leaves turning yellow and dropping, flowers bloom then drop
There are a few reasons why this could be happening. Testing your soil will, likely, help. The pH could be too low or too high. The soil could be too moist. Soils that remain too moist will suffocate roots and invite disease. Alternatively, underwatering can cause this, as well.
I suspect nutrient deficiency in the soil. This can be tested for and corrected. Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-disease-problems.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla
It is in large pot. It’s several years old. Straight stems, and second year it hasn’t blossomed.
Is it in a sunny location? Do you prune it back in spring? If so, have you changed out the soil recently? Container soil eventually breaks down and loses its substance and fertility. If it is too large to easily replace the soil, just work fresh soil in at the top.
Here is more:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/getting-mandevilla-to-bloom.htm
I got my red blooming Mandevilla last year. It just started producing buds, but they all appear that they will be white. What has happened? I want red.
This could be a case of a hybrid reverting to one or the other parents! It could revert back, but likely you may find that it remains white.
In order to keep the red color, it may be necessary to find a true red variety with both red parents, such as 'Crimson Red'.
This collection of articles will help you with the care of your plant:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla
Mature plants, still flowering, have started to get these stick like growth on them. Not thin with leaves like the fines they shoot out, but thick appendeges.
Those are seed pods! You can try to propagate them from seed, but cuttings or tubers would be a better choice.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-propagation.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant-tubers.htm
How do I take care to over winter my Mandevilla in my zone 2-3
You can bring it inside for the winter. Here is how to take care of it:
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/winterizing-mandevillas.htm
Well, you could try to overwinter it in your basement (or inside with no sun after it goes dormant, provide humidity (the inside of homes gets dry in the winter months) and away from air vents) but in my much warmer zone 8, a neighbor that was a frequent grower of Mandevillas experimented, gave up on overwintering and decided to just get another one every spring. The shrub would tend to lose all above ground growth in winter, grow back from the roots and it would take a while to regrow and then to bloom. She preferred getting a new one already in bloom that was blooming and significantly bigger than her overwintered plant would get by late summer.
We are here in Punta Gorda Florida.Just bought a mandevilla. Is it trimable or just let it go
Yes, but this needs to be done right before spring.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/prune-mandevilla-vines.htm
https://www.gardeningknowhow.com/ornamental/vines/mandevilla
I noticed this on my plant. I have examined it with my small handheld microscope and see no pests. If you look closely at the pictures I have attached. The substance always seems to be in the Areas around what look link green perturbances that look like part of the plant. The plant seems healthy. The substance is not silky. It looks more like stringy glue from a glue gun. This plant is indoors.
Hello there!
This looks to be exuding sap! I believe that I might also see remnants of spider mites, or its frass. This would explain the sap, since it will indicate damage. I noticed a few curling leaves, as well.
Look for any webbing, though it isn't always present, and treat with something like Neem oil. Azadiractin is the main ingredient in Neem oil, so you may want to opt for a concentrate. Spider mites are notoriously difficult to get rid of, so vigilance and consistency will be key.
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/azadirachtin-vs-neem-oil.htm