilized before sowing on the nutrient medium. This is how it works:
- Pour the water into the saucepan to a depth of 3 cm and bring to the boil
- Clean the wire rack with ethanol and place it on the cooking pot
- Fill a screw-top jar about 1 cm high with hydrogen peroxide
Using tweezers, place a seed envelope in the solution for 10 minutes. Repeated tossing ensures that all seeds are moistened.
Apply seeds to the growing medium
The following work is all carried out over a constant stream of steam that simulates the conditions of a sterile workbench. Follow these steps:
- Place a cotton pad soaked in ethanol and a glass of distilled water on the wire rack
- In the stream of steam, use tweezers to remove the seed envelope from the glass and place it in the distilled water
- Swirl the seed envelope in the water and place it on the cotton pad to open it with the tweezers and scalpel
- Take a test tube with culture medium, open it in a stream of steam and place it on a cloth soaked in ethanol
Using the inoculation loop, you can apply the seeds from the envelope directly to the nutrient medium and distribute them there. Then close the test tube again with the plug and put on an aluminum foil cap, ideally closed with a rubber ring. It is important to note that you clean the tool with ethanol before and after each work step or burn it briefly over the alcohol burner.
Tip
After sowing, place the culture vessels in a warm location at 25 degrees Celsius in a bright location without direct sun. There should be no strong temperature fluctuations here that could trigger a change in pressure in the test tubes.
