I bought my first Plumeria 3 weeks ago. It was called Mary Susan. Everything I read and what I was told at the nursery is that they like direct sun and the more the better. However, if I have my plant out in the sun, the flowers and the leaves literally flop. Even if it's a cloudy day, if it's bright, they flop. Within a few hours of it being in the shade, everything perks back up. Also, in the beginning the petals had bright pink rims. Now, the pink is completely faded and the flowers are just white with yellow middle. It's also a very windy day today and all of the flowers other than one newest one fell off. Any ideas?

Plumeria do best in full sun even here in Florida which is a harsh environment. It they are flopping in the sun they are not getting enough water.

I was told to water it once a week unless it rains. It's been raining so I haven't been watering much because I was concerned about the roots rotting, but maybe it didn't get enough water from the rain. Is once a week ok if I actually water it regardless of rain?

Also, could the change in color have to do with watering too?

No, I would definitely not wait a week to water in the summer heat here in Florida. If your plant is already well rooted, it won;t rot. That is usually only a concern when a cutting is trying to root.

Blooms can change color like that. As they age they can fade.

Ok. I watered it thoroughly on Saturday. It was raining a lot over the weekend so I had it on the patio but I just put it back outside this morning. However, it dropped all of its flowers over the weekend. One That had just opened two days prior. Could that be due to watering too? There are new buds coming in.

I am a plumeria n00b (relative to many people on this forum), but my understanding is that the flowers only last a few days each. This has been my experience with my flowers the last 2 years.

Yeah flowers don;t last long.

One more development. As I said, I watered it, and I've been giving it morning sun. Now the little stems were the flowers fell off are black and it looks like some of the tiny buds are turning black.