A relatively simple tip but every time I neglected to follow it, I always regretted it!
Every plant you bring into your collection as a mature plant, no matter whether it is from a major commercial grower or a friend from the street nearby, NEVER just put the plant(s) directly into your collection. Always isolate and pre-treat.
In the good old days I would drench with Dimethoate but that option is now unavailable. Today I isolate and either heavily spray over the plant or cover the medium and immerse the above media parts of the plant into a bucket of diluted paraffinic oil.
The other precaution I recommend is to put in a bright plant tag (yellow is good) to remind you to repot any new introductions into your standard medium as soon as possible. Plants in mixed media formulations are impossible to grow well overall. We only use Orchiata bark and vary the proportions of particle sizes according to the size of the pot into which we are potting.
This is a “do as I do”, not a “do as I say”!
Pierre Pujol, Grower / Breeder of Cymbidiums
“Let your roots breathe”
Most orchids are epiphytes, which means their roots need to breathe. Many of us come to orchids from growing terrestrial plants and, as such, we like a denser soil than what is often required for orchids. Why is this important?
When the media in plastic pots becomes water-logged, especially in colder weather or when the media starts to break down, the orchid roots cannot breathe anymore, and they die. Rotting organic materials often attract undesirable organisms, such as fungus and anaerobic bacteria which accelerate media degradation and plant infections.
Do I have this problem?
Dead pseudobulbs and dying leaves towards the center of the pots are sure giveaways to this problem. These plants are not growing as well as they should, because their roots are unable to absorb nutrients and exchanges gasses.
The Solution to the problem:
Do not overpot (Editor: common advice is to repot in a pot that can handle two years of growth); use pots with plenty of aeration holes you can even drill holes if the pot isn’t open enough. Select a media mix that provides enough aeration inside the pot (such as porous inorganic materials). Check roots once a year by taking plants out of pot and change soil media when you start seeing root rot or that your media is breaking down.
Paul Chim reminded us how orchids grow in the wild, usually as epiphytes, an amazing adaptation. The average seedpod is approximately the size of a small pickling cucumber and contains millions of tiny seeds. The seeds are easily dispersed and may become embedded in other plants such as trees. There are no nutrients in the seeds which, for germination in their natural setting, rely on help from beneficial organisms such as specific fungi which provide sugar and other required nutrients through organic breakdown and which can remain associated with the plant throughout its lifetime. Seeds germinated in the laboratory do not require fungi as a nutrient medium provides the components required for growth. Wanting to mimic Mother Nature, Paul continues to test modifications to his already solid growing program.
He shared the steps he follows to grow exquisite orchids, many of which have been AOS prize winners. The steps and the processes he outlined as important for growing great orchids were simple and easy to understand: potting, light, roots, nutrients, and pests.
Potting / Repotting. His routine for potting / repotting plants used economical products as much as possible. He suggested soaking the plant in fresh 3% hydrogen peroxide as a way to kill microorganisms, especially viruses and fungi. He also uses Lysol wraps to clean his hands and the plant while he is working again to minimize contamination. He also will let a plant sit out for up to a week or so before placing it in the medium.
Paul reminded us to look at the roots. If you don’t know what to look for, experts can provide advice on what healthy roots look like. Paul likes Tarantula brand liquid bacterial solution as a probiotic for the roots. After repotting, Paul uses Superthrive, available at hardware stores and nurseries.
Light. This is a topic of its own, but pay attention to what you read from trusted orchid growers and reference materials. Proper quality light is essential to growing a beautiful plant.
Medium. Long a fan of coconut coir, Paul no longer uses it because it can have a high salt content or can become too acidic. He has switched to 100% bark, specifically Kellogg fir bark which is available from Alan Koch at $10 for 2 cu. ft. If your plant requires moss, there are problems with most moss available. Paul recommends only the long-fibered sphagnum moss (New Zealand) which is harder to find and expensive but very well worth it.
Nutrients. Paul uses a variety of supplements to grow his orchids. For slow release, he uses Nutricote 13-13-13. It needs to be replenished every six months but, unlike Osmocote, it is slow release even at higher temperatures. Fish emulsion is another well regarded nutrient source and is inexpensive. Chelated Iron and Zinc promotes flowering and is easy to find at most garden centers. He also works Metalosate Calcium, a foliar supplement, into his nutrition program.
Protection from pests: Paul finds that horticultural oil works well; he uses 25 tablespoons per gallon in his sprayer and said this results in a milky appearing solution.