Windmill palm is not looking well :( Is this leaf scorch?

[PashkaTLT]

Hello,

I got this 5G windmill palm a few months ago, planned to plant it on my backyard this season.

However it's not looking well at all

Is this leaf scorch?

- The palm stand in a relatively dark place (should I add artificial light for it?).

- I don't think we overwatered. Perhaps underwatered a little? However it's winter, so the humidity is low. 

- We didn't fertilize it, but it came with a fertilizer added already.

- There were no extreme heat, cold or cold drafts.

If this is indeed leaf scorch, does this plan look good?

- I'll get a longer soil moisture meter to make sure it reaches close to the bottom

- Add a little bit of potassium fertilizer

- Flush salts/fertilizer burn — Water heavily several times to leach excess salts

- It's hard to find a place with more light in my house where it would also be inaccessible to my all-destroying parrots. SHould I add some artificial light?

[happypalms]

Overwatering symptoms! 

[Allen]

Could be too much fertilizer as well, in future only use Osmocote plus indoor/outdoor on that pot.   That palm is not growing well enough to take non slow release fertilizer.

[PashkaTLT]

On 3/22/2026 at 6:38 AM, happypalms said:

Overwatering symptoms! 

Can you please explain the difference in symptoms between overwatering and leaf scorch?

On 3/22/2026 at 12:19 PM, Allen said:

Could be too much fertilizer as well, in future only use Osmocote plus indoor/outdoor on that pot.   That palm is not growing well enough to take non slow release fertilizer.

I didn't mentioned, but they put slow release fertilizer. Can it still be too much fertilizer even if it's slow release, or it makes it unlikely?

[happypalms]

20 minutes ago, PashkaTLT said:

Can you please explain the difference in symptoms between overwatering and leaf scorch?

I didn't mentioned, but they put slow release fertilizer. Can it still be too much fertilizer even if it's slow release, or it makes it unlikely?

Sun burn is in necrotic patches where the leaf has been exposed, or are you talking about fertiliser burn, the leaves will curl up and the ends will start to look necrotic slowly or fast depending on how over fertilised the plants are, going black. 

[PashkaTLT]

1 hour ago, happypalms said:

Sun burn is in necrotic patches where the leaf has been exposed, or are you talking about fertiliser burn, the leaves will curl up and the ends will start to look necrotic slowly or fast depending on how over fertilised the plants are, going black. 

I thought sun burn is just a specific and infrequent case of leaf scorch?

By the way, after reading more on leaf scorch, it seems like leaf scorch, overwatering and overfertilization are related? Because according to wikipedia, for example, leaf scorch can be caused by overwatering and overfertilization. Maybe that's why the symptoms are similar...

[happypalms]

14 minutes ago, PashkaTLT said:

I thought sun burn is just a specific and infrequent case of leaf scorch?

By the way, after reading more on leaf scorch, it seems like leaf scorch, overwatering and overfertilization are related? Because according to wikipedia, for example, leaf scorch can be caused by overwatering and overfertilization. Maybe that's why the symptoms are similar...

You could say sunburn is physical damage, both overwatering and over fertilising are similar in appearance, leading to a misdiagnosis. You say you have not fertilised your palm yet it came with fertiliser. Assuming that the fertiliser it came with was a mild one then one would go with overwatering, and by trying to leach out fertiliser this will make matters worse, unless you have a super good draining mix. It looks like overwatering yet your concern is fertiliser by wanting to leach the soil. I work on farm and everything we do is written down, this way any problems later one we can look at our spray, fertiliser program and come up with a diagnosis. In some cases human error is to blame. And overwatering and over fertilisation is generally human error! Ask yourself what you have done wrong and make a conclusion, water or fertilisation? 

[PashkaTLT]

Thank you.

If I were to choose between overwatering or overfertilization I'd go with overwatering. We think we didn't overwater it, but considering it was in a dark place, it probably didn't drink enough and we could have overwatered it. We had a soil moisture tester, but it wasn't too long. Today I received a new one, with 12" probe (15-16" total length), hopefully it will help check the bottom of the pots and avoid overwatering.
I've also moved it to a brighter spot, as bright as it can be here at 40 degrees north latitude in March (not bright :))

Could it be K (potassium) deficiency though? I think it has similar symptoms?