Weird spots on Calathea

anvar.p25

Hi all,

I wonder if you would be able to help please. By now, after killing and rescuing more than three calatheas, I thought I was doing well when today whilst whipping the leaves i discovered strange spots on my plant. Would you be able to help please? I attach image for your reference and really hope you would be able to help. About the maintenance, it receives fortnightly "showers" and every 10 days a "bath" of 20 minutes. It sits atop of pebble plate to create humidity. I feed it with half strength 20-20-20 fertiliser and only use rain water.

I had the plant in very good condition for almost a year now but all of  sudden the leaves started turning crispy and spotty.

Your help would be most appreciated.

With many thanks in advance

Anvar

anvar.p25

Missing pics

wild edges

I'm no expert but my guess would be over fertilising. A 10.10.5 at half strength once a month in the growing season would be the maximum I'd give it. You might be getting a build up of salts in the soil which is why it could be suddenly happening. They're tough plants to keep happy though and I've seen them growing in tropical houses and still not doing well.

anvar.p25

wild edges said:

I'm no expert but my guess would be over fertilising. A 10.10.5 at half strength once a month in the growing season would be the maximum I'd give it. You might be getting a build up of salts in the soil which is why it could be suddenly happening. They're tough plants to keep happy though and I've seen them growing in tropical houses and still not doing well.

Hi, thank you for your reply. That was my initial thought too so I flushed the soil yesterday thoroughly to see if that would help. Re fertilising it is strange as I am already diluting it to more than half of recommended dose. I shall not feed it for a few cycles to see if that helps might go back to seaweed fertiliser.

Thanks

Anvar

wild edges

It's not that strange when you think about it. They're rainforest plants and rainforest soil is typically low in nutrients. It's better to be cautious and under-fertilise than give them too much as they can't cope with it. Same with water. People tend to get paranoid about watering them and make the soil too wet which does as much harm as it being too dry. The bath you give them might be making the roots too wet too so be careful with that. A moisture meter might be a good investment if you're really keen on keeping them.