CHRYSANTHEMUM 




CUTTING S§S 
Continuous re a Chrysanthemums 
Since the advent of day-length and temperature control we have seen chrysanthemum cut flowers on 
the markets every month since 1946, thanks to our never-tiring research workers in various federal and 
state institutions. Season has been eliminated and the flowering time can be accurately controlled. 

-Daylength Control 
It has been known that the days are short enough for bud formation around September 20. This will 
vary somewhat depending upon your location in the States. To prevent flower buds from forming 
it is desirable to lengthen the day with additional light starting August 10. When one is using black 
cloth to reduce the length of the day the treatment can be discontinued September 20. 
Similarly in the spring the days are too long for further bud formation starting April 15. To prevent 
bud formation light the plants until April 20. If you want bud formation start shading March 15, or a 
little earlier if you are in the extreme southern states. 
Lighting 
The use of 100 watt lamps with reflectors spaced at six foot intervals, three feet above the plants, is 
sufficient light to prohibit bud formation. The light intensity must be 10 foot candles to prevent bud set. 
Several schools of thought exist on the time to start the additional light. One group prefers to light 
from midnight on while the other suggests that lights be turned on from about | hour after sundown. 
The number of hours to operate the lights is as follows: 
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septomberand “April 226 ones oats 2 hours 
Betopervoned Martens. 2 et Samat 3 hours 
November and February .............. 4 hours 
December and January ............... 5 hours 
Yoder Brothers have found that they could overcome poor spray formation by reducting the hours of 
lighting to one-third during the last third of the lighting period. That is, if the lighting period is 60 
days, the last one-third or the last 20 days would receive only one-third of the light normally given 
in that particular month. This will open up the sprays that normally are clubbed together. 
Shading 
Use a good durable Black Cloth which when applied will reduce the light intensity to 2 foot candles 
or less. More light intensity than this will result in delayed flowering and unevenness of bloom. 
The cloth should be applied at 5 P.M. and removed at 8 A.M. Continue covering each evening on 
pompons until the latest buds show color and most of the flowers are well developed. For large flower- 
ing varieties shading can be discontinued after all flowering buds have attained the diameter of 
approximately one-half inch. 
Be sure that covering is complete on all benches shaded, as any leaks in light will cause uneven spots 
in the bench at blooming time. 
Black cloth should be applied each evening although missing one night a week will give fair results 
but delayed flowering results when cloth is not applied each evening. 
Temperature Control 
For bud formation a minimum temperature of 60-65 degrees should be maintained. During the 
period of elongation or where bud formation is not wanted a night temperature near 60 degrees is 
ideal. When black cloth is started raise the night temperature to 60 degrees until color shows, and 
then it can be lowered. 
When growing a single bench of pompons in a cool house, it has been a problem how to increase the 
temperature necessary for bud set. A simple method is when applying black cloth allow the cloth to 
drop to the floor on each side of the bench. Turn on the heat lines under that bench and you will find 
that a 60 to 65 degree temperature can be maintained. 
Timing 
Rooted cuttings previously grown under additional light should be planted directly into the permanent 
location and pinched 21 days later. A soft pinch should be made. The period of elongation or the pe- 
riod which must have additional light will vary with the planting date. October planted cuttings will 
require a longer period to attain their desired height as compared with February planted cuttings. 
Therefore, we have added a schedule of continuous flowering of chrysanthemums. In this schedule you 
will find the date of planting, the date of pinch, which in all cases is 21 days after planting. The date 
the lights should be off as well as the shading date are found in this schedule. Remember to apply ad- 
eS ditional light from the day you plant until the respective date given under the heading Lights Off. 
