How to Grow a Mandevilla Indoors

Moving from Outdoors to Indoors

• 1

  Cut the plant back drastically to about 2 to 3 feet tall to prepare it for reduced light levels indoors. Unless you have a greenhouse, you will not have enough light to support the same amount of foliage that the plant had outdoors.

• 2

  Repot it to a larger pot or root-prune the existing root ball and replace it in the same pot. If it has been growing outdoors in the same container all summer, it is likely to be root-bound and needs some space for roots to expand. Mandevilla requires well-drained soil, so use an appropriate potting soil. Add additional perlite to increase drainage if the potting soil seems heavy.

• 3

  Check meticulously for bugs or egg masses on all parts of the leaves and stems. If any are found, use an appropriate insect control. For extra insurance, spray with horticultural oil as a preventative measure.

• 4

  Bring it indoors before nighttime temperatures drop below 50 degrees Fahrenheit. If possible, bring it in before the heating season starts so it begins to adjust to the lower humidity and light levels without also dealing with the stress from indoor heating.

Indoor Culture

• 5

  Give your Mandevilla a brightly lit location in front of a window or slider that does not get cold winter drafts. The more sun it has, the more likely it will not go dormant. Mandevilla appreciates a nearby plant grow light in addition to natural light.

• 6

  Water only after the top few inches of the soil is dry. Over-watering causes root rot and other problems.

• 7

  Create a humidity tray for the plant to sit on. A tray or saucer of pebbles just barely covered in water will create much-needed humidity for the Mandevilla as the water evaporates.

• 8

  Monitor the plant for pest outbreaks and apply insecticide if needed.

• 9

  Consider moving the plant to a cool, dark area to rest for the remainder of the winter if it begins to lose many leaves -- but not below 50 degrees Fahrenheit. Water minimally just to prevent the soil from becoming completely dry -- 1 or 2 cups of water a month, depending on the size of the pot.