Help me diagnose my plumeria!
Greetings fellow gardeners!
I need some help with a yellowing leaf issue with my NOID plumeria. I'm in zone 9 (central FL) and this is my one and only plumeria. It was gifted to me late last summer so this year is my first full growing season. Last year i transplanted this guy into Al's 1:1:1 gritty mix and i use 1/4 tsp Foliage Pro every watering (rain water). I currently have him in my covered lanai (east facing approx 5 hours of morning sunlight) and water him about every 2-3 days depending on the weight of the pot. The plant is potted in a ceramic pot as well. My issue is constant yellowing of lower leaves. The plant will grow 1-2 leaves but then lose 2-3 leaves shortly after. Upon doing research online the only issues that seem to cause this are pests (spider mites) and/or over watering? I feel i have a good grasp on watering with the gritty mix as most of my succulents are growing in it and doing well.
Approx 4 weeks ago, this plant was on my front patio, uncovered and west facing. My initial reaction was it was getting too wet from the rain (would be strange for plumeria to have this issue with gritty mix IMO) or maybe too much direct sunlight mid day/afternoon. This is when i moved the plant to the back lanai to receive less light and control the moisture entering my potting medium. At this point I also decided to spray with my mixture of neem oil/ rubbing alcohol and dish soup to kill any potential pest residing on the plant. The next 2 weeks or so, it grew 2-3 new green leaves and didnt drop any old ones. 2 days ago, I noticed yellow/green discoloration on one of the leaves. The next morning it dropped and by that afternoon 3 more were completely yellow (pics below)
Can anyone help me diagnose my issue. I've inspected thoroughly and can not for the life of me find any spider mites or other pests!
Please help =)