I actually just moved mine to a shadier location because of the same problem. They don't seem to do their best in direct sun. I keep forgetting these and my Marantas always look best in what I would normally think was too dark of a room. Try it in a well lit room away from the grow lights and see if the colour comes back.

I would like to know the ratio of using coffee grounds and sugar for my houseplants!

Here is a link that might be useful: Coffee time with Friends

Hi Andrea, welcome to Gardenweb. In the future, it's best to start a new discussion for a new question. I've not heard of anyone using those materials for potted indoor plants.

It's getting worse even in lower light. Grr...

I have not checked inside the pot but these roots look healthy. Repotted just in July.

It's been growing a leaf here and there all winter long, and now there are 5 new leaves shooting up. (Three visible here, one on the right, two smaller ones on the left.)

I really wonder what the yellowing leaves mean. :-/

This post was edited by greentoe357 on Wed, Apr 2, 14 at 7:48

I think the exposed roots coming out of the holes are the problem. I would repot.

greenT,
don't worry - it's normal for old leaves on calathea to yellow in spring, before the new growth pushes out.
it grows from the rhizome - last years leaves will have to go.
your plant in 1st pic looks smashing for this time of year.
my stromanthe yellowed/dried up old leaves too (the ones that were from last springs growth, but it kept the leaves that grew in summer/fall).
i cut them off only when they turn totally yellow. just let them decline slowly, while the new ones are pushing out. the plants are just waking up. let it be. there's no need to repot, unless the tips of new growth are pushing against the rim of the pot and have no room to expand.
i assume you're feeding still. so continue. don't move it away from light ;). it should be getting MORE light come spring, not less.

> I think the exposed roots coming out of the holes are the problem. I would repot.
> there's no need to repot, unless the tips of new growth are pushing against the rim of the pot and have no room to expand.

I should slide it out of the pot and see if it's root-bound, I guess. But it was only repotted in the summer, I can't imagine it's full of roots after a winter (not the fastest growing time).

> it's normal for old leaves on calathea to yellow in spring, before the new growth pushes out.

I hope very much you are right. There is much more new growth being pushed out at the same time now than what was happening in the winter.

Pruning old leaves is sort of an issue. I can't help but leave a dry stump. Maybe those will be easier to prune lower if the plant if in my hand with little soil on top (at repotting, in other words).

Another Calathea (ornata, in the picture) has a couple leaves drying, but it's not bad. New leaves are also coming out of that one.

> i assume you're feeding still. so continue.

Yes. Considering increasing the fertilizer dose to all plants now that spring growth is happening.

> don't move it away from light ;). it should be getting MORE light come spring, not less.

Yeah, it was ok the whole winter under that light, so I think it should be fine.

Robebuddy, are you reading all this as well? How is your Calathea doing?

As long as we are on the topic of Calatheas, Calathea makoyana is a princess for sure when it comes to humidity. It lived the whole winter in a plastic bag. Then at some point I took it out for a few days, and THIS happened. But new leaves are coming up on that one as well, as they were a few times all winter.

Before I knew anything about plants and specifically about covering them up for humidity, I bought a Calathea roseopicta, and that one died like this pretty fast in the fall, desiccated. I am going to try that one again for sure. Who needs flowers when you have leaves like THAT!

often the roots will come out of the bottom of the pot looking for extra moisture, but inside the pot the root ball will not necessarily be fully knitted. since the bark is fine for sev years, you can safely just uppot to next size up, IF the root ball is full.
i'll advice to put it in a 'triangular' short but wide pot, sort of like they use for hanging baskets: with very narrow bottom and very wide top. see which way the new shoots are growing - and plant it so that there is room for the rhizome to extend in that direction a couple of inches.
keep the leaves on until they yellow completely. you can trim the stalk later, it will dry up in time, when it'll crisp, you can pull it off cleanly at the stem (before that it refuses to detach).
my humidity is 65-70% even in winter and still i got a few brown spots on my strom.

Thanks, Petrushka.

> keep the leaves on until they yellow completely. you can trim the stalk later, it will dry up in time, when it'll crisp, you can pull it off cleanly at the stem (before that it refuses to detach).

This is exactly what happened just now. A stalk was completely dry, and it came off cleanly and easily when I pulled lightly.

> my humidity is 65-70% even in winter and still i got a few brown spots on my strom.

WHAT? HOW? In our zone? My humidifier has been huffing and puffing all winter, but I'd get 35%-40% at most for very long stretches of time. The only place where I can have higher humidity is bagged or in a plastic-covered container.

well, :)... i do have LOADS of plants (3 gigantic fl to ceiling windows: 10', 7' and corner fish-bowl 7'-14'-5'). and a lot of plants are very large and a lot of others are on self-watering wicks - so medium is moist. all that plant mass keeps the humidity up. i have temp/humidity meters in all rooms so i check and know exactly what is happening where.
and in all of these windows ...wall to wall plants almost up to 6'-8' high. soon as i stop heating, the humidity goes up to 70%-75% and in summer of course it's 80-85% most of the time.
i had to take my aralias indoors last summer for a week or so, 'cause on the balcony humidity was dropping to 40% many days... it was very weird,tell yah!
in a word - it's a jungle here ;).