Rex Begonia Culture for Commercial Growers

A.     Grow in lowered light levels.  Be sure that the first 2 weeks of growth are in low light situation.  800 to 1000 foot-candles is ideal.  After 2 weeks, grow on at 1200 to 1500 foot-candles.  In western Oregon, we grow in full light till April 1, then 50% shade till May 10, then 75% shade the rest of the summer.  Light levels higher than this will stunt the plant, even if you see no burn.  HID lights shorten crop time in winter.

B.      Plant into very porous potting media.  Rex Begonias have fine delicate roots.  They hate overwatering.  Let soil get on the dry side before watering, but don’t allow the plants to wilt.

C.      Don’t over fertilize.  Maintain an EC between 1.1 and 1.8 if possible.  We constant feed at 125 ppm except in darkest weather we increase to 150ppm nitrogen.  Something like a 20-10-20 is fine.  In winter we feed with a low ammonia fertilizer.  Coated fertilizer like Apex or Osmocoat can cause problems in hot weather.

D.      Don’t grow too cold.  Our varieties finish reasonably fast with a 62 degree F night temp with days slightly warmer in winter.  66 + degrees will decrease crop time; lower temperatures will increase crop time.  Temperature averaging seems to work well with rex begonias and can save energy.

Failure to meet any of these conditions could jeopardize your crop.  If these conditions can be met, you will find Rex Begonias an easy crop to grow.

Mealy bugs can be a common pest.  Good systemic s and IGR’s like Enstar have proven effective.  Beneficial insects like Cryptolaemus have proven to be very effective for us.

A preventative spray program for foliar diseases such as powdery mildew is recommended.

Timing depends on temperature, time of year, fertility etc.   This is our timing in Oregon in our conditions.

Timing:         4” pots                  1 plant per pot                  8 weeks

                     6” pots                  1-2 plants per pot            8-14 weeks

                     8” pots                  3-4 plants per pot            12-16 weeks

We grow our plants pot tight for half the crop then space the 6” at 10 X 10” or about 1.5 plants per square foot.  This will give you very good returns on your bench space.

Plantsmith begonias have been bred for easy, low cost production.  We select our varieties to have medium sized leaves, to finish fast at 62 F, to perform well year round, and to have flexible leaf petioles for shipping.  We think you will be pleased with the results.