I planted a store bought mandevilla that had some bloomed flowers and hung it at a sunny place.
A week later I noticed that new buds turned to brown and never blossomed.
Is this some kind of a desease or is there anything I can solve the problem?
Thank you in advance.
Thank you for contacting Toronto Master Gardeners.
Mandevilla is a tropical plant. When Mandevilla buds turn brown and drop off, it is often a sign of excess cold exposure. These plants do not tolerate temperatures below 7 to 10 °C . Perhaps, overnight temperatures in your area fell below this level after the plant was placed outside?
Another possible cause of bud browning is over or underwatering. Since your plant is in a sunny place, the soil may have dried out too much. These plants like evenly moist, but well-drained soil.
I suggest that you move your plant to a partially shaded location, or an area with morning sun, and carefully monitor the soil moisture level. Do not allow the soil to dry out, but make sure it is not too soggy. Your plant pot must have drainage holes, and these must be properly functioning.
There is a useful fact sheet on growing Mandevilla at the Clemson Cooperative website at: https://hgic.clemson.edu/factsheet/mandevilla/
Good luck with your Mandevilla.