I am having a problem growing the mandevilla in the ground. Is this plant an acid loving plant? They die a slow death. I have one in a pot and it doing great. Hugh. But it is on our patio with a slated cover. The plants I am having trouble with are in the ground, and also in afternoon sun. JIM
Most likely, it's the sunlight that's affecting them. These plants resond better to filtered light or shade rather than full sun, especially in the afternoon when it's more intense. If possible, you may want to relocate them or in the very least water them more often to keep their roots cool. This article may help: https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
I plant a Mandevilla every year on my patio. This year the plant is doing great, but has no blooms.
If your nighttime temperatures were consistently cool this spring (or if they're still very cool), or if the daytime temperatures have been ridiculously hot, those could be some reasons you don't have blooms on your Mandevilla. Generous watering is required as well. This article may help you: https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
Why doesn't my mandevilla bloom?
Here is a link that will help you.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
I've noticed little white specs on the new growth. Is this a bug and harmful to the plant? If so, what is the remedy?
Sounds like you have a Mealybug infestation.
This link will help you.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-pest-problems.htm
I live along the NJ coast line and purchased 3 burgundy mandevilla plants. They are not the climbing type and they are not mounding type. They seem to just stand upright about 18"-20." Planted them after Memorial Day and they were doing fine. They receive full sun for about 4 hours a day. However, in the past week the new blooming flowers are blossoming white. Not a nice white. A sickly white. The buds look burgundy before they bloom. There are no yellow spots and the leaves look dark and green. I use a watering can to water them once a day and have not yet fertilized.
I'm sorry your Mandevilla isn't doing well! There are a number of issues that this could be, but this article may help you: it describes some common diseases that Mandevilla get, and how to treat them (if they can be treated):
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-disease-problems.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
Our Mandevilla plant is growing very well. What should we do?
Enjoy it!
In case it's a typo and you are actually having trouble with your Mandevilla, here is a link that will refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
I overwintered my 2 Mandevilla plants in my basement. In April I placed them in the sun room and they started growing. In June I placed them back on the deck where they were beautiful last year. They continued to grow vines, but no flowers and it's now July! What did I do wrong? John
These links will help you get your plant blooming.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-blooming-season.htm