Growing Orchids from Flask
De-flasking is a little bit of a tricky process but very rewarding when you see your little plants growing. The optimum time for de-flasking is spring when the weather is starting to warm up and the ‘spring-growth’ period begins. Have a look at your fruit trees and see when they begin flowering and growing their leaves. The last preferred deflasking time would be late summer to early autumn so that there is enough time for them to ‘harden-off’ before the chills set in.
Once you receive your flasks, leave them sit for a couple of weeks in a position where they will receive high light but no direct sunlight. A south facing windowsill or in a protected greenhouse are two suitable places. The reason for this is to get the plants to start photosynthesising. You will start to see a lot of condensation forming on the inside of the jar. Having been photosynthesising the plants, once potted, will already have a head start in growing and feeding on their own rather than off the sugar contained in the agar. A day or two before you are ready to de-flask your plants, unscrew the lid and leave it sitting loosely on top of the jar. This will start acclimatising the plants to their new home.
Getting started, mix up a bowl of lukewarm water and fungicide (following packet directions). Gently remove the plants from the flask trying not to damage the roots. Wash the plants in the fungicide solution rinsing off all remnants of the agar from the roots and carefully separating the plants. Drain the plants and leave to dry off on some newspaper or paper towels for about 15-30 minutes. Plant them altogether into a pot that is about halve as big again as the flask they came out of. You want to have about 1cm spacing between plants. Use either rehydrated long-strand sphagnum moss or number 2 (5-10mm) orchid bark that has been soaked overnight. Place a plant label into the pot writing the name of the plant on one side and the de-flasking date on the other. An HB pencil is recommended for this as it is waterproof and doesn’t fade.
Place the pot back into the greenhouse in a protected corner where it will receive good light but no direct sunlight as well as good air movement but not cold. If you choose to de-flask before winter the plants will need protection from the cold. Don’t let the temperature get below about 5oC overnight. Once planted, you may like to place the pot inside a larger sized zip-lock plastic bag. Seal the bag leaving approximately 2-3cm unzipped. This helps to create a microenvironment for the baby plants. The alternative would be to grow them indoors over the winter. You can still use the plastic bag to create the microenvironment indoors.
The plants will need to stay in this initial pot for about 3-6 months. Water them about once or twice a week alternately feeding them with a weak solution of high nitrogen fertilizer such as Growing Orchid Tucker. You want to let the mix (bark or moss) be evenly damp without total saturation. The frequency of watering will fluctuate depending upon the temperature and rate of evaporation. Ensure that there is no water sitting around the bottom of the pot as the roots need to be able to breathe. Spray the plants with a fungicide solution if you see any brown leaf tips or spots on the leaves.
Once the plants have grown to approximately double their size they can be planted out into individual pots. We use 5-7cm square pots for smaller plants and 10cm square or round pots for larger plants. At this stage plant them into either a number 2 or number 3 bark. Keep up the same watering and feeding regime but increase the fertilizer to full strength. Also maintain the fungicide regime as and when needed. After a month or so, provided the weather is not too cold, move the plants into their final growing environment depending upon the needs of the type of orchid. Each new pot will require a label containing the plant’s name and the date of potting on the reverse.
Remember, rain acts as watering for outdoor plants. If you have heavy rainfall, ease back on the watering. If you have high temperatures and high evaporation, increase the frequency of watering. Likewise, cool temperatures means less watering. Keep an eye on the plants and pot them up into the next size pot when they start to outgrow their current one. Add the new potting date to the reverse side of the label. You can then easily monitor when you last potted that plant. You should have a near flowering sized or flowering sized plant in a 15cm diameter pot in approximately 2 ½ - 4 years depending upon the type of orchid. At this stage start using Flowering Orchid Tucker as per directions to help flower initiation.