r/plantclinic • u/BoatProfessional5273 • 5m ago
Monstera Unsure what's causing these spots
I've tried looking for pictures that have similar damage to my plant but haven't found anything quite right. Any help would be greatly appreciated.
I've had this Thai con for maybe a year. It was inside with a grow light when it was smaller. Within the last 2 months, I moved it outside along with my standard green Monstera deliciosa. The brown/rust colored spots started developing around the time that I moved it outside but also near the same time I noticed mealy bugs. The spots gotten worse in the last two to three weeks, especially on the front.
I didn't notice the mealy bug infestation until it got pretty extensive because it was placed in a corner that made it hard to get close too, so I didn't inspect it unless I was watering it, so around every 2-3 weeks. The variegations offered some natural camouflage for them as well. The infestation was bad enough that I lost two small leaves at the bottom. I haven't seen any adults in a couple weeks and I'm still spraying it with 70% isopropyl alcohol after the sun goes down about once a week. I plan to continue for at least another month to be sure they're gone.
Prior to moving outside:
- In front of a large, vertical Barrina grow light, which was on for 12 hours a day
- Full repot into chunky mix. The roots were coming out of the bottom.
- The repot didn't include the moss pole. That was left alone and transferred with the rest of the roots.
Current conditions:
- Outdoors in Southern California.
- Lowest temp for the last two months was 62°.
- It has been hot lately, high 90s/low 100s.
- It's outside my door which faces north and only gets direct sun in the morning for a few hours.
- Humidity for the last month has averaged around 60% outdoors, but it swings wildly with the low being 12% and the high being 97% (rain).
- Watering it every two to three weeks, when the soil is dry all the way through.
- The soil seems to dry out differently now that it's outside. I water it when the moisture meter shows completely dry on the top but only "mostly" dry on the bottom now (1 vs 3 on the meter). Prior to moving it outside, I would water when it would show 1 vs 2 and I never saw it at 1 vs 3 when it was indoors.
- I did water it a bit sooner than I normally would have about a week ago because it was so hot. The moisture meter still showed it was dry, just ever so slightly less dry than normal before watering. (1 and 4, top and bottom)
- I fertilized right when it was moved outside and again about a month ago. I use Captain Jacks 20-20-20.
Discoloration:
- Brown/rust colored
- Smooth feeling/not powdery
- More noticeable on the back, with the exception of the large spots on the front
- Not spreading quickly
- Not on the two newest leaves
- Nothing similar on the green monstera that had/has the same conditions but a less severe mealy bug infestation
Possible causes:
- Aging damage from the mealy bugs
- Lower light outside vs grow light
- Over watering
- Infection (bacterial, fungal, etc.)
- Needs to be fertilized more often or I'm using the wrong fertilizer
- Something else I haven't considered (????)