Newbie dealing with rot and maybe gnats

[Naia]

Got a pretty Phalaenopsis from Home Depot almost 3 months ago. It came in a solid ceramic pot with a solid plastic insert without drainage. Transplanted the whole thing to an orchid insert with lots of drainage. Just pulled the whole thing out and popped it in the new insert, no soil change. After the blooms fell and the stem dried out, repotted with Better-Grow Phalan mix and moss about 5 weeks ago. Cleared out the plug and found the center stop (crown?) was all black and icky. Did some root trimming of the brown and black rotted ones and let it dry out for a day before finishing the repotting. It was doing really well after repotting, until this week.

About 3 weeks ago, we started having an issue with these little black gnat-like flies. We've cleaned out the sink/drains, deep-cleaned the kitchen, basically addressed any area with possible food decay. My husband is convinced it's my orchid (or less likely the other plant my daughter has but is always dry because she forgets to water it). We quarantined the plants to a bathroom with a closed door and have seen a few bugs, so it's possible it's a plant.

For the past couple days, the bottom leaf of my orchid started turning yellow at the stump. I moved it to make sure it was getting indirect light, but the bathroom is also kind of cold. Today, the leaf completely fell off. I unpotted it to take a look at what's going on and found more black rot. But, on the plus side, I didn't see any of those flying bugs, larvae or eggs. The pictures are what it looks like right now. I'm letting it dry out unpotted. I also added a picture from when the blooms fell to see how it was potted. I added some moss to the top to keep it from floating when soaking.

I'm at a loss of what to do. I don't want to get rid of the plant, but the bugs are making my husband (all of us) crazy. I want to try and save it from the rot. Any tips or advice or insight are greatly appreciated!

If the answer is "it's a goner", I'd be sad but that's fine. And any suggestion on where and what to get new that will prevent these bugs (if the plant/soil is the reason)

[Roberta]

First, Welcome!

The plant looks OK. The crown is the point where the leaves meet to form a little pocket, in the last 2 photos it looks fine but was that before or after it started dropping leaves? The old mix was the culprit for the bigs., if you have repotted into fresh mix that should help. Just rinse the roots well, and don't cut any more. If the plant can't take up water (due to bad roots or no roots) it will drop leaves to try to save resources.

[Naia]

Thank you for the info!

The 2nd set of pictures (in the pot) are before the bugs and yellow/drop leaves.

The bugs started after I'd repotted in to the Better-Gro Orchid potting mix. It was a new bag, but maybe it was contaminated? Is there a way to save/clean the bag or is it just trash now?

Lastly, would you recommend using a different mix? Or substrate as a whole? I like the idea of lava rocks, but don't know if that's a good idea.

[Roberta]

I think the BetterGro mixes have a reputation for having a lot of fine bits and staying too wet. If you can find bark without the additives it would be better. (Larger "specialty" garden supply stores have it, big box stores don't)

Where do you live? In humid climates, lava rocks work well, if dry maybe less so. (And indoor heating in winter tends to make air very dry) Your goal is "humid air" in the root zone, rather than "wet". There are lots of ways to achieve that.

[Naia]

I'm in NY on Long Island, so we are usually pretty humid in the warmer months and dryer in winter. Although it's been a warmer rainy winter so far. But we have a humidifier running all winter that is actually right next to where the plant lives. So the humidity is usually pretty good in the house.

I'll see if I can find a bark that doesn't have the additives. I did try to use mostly the big bits in the mix, but I can definitely see how it would retain too much moisture. Thank you again!

Oh, do you do top down (or ice cubes) watering or bottom soak? I've been doing a dunk soak for about 5 mins when the top feels dry. But I now wonder if that's contributing to the issue because of the type of potting mix.

[Roberta]

No ice cubes! Unless you can find ice above 60 deg F These are tropical plants. When you water, do it thoroughly - you can hold the plant under the faucet, let the water run through the pot, then let it drain. This does two important things: flushes out "crud" (might help the fungus gnat problem, they feed on rotting organic material , if you don't have it you won't have fungus gnats) and pulls air into the root zone.

Suggest you read through the first few pages of this "sticky" post:
The Phal abuse ends here.

Lots of good information!

[Leafmite]

I have been using 1/4 inch lava rock (it is often used in bonsai mixes) for my orchids, including my Phals. It is a nice alternative to bark as it never decomposes/compacts and continues to allow good air circulation around the roots. Being smaller in size, it maintains more humidity around the roots than the larger size of lava rock which the Phals really like.

If you are watering by putting the Phal under the faucet, make sure that the water dries quickly from the leaves (a few drops of isopropyl alcohol or dabbing with the corner of a tissue can be used to get water from the crown). Indoors in colder climates, if the water sits too long on the leaves or in the crown of the orchid, it can sometimes cause fungus issues. I have not had any trouble with this but sometimes people do.

Good luck!

[Naia]

Thank you!