SUITABLE COMPOST  +  GOOD TUBER  +  RIGHT CONDITIONS

and

DOING THE RIGHT THING AT THE RIGHT TIME

will give a

GOOD PLANT

that will produce

GOOD BLOOMS

Given good stock and compost, the right conditions and doing the right thing at the right time, correct WATERING is the single most important factor in
SUCCESSFUL BEGONIA GROWING.

---------------------------------------------------------------------------------------------

SUITABLE COMPOST.
   For many years now I have used only peat based composts,  the preference being for SCOTTS LEVINGTON PROFESSIONAL.  I use 50% F2 with 50% Irish Moss Peat for starting, M3 for potting on and final potting.  Once the buds are allowed to develop (about 3 weeks after final potting) I apply a top dressing again using M3.

GOOD TUBER.
   Like most things in life, if you want the best you have to pay for them.  Named varieties do not come cheap. The main nursery in the United Kingdom is BLACKMORE & LANGDON.  Expect to pay £10 - £20 for a dormant tuber.  New introductions are currently £30.  Do not be alarmed by the irregular shape, what you are receiving is a tuber grown from a cutting, this is because tuberous begonias do not grow true from seed.  New varieties are developed by hybridisation, hundreds are then grown from the resulting seed and any promising plants retained for further assessment the following year.  Once selected (possibly 4 -5  years after first flowering) stocks have to be built up and this can take several more years. All this adds up to extensive labour and expertise, hence the seemingly high prices.

    But good stock does not just mean buying expensive tubers it means looking after them correctly right through the year.  If you do they will last for several seasons and you can carry on increasing stock by taking cuttings from them each year.

RIGHT CONDITIONS.
   Large flowered tuberous double begonias do not make good house plants, growing to the full potential requires a greenhouse.  This will need heating in the early months then shading and plenty of ventilation as the season progresses. 
    What can be more difficult sometimes is trying to to maintain a suitable environment during the flowering season.  Very high temperatures make the buds blow open too quickly and flowers deteriorate prematurely whilst wet weather causes blooms to damp off around the edges.

DOING THE RIGHT THING AT THE RIGHT TIME.
   Understanding the needs of the plant as it develops.  Potting on at the right time, staking, disbudding, feeding and most important of all CORRECT WATERING.

GOOD PLANT.
   This is what we are aiming at!  A well grown plant of good stock is the building block for good blooms.  The foundation of a good plant is of course the root system.  By the time the first blooms are open the pot should be well full of roots, but not completely pot bound.  Until the plant is fully grown all buds must be removed, even the finest varieties will produce poor blooms from early buds.  As a general rule the plant should be 3 weeks in it's final pot before the buds are allowed to develop.