Ponkan tangerine trees are not a dwarf variety and actually grow larger fruits than most tangerine trees. Fortunately, even though they are not true dwarf trees, they are grown indoors like dwarf tree varieties. In fact, their are two types of Ponkan tangerine trees you can grow indoors. Either select a Ponkan tree that has been grafted onto a dwarf rootstock, or choose a regular-sized Ponkan tree and prune large and older branches after fruit production each year.
Place your Ponkan tangerine tree in the sunniest area of your home, such as in a sunroom, under a skylight or next to a sunny south-facing window. If your summers are frost-free, set your tree outdoors in the sun if possible. First, though, allow your tree time to acclimate to the outdoors by setting it in the shade for a couple hours per day, and then place it in an area that receives about six to eight hours of sunlight a day.
Keep the temperature between 55 and 75 degrees F and the relative humidity levels between 30 and 60 percent.
Water when the soil is dry to about 2 inches below the soil. Water your tree thoroughly and stop as soon as it begins to seep out of the drainage holes.
Pollinate your Ponkan tree with a soft paintbrush or cotton swab. Gently brush the stamens when the blooms are open.
Fertilize your tree every two to four weeks--except during the winter months--with a fertilizer labeled for citrus trees. These products are typically high in nitrogen. Follow the dosing, application and frequency directions on the label. If you use a granular fertilizer, water your tree after application. Slow down your fertilizing schedule if you notice yellowing leaves.
Keep an eye out for spider mites, scale, thrips and mealy bugs. If you notice these tiny insects or any damage, treat immediately with a pesticide labeled for citrus trees. If you're not sure which kind of insect you have, take a sample of the bug or a damaged fruit or leaf to your local nursery for correct identification.