"Could (fertilizer spike) be why the leaves started yellowing in the last 24 hours?" Very possible. Right next to the fert spike, there's 100% fertilizer, if you know what I mean. Too much fertilizer is toxic, like a person taking too many vitamins.

"Should I attempt a re-pot?" I would just take the fert spikes out, (other plants too,) unless there's other reason to think repotting would help. How long has it been in its' same pot?

"I guess they've dissolved by now???" IME with these, that's pretty much impossible. The last time I tried one, I found it after many months when repotting. It had turned into a weird gummy worm, but not dissolved or smaller.

I've only had a Cal for about a year, but it was much happier inside for winter, east window. Since going back outside for summer, it's shrunk by about half (in number of leaves.) Our house is pretty unusual though, cooler and more humid than most indoor spaces during winter. 50% is not terribly low, I suspect this plant just doesn't like heat. Since it's cooled off, a new leaf has formed, though still outside. Curious to hear what others have to say too.

Are you able to add a pic?

I looked again even more thoroughly for the fertilizer spikes and found one. I'm thinking I had put in 3 (which was less than what was recommended for my size pot), unless I was even more conservative and only did one (since I was feeling sorta skeptical anyway..."would this fertilizer really help boost the plant health?" So, if there were 3, I don't know what happened to the other 2, but they should be thoroughly mixed in the soil because I sifted through all of the dirt between the sides of the pot and the root system.

It's been in this pot since spring when it had outgrown the original pot (from the greenhouse a year prior)....

It's in our bedroom which is one of the coolest rooms of the house... I could move it to the living room for an east facing window....but there's not normally a humidifier in that room and it would at times be warmer than the bedroom usually is. Or would a pebble tray/water be sufficient?

I appreciate any input and hearing of other's experiences.

In this post, I'm including an overall picture, though, the plant is much less full than it was a month ago. :( Oh, and I wanted to mention, too, that I had read that the brown edges could be trimmed carefully (with the shape of the leaf) with a scissors, which I did this morning. Hopefully that advice wasn't too far off. :( Sure did make the overall plant look better for the time anyway. :)

I'll post a few more pictures.

Here's a collage of a few more photos....2 are of 2 different yellowing leaves, another is of a random brown spot on a leaf and another is of a browning edge that I didn't cut off....

Welcome Sovory,

Ditch the fertililzer stakes. They only fertilize areas they're inserted.

What size was its previous pot..what size is the new pot?

Calatheas do better when a tad root-bound.
Yellow leaves usually indicate over-watering. If the container is too large and mid to lower soil remains wet, leaves will yellow.

Brown, crispy leaves means low humidity and/or too much heat/direct sun.

My Cals are 8' from west and north windows. At night, they get a little artificial light, 'although I haven't yet turned them on.'

Calatheas are fussy plants. Fussier than kitty-cats. :)

At the conservatory, Cals are grown in a semi-cool room, on the ground, near a large pond. Tall plants prevent direct sun from hitting Cals.

Trying to duplicate a conservatory via a house is difficult, if not impossible...
Oh, adjacent my Cals is an indoor fountain/waterfall.
Cals are placed on pebbles with a little water in the saucer, and misted..

During winter, or once days shorten, I let soil dry out. Not as much as say, a cactus, but soil is crumbly and container light in weight.

I hope the Cal isn't your first plant???

On last comment. Of all Calatheas, the variety you have is most difficult.
I gave up buying Roseo-Picta types..lol.

It's true, cutting brown leaf edges and leaving about 1/8" of brown on should prevent spreading.

Good luck, don't give up... Toni

Hi Purple!!

To Hopeful...

I don't recall what size the first pot was exactly....I'm thinking 6-8" in diameter. the current pot is about 12" in diameter and maybe 12 " deep. Do you think it's too large?

What do you consider low humidity and/ or appropriate humidity for a cal?

I guess it's somewhat comforting to know this can be a difficult plant. I received it as a gift. It's not my only plant...I also have peace lilies, small palms, and diffenbachia...and a struggling along African violet.

I'm glad to hear cutting the brown off wasn't a bad thing....

Thanks for your input!

Also, hopeful...

....you mentioned if the mid-lower soil remains wet, leaves will yellow....so could it stay in the same pot if I would just wait until the top is much drier before I water?

Also, for whatever it's worth, when I was digging around trying to find the spikes.....there is only about 2 and 1/2 inches of soil between the roots and the edge of the pot.....is that maybe too much, though, to be considered "root-bound"?

Hi Sovery,

When your Calathea was in its old container, the pot was too small, 'roots squished, sticking out of drain holes and top soil,' especially since the new pot is almost twice the size of the old pot??

Tropicals like 100% humidity, lol, but we can't provide them this luxury.
Too low would be anything below 30%.

Do you have a hygrometer? Hygrometers are great..usually, they display temperature and humidity levels.

If the roots are only 2" smaller than container, there's no need to pot...unless foliage continues yellowing.

It'd be great if our homes could be kept humid..Imo, humidity is most important when it comes to Cals.
Proper watering, too, of course.

To be honest, your Cal looks great. There's a little brown, but since it was outside, it'll take time to acclimate indoor climate.

Thanks again for your input.

I thought maybe I should post an update, since I'm afraid things are still going downhill. :(

We have this little desktop station clock thing that does display temp and humidity.....it seems to run about 5% higher than what the humidifier reads, so one is obviously a little "off" (or they both could be a bit wrong, I suppose).

I'm starting to wonder if it's really getting enough light. What would be indicators that it's not? I'm posting updated pictures....the left column are from 3 days ago, the right hand column from just a bit ago. And more leaves have started to yellow. :( And some (not all...yet, anyway) edges are starting to turn brown again......:(

The humidity in that room has been between 55% and 65% (according to the humidifier) this entire time, but we've had a lot of clouds and some rain this week. I haven't watered it all since the beg. of the week. Even so (when it is sunny outside), I wonder if it's getting enough of light. Would moving it to a room with a east facing window with maybe only 50-60% humidity be a better option? Or I guess I could move it to a room with both north and east facing windows, but that's our daughter's bedroom and so #1--we wouldn't get to enjoy it much there, plus, #2--the blinds are closed a few hours every afternoon for naptime. :)

What do you think?

Morning Sovery,

As I mentioned above, your Cal needs acclimating since it was summered outdoors.
Think about it. When plants are outside, they get fresh, circulating air, and 'depending where one lives,' humidity.
Then comes fall..plants are moved in a stuffy, dry house.
Plants should be brought inside before heat is turned on. Especially, tropicals.

Did I mention, Calathea picta types are very difficult? I have two..one is in a terrarium, the second is on its own.
Yours is a picta..sorry don't know which variety.

Some Cals are fussier than others. For instance, my C. Snake has brown tips; C. Peacock doesn't.
When outdoors, they sat side by side..hauled indoors the same day. Same light, etc.

Indirect-bright light is perfect. During summer, west/south windows are way too harsh.
This time of year, 'at least here in IL,' s/w exposure wouldn't matter....won't burn leaves.

Your east window sounds okay, as long as your Cal isn't 10' away. lol
If you're worried about light, why not add artificial? You can do so inexpensively.

Hygrometers..lol..Buy a second to compare. lol. We have three. Two are the same type..purchased years ago..accurate temps and humidity.
The third was bought 7-yrs ago..it reads inside, outside and green house temp.
Every fall I place all 3 side-by-side to compare readings. One may be a degree higher...but I consider 1 degree good enough. :)

55% humidity is great.
What about temp? Is the room warm/hot?
Cals do not like too much heat. My Cals are in a fairly unheated room. In fact, during cold months, the room gets pretty cold. Sometimes, too cold.

Fresh air is important. Do you have a ceiling or rotating fan? If so, can you run it an hour or two a day?
As long as air isn't directed on your plants for more than a few seconds at a time.

Wish I could be more help...Toni

Hopeful,

Any particular type of artificial light?

The room is one of coolest rooms of the house...we don't heat it at all except for what heat makes it's way in when we forget to close the door. :) At times, it does feel a little warmer just because of the higher humidity.

What is a sign of too much heat (if I opt to move it to the other room)?

Any signs I should look for of too little water (signs that will appear before wilting)? I'm thinking I need to water it less maybe, but don't want to go to the other extreme.

There is often a fan running in that room, though not ceiling or rotating.

Morning Sovery,

Light. I use different fluorescent light bulbs.
On a shelf that holds 3 bulbs, 'per tier,' each bulb is regular shop lights purchased at HD..inexpensive.

Where succulents are placed, the hood holds two bulbs..Both bulbs are 'gro-lights.' 20.00 per bulb.

In the back plant room, the hood holds one cool white and one warm white fluorescent bulbs. Inexpensive.

When I say hoods I mean shop lights that hold bulbs. Hoods are inexpensive..

All in all, the entire setup can be purchased, at the minimum, $20-25.00.
Depends what you like, style, etc.

On one table in the LR, I keep a few plants under a regular 75 watt light bulb..

All plants under/near lights are before a window, so they're getting sun, or what little sun we get here in IL, during winter. :)

Your Calathea should like a cool, humid room..
But, if there's an icy leak near a window, Cals will freeze.
Temps between 65 and 68F are ideal.
70 and up is okay, as long as there's humidity and fresh, circulating air.

Too warm is 80 and higher...along with dry air.
If soil is kept muddy, there's a good chance your plant will get root rot.

Testing soil is easy. The easiest way with small plants is lifting before and after watering.
When a plant is watered, it'll be heavy in weight..When dry, the plant is light in weight.

Another way is insterting a thin stick, deep within soil. If stick comes out muddy, center to lower soil is still wet, even if top soil looks dry.
If the stick comes out dry, it's ready for a drink.
Water, not alcohol. lol.

Ever bake a cake or muffins? If you have, did you ever insert a tooth-pick to check for doneness? Same concept.

I find daily misting helps...and setting Cals on a layer of small stones/pebbles. Add water below saucer bottom.

Toni

Have you tried a humidifier ? Since Calathea likes humidity .