Question
QUESTION: Hi,

I have a phal that I originally received as a gift. When I first got it I didn't know a thing about caring for orchids. I  left it at my office and watered it with a thorough soaking about once every 3-4 days. It was sitting by a window, but the glass was tinted so who knows what kind of light it was really getting.

I took it home and put it on my back porch, although it was shaded by the overhang and sides of the balcony and had a northern exposure. We had a very hot summer last year (15 days above 100, I think it was) and I don't think I kept it watered enough, as the leaves began to yellow and shrivel. I repotted it in a rather large clay pot with a drainage hole on the bottom, but none on the sides. I also placed seashells in the bottom of the pot to assist with drainage, along with a few styrofoam nerdles. The plant started to perk up a little after repotting (this was early fall, by the way) and started growing a new leaf about a half inch to the side of the original leaf and crown structure. It was like it was growing an entirely new plant! Eventually (about 6-8 months later and a week ago) the entire old plant had died off and been replaced by a new plant, now with 4 leaves, just beside it. I think the old plant's roots are still providing nutrients for the new plant, but I'm not sure....Okay, lots of backstory, but now to my question:

First off, I now grow this outdoors in a very wooded environment, similar to what I understand to be a phal's requirements (filtered light, etc.). But I've noticed a presence of larva and actual flies in the potting mix, and especially  if I move the top inch or two out of the way and really look down in there...Should I be concerned about this? Or is it natural due to the break down of the bark and mainly organic potting mixture I have? Should I repot in an inorganic mix? If so, when should I do this? Also the "old plant's" base is still present, although I can't tell if it's alive, or going to grow anything, or what...Should I do anything to it?

The "new" plant is showing the signs of either 2 new roots extending from its base, or perhaps a spike or two. I've never seen a spike as it starts so I can't tell the difference. But they're both "jewel-tipped" deep reddish purple, so I'm guessing roots. Should I just let it be until the fall and see if it spikes?

ANSWER: Thanks for the detail Chris.  Normally, one of the functions of repotting is to wash the roots and check to see if any have rotted or are starting.  I assume, because you didn't comment on this, that all roots were firm and healthy. The presence of insects in the potting mix suggests to me that the mix has broken down too much. I prefer a combination of organic/inorganic potting mix.  You will find this is the case with most commercial orchid potting mixes.  The principal organic component is fir bark and/or tree fern.  The inorganic components are perlite and charcoal although some also use expanded clay as a component.  The advantage of this type of mix is to provide more air movement at the roots.  The mix of organic and inorganic components provides a safeguard to the organic component.  When it begins to break down, restricting air flow at the roots, the inorganic component helps keep the potting mix "Open" until repotting can occur.

I think you should repot the plant in the type of mix described above and plan to do an annual repotting after flowering. After unpotting, wash the roots and remove any that are mushy or don't look healthy before repotting. If you have an east facing indoor window, I would recommend you bring the plant in and place it there. I don't recommend growing phals outside where they can be stressed by environmental extremes. They prefer 60-85 degrees.  The other option is to summer it out only when the temperature range does not exceed this and on days when it does, bring the plant indoors.  Try to keep the pot well above ground level or you are likely to attract snails and slugs and other critters.

Most phals flower in the spring so I agree that you are having the development of aerial roots.  When you repot, see if you can incorporate those into the potting mix.  Be careful as they tend to be very brittle.

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QUESTION: Sorry, I left that part out. I'd say that about 85-90% of the roots were healthy, so I pruned the ones that were not. I then did wash the roots off before repotting.

I used some common orchid potting mix that I picked up at Home Depot which did contain some inorganic components--I think some large coarse perlite and maybe some charcoal. I also added some sphagnum moss into the mix (maybe 20%) to help retain water as I felt at the time that it was drying out too quickly.

Now, I do have a sunroom with an eastern exposure, but it is actually pretty shaded by trees so it really doesn't get a whole lot of sun. Maybe just a little "filtered-through-the-tree-leaves direct sun" in the morning...do you think this would be sufficient?

Also, since it hasn't flowered yet, do you think it won't until perhaps the fall? Or next spring even?

Answer
The Home Depot orchid potting mix is fine.  I usually soak it overnight before using it because fir bark, in its dry state, repels water.  Adding sphagnum can be tricky.  Long fibred sphagnum is preferred.  Your sunroom should be fine.  I think your plant will likely flower next spring-- its normal flowering season.