This year, I bot a new Mandevilla plant from another nursery, and it is developing the same problems. Leaves turn yellow seemingly overnight, and either drop off of I remove them. There also now appears spinder-like webbing on the few new shoots which have caused the new growth to blacken and shrivel. Plant probably got too much water with all the rain we've had in CT, so took its saucer away. Also looks like little white dots on the underside of one leaf. Any way to stop the death of this expensive plant?
Yellowing leaves can indicate pests as well as watering issues.
With the addition of webbing, your plant likely has Spider Mites.
Treat the plant with Neem Oil.
These links will help you.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
Deer ate all flowers most of the leaves will it live what can i do
Move it to a safe area if it is a potted specimen.
If it is in the ground, try to place a fence or barrier around it to keep it from being eaten any further.
Just give the plant time to grow and if enough of the plant remains with healthy roots it should continue to grow.
I cut my mandevilla back and wintered it inside. When I moved it outside it has put on beautiful leaves and has grown but no blooms. What did I do wrong?
This article will help you.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
Last week I went out and all the flowers on my mandeville were wilted . And with in a few day the whole plant is wilted looking. I don't see any holes in the dirt around the plant for moles or voles please help. Thanks. Rosemary
Is the soil excessively wet or dry?
Do you see markings on the leaves?
Yellowing of leaves?
Root rot can cause sudden wilt along with plant that is too dry.
Pests and disease could also cause sudden death of a plant.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
I live in Central Florida. I just planted 2 mandevillas in pots outside my front door. They get the morning sun until about 2 in the afternoon. One is doing great with new growth and lots of pink blooms. The other is sagging or drooping or wilting. They are in the same location, in the same size pot and soil, getting the same amount of water.
Even in the same growing conditions, plants can grow differently.
Make sure the soil is well draining. The containers can be 'lifted' from the ground to ensure excess water is draining.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
Hello I have had the Madevilla vine plant for years in a flower pot for years. I buy them and plant them news each year. We put the wet ones this time and added those to the back ones in the front of pink they are doing wonderful. The ones in the back are red one already dried out and died the second one now is has flowering but the plans are yellowing is it going on it looks like if it's lack of water but that's not the issue. Any recommendations?
It does look like the container size is small for the plant size.
You may have overcrowded roots. This can cause the plant to die out. They can't take up water and nutrients are lacking with little soil content.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
Hi, I bought two Mandevilla plants back in December 2016. I planted them right away and for the first few months they were doing great. In the last month or so the heat in Southern California specially the San Fernando Valley has been pretty bad. On of my beautiful Mandevialla seems to has been burnt badly. The other one is kind of OK. Can the this one be brought back to life? Thank you, Amy
The heat was likely quite intense and stressful for the small plants.
You can try shading the plants, especially during the hottest part of the day.
Make sure the soil is moist; slow and deep watering.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm