Howea Belmoreana yellow/brown tips + pest infestation

[storch77]

Hello everyone! First time poster, long time reader here 

First off, some background information: I was lucky enough to get my hands on this howea belmoreana about three months ago. I live in Germany, usually they only sell the Kentias here. The soil was very wet and dense (stayed wet for over two weeks even during the late summer heat), so I repotted it a month later into a mix of 45% soil, 40% clay granules and 15% pine bark. So far, I've kept it in a corner about 4.5m (about 14 feet) away from a south facing window front, so it doesn't get a lot of light, but I read that Howeas can handle low light conditions fairly well. I moved it away from the light into that corner gradually over two weeks.

Now two issues have arisen for me:

1. It had a minimal amount of brown tips when I got it, but after a while it started increasing (photo attached). I'm assuming it's a watering issue, but I can't tell if it's over- or underwatering. If it was just dry brown tips I'd say underwatering but they also look yellow in a lot of places, so I'm unsure. The soil mix now is super airy and lose, but still holds on to moisture for 10 days at least (I assume because it doesn't receive a ton of light). It's not wet, but when I stick my finger in it, it still feels humid two inches down. I tried waiting for it to dry more, but I felt I had to water it because of the yellow/brown tips. That was every 10-14 days. 

2. Unfortunately, it came with an infestation of scale (it also had spider mites but I seem to have gotten rid of those). With the scale, it was only a few ones in the beginning which I picked off by hand, but it has gotten a bit out of hand. I've had good experiences with insecticide sticks (not sure if they exist elsewhere: a combination of insecticide and fertilizer, you stick them in the soil and they dissolve over 3 months when watering). But now that we're approaching winter, I'm unsure whether I might overfertilize it when using them in October. How do I go about this?

I'd be thankful for anyones two cents on these issues. I love this plant and I don't want to lose it. If you have any questions let me know! Thanks!

Photos:

Edited October 19, 2020 by storch77

[piping plovers]

That’s a good looking palm!  Sounds like you did the right thing potting it in the new aerated mix.  On the tips, I get those at times and if they are not in the newest fronds I generally do not worry about them.  Might be residual damage from the previous soil conditions.  For scale, I use the ortho systemic granules.  Some on here have recommended coffee grounds in the soil; I have not seen scale lately but will try that next time.  Best thing for scale is putting plant outdoors in summer but since we are heading into winter I know that is not helpful now. Be sure not to overwater in the winter months; maybe discern how heavy the pot is freshly watered and then when really needs water.  Looks like a big pot so maybe a lift test if you are comfortable with that. Best of luck, keep us posted.

[storch77]

Thanks for your reply! Unfortunately, the yellowing tips also appeared on the newest frond. I'm worried the roots might be rotting, but i'm also worried of damaging the plant further by disturbing the roots. What would you suggest?

[Pal Meir]

Leave it as it is, keep it moderately cool, don’t overwater! Winter is coming, but indoors it might be too hot.