Question
QUESTION: Hi there,
I bought an orchid (not sure what type. It's a larger plant with white petals which bleed into pinky/purple in the middle with purple centre) a year ago and it has been very healthy and is currently loosing it's flowers for the second time.  I inspect it regularly for changes and have notice that the new leaf that is coming in has a bit of white.  At a closer look, half of the base has turned white with leaves on one side having turned white as well at the base.  Leaves on the other side of the base are fine.  This has happened quickly as it was not like this a week ago.  The only thing I can think I might have done is I put an airborn root into the soil and it made a bit of a crunch sounds as I did it (regretted doing this afterwards!).  Would that be the cause or does it need more nutrients/fertilizer of some sort?  Thank you for your time.

ANSWER: Diana, I don't think the condition you describe would have occurred by damaging an airborn root.  My first thought is that it may be an insect infestation.  The easiest way to check this is to use a q-tip soaked in alcohol and rub the white area. If this removes the white and exposes the leaf, you most likely have an infestation of mealy bug which is a cottony white and likes to congregate in large numbers un the undersides of leaves.  If this test reveals the presence of a pest, switch to cotton sabs soaked weith alcohol and wipe all infested areas.  Recognize that this is just an initial treatment.  There will be insect eggs and insects also down in the potting mix so after the initial treatment you will need to unpot the plant and soak it in an insecticide before repotting.  Use Bayer Advanced formula or another effective against mealy.  Once you have drenched the plant (be sure to wear rubber gloves), let it dry and repot it in a new pot in fresh orchid potting mix.  Be sure the new orchid potting mix is damp prior to use.  This might seem like overkill, but mealy bugs are every orchid grower's nightmare so it's wise to be thorough.

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QUESTION: Hi Wayne,
I did the alcohol test and nothing came off, so no bugs! From the look of the leaves, it seems to be more of a apart of the leaves than on top of them.  Like the leaves are turning a little yellowish then white, although it has regained some colour over the past few days.  We had a real sharp change in weather (hot to cold chill), could this be it?  I also bought some orchid food to try and see if this will help as I've only given it water in the last year and no fertilizer or food.  I would appreciate any further thoughts you may have.
Thanks.
Diana

Answer
Diana, glad the test came out negative.  New growth can be affected more by sharp changes than older growth so that could have a bearing. If the plant, or part of it, was exposed to very bright light light even for a short time, the whitening that you see could mean the chlorophyll was bleached out of the leaves causing the whitish appearance.  Temperatures over 90 degress could also adversely affect leaf color.  Phalaenopsis are basically house plants and prefer temperatures of 65-80 degrees and morning sunlight in an east window.

If you haven't repotted the plant, this would be a good time.  It will enable you to determine the root conditions.  Purchase some orchid potting mix and soak a portion to be used to repot your plant.  Then, unpot your plant and rinse off the roots.  They should be firm and, when wet, should be a green color.  Any mushy or collapsed roots should be removed.  Many orchid problems result from root rot, so it is good idea to annually repot your plant just after flowering.  Use a plastic pot with lots of drainage holes in the bottom and/or sides.  If you have mostly healthy roots, you may need to repot to a slightly larger pot (an inch to 2 inches in diameter larger).  If you have some rotted roots, after removal the root mass may be small enough to get them back into the same pot.  Carefully place the rinsed roots into the pot (sometimes the roots go in better by holding the plant and slowly rotating the pot as you  lower the root mass into the pot.  Slowly place the wet fresh potting mix into the pot and tap the pot from time to time to help settle the mix around the roots.  Do this in an area where the excess water can drain away. If you want to put the aerial roots into the potting mix, be sure they are soaked until they tuen green.  They are less brittle then.  Annual repotting is the best way to place aerial roots into the potting mix.  Aerial roots are a natural condition of the plant as, in nature, these plants tend to grow in trees with their roots exposed.  For now, grow the plant in a lower light condition until the new growth looks more healthy.  It is possible that some of the whitish part of the plant may turn yellow and, eventually, fall off. This would occur only if that part has been irreparably damaged by excessive heat or light.  For now, you want to create the right environment for healthy new growth which may take a couple of months.