Question
Hi Mr. King,

I have a Phal that's been living in an east-facing window for about 7 months. It currently has 3 leaves and a spike with 9 blooms that look pretty good (the first 6 are about 6 weeks old, the last 3 are about 2 weeks). The plant is in a well ventilated clay pot with moss (it was repotted about 4 months ago). It receives water once a week.

Recently, the lower 2 leaves started looking wrinkled and less-green. Worrying, I took it out of the pot and saw that most of the roots are in bad shape. They are not what I would call 'mushy' (they aren't slimy, smelly, or gross), rather many are hollow, dry, and brown. Several that are hollow and dry near the base of the plant turn white and firm(er) a couple inches down. The only roots that look good are the couple short aerial roots near the top.

After reading your previous posts, I went today and bought a plastic pot with holes and some orchid bark. I will repot into this tonight. So, here are my questions:

- From the above, does it sound as if my problem is over-watering or under-watering? Either way, does this matter for treatment?

- Should I cut off the roots that are hollow and brown toward the top, but still white / firm at the ends? (If I do, this won't leave the plant with much).

- After repotting as you recommend (bark, soaking and draining, etc.), do you feel that other steps such as bagging or misting will significantly help the plant's recovery?

- I have read several threads before finding yours where folks have suggested that using a root growing hormone can be helpful? What do you recommend?

Thank you very much for your help and for taking your time and sharing your knowledge with the rest of us.

Sincerely,

-morgan

Answer
Morgan, thank you for doing your homework and entrusting your remaining questions to me.

The question of whether you overwatered is difficult to answer because a lot depends upon the type and status of the potting mix. Moss is a particular tricky potting mix for orchids because it tends to absorb a lot of water, but not necessarily uniformly- unless it gets thoroughly soaked. Usually, the last part of the moss to dry is in the bottom of the pot, which means the roots stay wet too long.  Another problem with moss, is that it tends to compact, interfering with drainage and the flow of air through the mix.

Orchid roots consist of a central thread (which is the conducting unit) and a surrounding spongy layer of cells called the velamin.  The velamin stores water and nutrients which it releases through the conducting central thread to the vegetative parts of the plants.  The velamin also contains chlorophyl so can use light to photosynthesize. Both root elements are necessary for a healthy plant.  However, it is possible that some parts of the velamin may be destroyed while other parts remain intact.  As long as the central thread remains intact it can still conduct water, minerals, etc from intact parts of the velamin.  Therefore, I would not remove any part of the root which has lost some velamin as the remaining velamin can continue to function. When repotting, You should try to get the aerial roots into the potting mix. Be sure to soak them heavily before attempting this.  The soaking will make the roots less brittle and less prone to damage when you attempt to insert them into the potting mix.

The rooting hormones that I am familiar with (eg rootone) are a combination of rooting hormones and fungicide. I think the plant might benefit from the combination.

Just a caution on the repotting (you may have read this already): dry fir bark needs to be well soaked prior to use.  It tends to repel wetting and can take water away from the roots if dry.