Question
Dear Madam,

I transplanted a red dipladenia with blood and bone meal. It has been fertilized.

It was taken indoors from the garden centre. This was a month or more ago.

It is in a South window under bright plant lights. It is kept moist. It was allowed to dry between watering.

The leaves have yellowed and dropped off. There are some new buds.

I have not had success in the past with the dipladenia. What can I do to prevent it from dying?

Thanks,

Derrick Keene

Answer
Derrick,

Your plant needs to be kept pretty dry during the winter monhs giving it minimal watering  in the winter months.  I fpund the folowing care info on a German web site;   
Care Dipladenia  
 
SPRING:
Hibernation: Your Dipladenia is still inside, but temperatures are already rising in March, so you should slowly start giving the plant a little more water.
Habitat: In May you can put your Dipladenia in a sunny, reasonably sheltered spot on the terrace, the balcony or in the conservatory. But it is advisable that you take the Dipladenia inside at night if there is night frost.
Watering: Now that the Dipladenia is outside, the need for water will increase, especially in sunny weather. The pot ball must be kept nice and humid from now on. During spring and summer it is advisable to place this plant on a dish. If you ensure that the dish is full of water, the plant will always have plenty of water at its disposal and you will not have to water it every day. The dish should be occasionally removed during long periods of rain, so that excess water can drain off. If your plant grows an extremely long shoot, it is advisable to cut this back to its original length as soon as possible. Once the plant has flowered it is best to cut it back, as this ensures another magnificent show of flowers several weeks later.

SUMMER:
Watering: Throughout the summer season, the Dipladenia needs watering almost every day. Make sure excess water is allowed to flow freely from the pot and keep adding fertiliser for fourteen days. If you are using slowly released compost, you may add a second helping of compost to the pot or the soil in July.

AUTUMN:
Watering: In autumn, the need for water, especially from October onwards, strongly depends on the weather conditions. If it is warm and sunny, you may water the plant several times a week, but if it is cold and rainy, be very careful not to overdo it. Make the drainage hole at the bottom of the flower pot free from roots by poking in it with a pen or twig approximately 15 cm deep. After September you will have to stop adding fertiliser, else the Dipladenia will enter the winter season growing too fast.
Hibernation: If you live in an area where night frost may occur in early autumn, you need not be afraid that the Dipladenia will immediately die, because they are very good at surviving night frosts of minus 1 to minus 2 degrees Celsius. It is not until very late in autumn, when temperatures often stay below 5 to 6 degrees Celsius during the day as well, that it becomes time to take the Dipladenia inside. Place the Dipladenia in a cool, light spot. Temperatures between 0 and 12 degrees are best.

WINTER:
Watering: In this period you should water the Dipladenia very modestly, but absolutely make sure you do not let it dry up. It is not necessary to add fertiliser in this season.
Trimming: It is advisable to cut back shrub-shaped plants to about 30% of their total size, and plants on a stem to about 30% of their total spherical size. If you wish to trim the Dipladenia, it is best to do so in February.

If you have more questions write again. GTood luck.

Darlene