In mid-May, my mother visited me in the already hot, and sunny city of Philadelphia Pennsylvania and helped me establish my very first collection of plants in the 20x20 slab of concrete behind my row home that Philadelphians call their "backyard." The most eye-catching of the five was what a fast climber I later learned to be called a Mandevilla.
About a month after she left, the region experienced a stretch of at least seven or eight extremely hot and sunny days. Philly is always miserably humid in the summer.. but this week saw plain old heat and direct sunlight as intense as any in memory. I was on vacation for half of this period and (of course) my roommate forgot to water my plants. When I came back I noticed signs of stress and a down-turn that are still evident today despite my best efforts. See the photo from right after we planted it as compared with photos from just the other day using this link (in case it doesn't show up in this post) : https://imgur.com/a/NJPNa38 (click to enlarge)
Today, the plant has climbed quite a bit in all directions which I love, but it's clearly seen hard times. I need to establish whether or not the downturn was due to the plant getting too much sun. At this point, I'm thinking no.. because it's been like two or three weeks since that heat, and it's only improved slightly? If at all? Tough to say. The reason I blamed the heat / dehydration is because #1 My neighbor saw me watering my plants out front after the heatwave and she commented that it was killing plants all over the block... and #2 I read online in several places that this plant is not meant to get intense full-on sun all day long. Yes, it likes all-day sun, but not necessarily direct.
Notice in the pictures how the area with the greatest amount of brown/dead leaves is right at the bottom where the roots begin. Does this mean it's almost certainly something in the roots? I know how to check for root-rot.. so I can pull it out and do that if I am advised to do so.. but otherwise I would avoid doing that because, as I have already discovered in my first year of keeping plants, repotting can be stressful for the plant in question. I also read Mandevilla are susceptible to Mealy Bugs.
I also included a photo (in the bottom right of the collage) of this weird green fluffy stuff I found sitting atop the dirt. It's really light and airy and clumpy? lol.. i have no idea what to make of it and sound appropriately amateurish describing it. Just thought it maybe worth mentioning.
I discovered that ideally, these plants are to be potted in soil with a pretty high percentage of Peat Moss.. Well, my mom didn't know that at the time.. She seems to have success with plants without ever doing any kind of reading or new research.. I don't get it. Anyway.. I have two bags of Peat Moss I just bought the other day and I was thinking about doing some mixing today.. taking extra dirt and mixing it in with the Peat and some Perlite perhaps, and then back into the planters.. I wish my soil drained better. Where the heck are you supposed to get earth worms in Philadelphia?
I know this is a lot of information for one super common plant... but it's really an exercise for me to start thinking about diagnoses and what plants need and how to evaluate situations of all kinds. I don't like to do things half-heartedly so when my mother brought me a few plants for my birthday, she unknowingly set in motion a life-long hobby for which I will demand myself to be knowledgeable and detail oriented! Thank you so much for reading!