Vancouver, since 1937

Maximizing Blooms on your Sprays for the Late Show

The blooming dates of late sprays can be manipulated by restricting the hours of daylight for three and a half weeks at specific times.

Each Late Spray cultivar has a "response time” which is the number of days between the onset of “short” days and the optimum blooms:

Cultivar Response Time
Rynoon family 66 - 67 days
Ryflash 73 - 74 days
Romark 73 - 74 days
Ryski family 70 - 71 days
Rosescene 70 - 71 days
Robeam 73 - 74 days

Our Late Show in 2009 is on Oct 30/31 and Nov 1 so in order to force the blooms to occur on these dates we have to count back from these days the "response time" listed above for each cultivar, to arrive at the date for starting to restrict the hours of daylight.  This restriction of light must be for 14½ hours and must be continued daily for 3½ weeks.

For example: For the Ryski family a 70-71 day response time brings us to 20th August so on this date we blackout the plant for 14 hours daily {say 6pm to 8am} for 3½ weeks.  

Some growers construct a frame covered with heavy black plastic, while others wheel the plants into a blacked out shed or garage. At the end of this period the buds should be well formed and spaced right up the stem.

Of course you can take a chance and grow the plants straight up in a one gallon pot.  You may be lucky and produce blooms for the show but the blackout technique will increase your chances for more blue ribbons.

Bernie Milne

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