Ask around and you'll probably hear people say Plumerias do not like allot of water. While this is true, its only during certain times of the year your plants do not like moist soil. During winter, Plumerias go dormant, they loose all their leaves and most likely will not bloom. They do this because of the cold temperatures. Any area that gets below sixty degrees will cause a Plumeria to go dormant. During this time, Plumerias require little to no watering at all. I check all my Plumerias regularly throughout the colder times of the year by sticking my index finger as deep as I can into the growing container to check for moist soil. I do this because although the top layer of soil in the container may be bone dry, the inner core may still be moist which means I do not have to water my Plumerias. Checking your plants regularly this way will help prevent over watering and thus potential rotting of your plants.
However, as soon as summer comes around the corner and temperatures are up into the high seventies, eighties or more. Its time to start watering weekly. I have a set watering schedule for all my plants. I water once a week on Fridays and do not water until the following Friday. This works for me as the soil my Plumerias are grown in does not dry out quickly due to the area they're grown in. If you're growing Plumerias in full sun, in over a hundred degree temperatures, then you may have to water on a daily basis. I apply the same method of checking of checking for moist soil that I just discussed, during the summer as well.
When you water a Plumeria, the goal is to drench the growing container so water seeps out of the bottom drainage holes. Just spraying the top layer of soil in the growing container is not enough. You could be potentially under watering your plant which could lead to root damage due to the soil drying out in the inner core of the container.
If your Plumerias are blooming make sure you do not spray any inflows with water. They are very sensitive and can be damaged easily. Misting flowers or inflows is not necessary at all. You can however spray your Plumerias leafs with water, but I recommend doing this at night or in the afternoon right before the sun is about to go down. Spraying or misting Plumerias leafs during the day in full sun can cause sun burns which could badly damage leafs.
Although the methods discussed on this page have worked for me, they may not work for you. Growing Plumerias successfully is all up to you, the grower. I'm not responsible for any damages that may occur as a result of following my methods.