Petunias are a quantitative long day plant for flowering so will bloom
faster when exposed to long days but will eventually bloom even under
short days. I grew petunias under short days by covering them with
blackcloth from about 5 PM to 8 AM daily. This delayed blooming but
greatly increased the number of lateral shoots, and hence flowers.
The cultivar choice is also important. Multiflora types have more, but
smaller, flowers than the grandiflora types. Also, don't crowd them
because lack of light inhibits lateral shoot development.
*********************************************************************
David R. Hershey
Snail mail: 6700 Belcrest Road #112, Hyattsville, MD 20782-1340
Adjunct Professor, Biology/Horticulture Dept.
Prince George's Community College, Largo, MD 20772-2199
Email: dh321 at pgstumail.pg.cc.md.us
*********************************************************************
On 30 May 1997, Hillary Grey Fleenor wrote:
> Hi! I am a lab aide for the freshman level botany labs at NAU. I was
> wondering if anyone could give me some advice on how to make petunia
> plants big and bushy with LOTS of flowers for a pollen tube germination
> experiment that we do. I would really appreciate the input. The plants
> are grown indoors in a greenhouse. Thanks so much.
> Hillary
>>