Light:

Grow in a sunny window.  The best exposure is south; the next best would be east or west.  To flower well, they need some direct sunlight.  They are light-sensitive, which means that the shortening day length of fall is what stimulates flowering.

Temperature:

Generally maintain a minimum temperature of 60 degrees, especially during the winter months when light is low.

Humidity:

Preferably 50% or higher; however, they will tolerate low levels with no harm.

Watering:

Bring soil to a state of visual dryness between waterings.  In clay pots under warm conditions, they can have a high demand for water and, thus, should be checked once a day for dryness.  Try to prevent them from wilting severely; however, a slight wilt shouldn’t hurt.

Fertilizer:

Fertilize with a soluble fertilizer, ½ tsp./gallon every two weeks or, if grown under high light, ½ tsp./gallon once a week.  They are rapid growers, so if growth becomes too excessive, reduce the amount of fertilizer given.

Pruning:

Over a growing season, they can become large vines that won’t fit well in the indoor growing space.  Pruning of the vining stems should be done after the blooming cycle is complete, usually in late spring.  At this time, they can be pruned severely, from which they quickly resprout.  Another pruning can be done only if needed in late summer; from there on, the vine should be allowed to grow until buds appear.

Thunbergias have the greatest susceptibility to spider mites.  Attention needs to be given to signs of infestation, which begin as small light spots the size of a pinprick appearing on the leaf.  They are small and are found on the undersides of the leaves.  A magnifier may be needed to see them.  Plants that have been summered outside often come in with residual populations.  Spray 2 applications, 1 week apart of pure Neem Oil diluted 1-1/2 teaspoons to the quart of water to which a dribble of dishwashing liquid is added, or a quart of 50% alcohol and water, to which a dribble of dishwashing liquid is added.  For the above, spray the entire plant in the cool of the day and repeat 15 minutes later.  Repeat the above in 4 days.

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