Rhopalostylis Sapida

[xtazia]

Just planted this Rhopalostylis Sapida palm (15 g) in ground today. 
 

yellowing on fronds - is this an indicator of nutritional deficiency ? What can I do to fix ? Sulpomag ? 
 

also not sure what this dark area is - I can scratch it off. Is this normal for this species ?

[Josh76]

Had it been living indoors until you planted it out? I could be wrong, but it looks like a bad case of Red Spider Mite.

[Jdash]

mites love this thing

[xtazia]

8 hours ago, Josh76 said:

Had it been living indoors until you planted it out? I could be wrong, but it looks like a bad case of Red Spider Mite.

nope it's been outdoor.

[Darold Petty]

The yellow splotches in the first image are severe potassium (K) deficiency.   This is the most common nutrient deficiency, as K is water soluble and is leached out by irrigation.  Use a broad spectrum fertilizer, ideally with the macronutrient ratio of 3-1-3 for the N-P-K.  You can also apply an organic called greensand (gluaconite) for slow release.  This has the advantage of being very safe, with no risk of overdose.  The affected foliage will not recover, but the new growth will eventually be free of this problem.

[Foggy Paul]

Darold's suggestion of greensand is what fixed it for me. I haven't had this on a Rhopie, but a Howea belmoreana and a Chambeyronia hookeri were badly affected and both look much better a year later. Buy a good sized bag, it goes pretty fast. You will have better results if you can work it into the topsoil (I have heavy mulch and it worked eventually).

[xtazia]

3 hours ago, Darold Petty said:

The yellow splotches in the first image are severe potassium (K) deficiency.   This is the most common nutrient deficiency, as K is water soluble and is leached out by irrigation.  Use a broad spectrum fertilizer, ideally with the macronutrient ratio of 3-1-3 for the N-P-K.  You can also apply an organic called greensand (gluaconite) for slow release.  This has the advantage of being very safe, with no risk of overdose.  The affected foliage will not recover, but the new growth will eventually be free of this problem.

Would palmgain also work ? I have a bag of that, but I just planted this palm about 3 days ago. I read to wait until the palm is more established on fertilizing. 

[Darold Petty]

Palmgain is an excellent product.  Frequent light applications of fertilizer are better than infrequent, heavy doses.

https://edis.ifas.ufl.edu/publication/EP273

 

[Jonathan]

On 10/11/2025 at 6:25 AM, Darold Petty said:

Palmgain is an excellent product.  Frequent light applications of fertilizer are better than infrequent, heavy doses.

https://edis.ifas.ufl.edu/publication/EP273

 

Great article Darold, thanks for posting.