Tips for Orchid Growing

These are the tips that OSRBG members provided to each other at the meeting on May 24, 2015.

Native orchids: where to obtain, how to grow

• There is often a native plant sale in north Toronto at this time of year (not just orchids).
•  Do not harvest plants in the wild (illegal).
• Be wary of moving plants even on your own property as transplanting time is very specific depending on the orchid species. Success can be elusive as the plants often have very extensive roots systems that radiate outwards only a few cms below the surface.  Pre-established plants from a reputable nursery grown from seed are a much better bet.
• Conditions required are also demanding. Drainage is critical. Some have a symbiotic relationship with certain fungi. In general, they do not like to be too close to bushes and trees as the roots need room to expand horizontally. They tend not to be deep feeders.
• If you have one in a fibre pot, you could try burying the pot.

Cymbidiums: when to move outside and where to put them; do you have to put them outside in order to get bloom spikes?

For large standard Cymbidiums but not the ‘warm growing’ Cymbidiums such as the species Cym. findlaysonianum.

• They can go out as soon as the risk of frost is over and stay out almost until the first frost. They need a cool period in order to encourage blooming.
• They like dappled light. A lath house is good.
• You can heel the pot into the soil (bury the pot up so that soil level inside is level with levels outside) to prevent the pot from heating up too much (always a risk, especially with black plastic pots). Insects may be a problem, but this is always an issue when you move plants outside and then back into the house.

For Chinese Cymbidiums (grown mostly for their foliage) and some mini-cymbidiums (so-called)

• They don’t have to be moved outside and also tend to be smaller so they require less space when grown inside. If you choose to put them outside wait until temps are warm and return before temps cool in the Fall.
• They prefer less light than the larger varieties to encourage variegation in their leaves
• Putting plants outside can be a risk because of squirrels digging in the pots to hide nuts, nibbling on the plants or unpotting the plants for you; even birds have been known to do some damage (woodpeckers removing tags!).

For the ‘warm’ growing larger Cym’s such as Cym findlaysonianum

• IF one chooses to put these outside, wait until the outside temps are warm enough but be exceedingly careful in transport as well as in pot placement as the flower spikes will be developing over the sides of the pot and will hang down as much as a meter when mature in some varieties.

Fertilizers

• Recommendation received not to fertilize cymbidiums and nobile-type dendrobiums after mid-summer (stop in July). Otherwise use 0-10-10.
• Slow release fertilizer is good to use when putting plants outside, so you can water without worrying about fertilizing.
• You can also use slow release fertilizer indoors (e.g. Miracle Gro 20-20-20) if you can’t keep to a regular schedule during a particularly busy time.
• There is a video on this topic in which Dynamite is recommended; Osmocote is not recommended as it can release too quickly. https://www.youtube.com/watch?v=SaRfPOZv5R0

Lighting

• If you grow under lights, you should have a light meter. They are not expensive when you consider the outlay you have already made for the lights and plants, and it is important to know exactly how much light your plants are getting.
• Monitoring the light will also answer the question as to whether bulbs need to be replaced (i.e. you can tell if the amount of light is diminishing over time).
• There is a new gadget called Light Scout DLI 100 (about $50 or so) that gives you a reading at the press of a button, or you can run it for 24 hours to get a report on the amount of light over time (measures DLI – Daily light intensity).
• If growing under lights in the basement, you can run the lights at night when the electricity is cheaper instead of during the day; the plants don’t know the difference!
• You can also place your plants so the ones that need a lot of light are directly under the tubes and the ones that need less are a bit either side of the tubes.
• The general consensus seemed to be that most members who grow under lights give the plants the same number of hours of lighting, winter and summer.

Transporting plants during inclement weather

• A coat hanger hoop attached at the corners of a cardboard box will allow you to cover the box with plastic or a lightweight fabric to protect a taller plant without squashing the blooms.

• The sort of plastic “box” with a zipper closer that you might get when you purchase a duvet can also be used around a box to extend the sides upward (see photo)
• Be careful not to have the plant actually touching the plastic in cold weather.
• If you breathe into the plastic bag a few times to inflate it with warm air, it will also help to keep a plant warm while you transport it quickly from the house to your car.
• Assuming your car is already warm inside, you can risk a quick, short trip from house to car even in winter (according to Joe DiCiommo).

“Bud blast”- Why buds may fall off before opening

• Moving from a place they like to a new location, especially if a change in temperature or a cool draft is involved.
• Ethylene gas – produced by ripening fruit. Keep a good distance between the orchids in your kitchen window and the fruit bowl on the counter.

Keikis – Should you cut them off or leave them? (Note: A keiki will be genetically identical to the ‘mother’ plant and bears the name.)

• Your choice: one Toronto grower is famous for growing Phals like “apartment buildings” with keikis growing out of keikis…but they all need to be supported somehow.
• Basal keikis on Phals are VERY difficult to separate successfully from the mother plant and it is better to leave them. Other genera may be more forgiving.
• Keikis on Dendrobiums can also be a problem; the air roots are different from the other roots and may not grow well if you try to start a new plant.
• Aerial keikis (attached to the flower stem) on Phals are more forgiving in this regard. Wait until you have 2-3 inches (cumulative) of roots. Wet the roots by watering or spraying to make them more flexible before removing the keiki and dress the inevitable wound with cinnamon or horticultural sulphur. Can also use physan and water (Physan is used as a cleaner/sterilizer in hospitals and now in greenhouses.)

Multiple spikes on Paphs – how to encourage them

• Patience! Plant has to be mature before it starts producing multiple spikes.
• Once you get a number of growths, the number of spikes will increase exponentially. The message here is to keep the plant whole when re-potting.  Try NOT to separate the growths.
• If you’ve had the plant a long time and it isn’t putting out new growths, try potting it in a different medium.