CHRYSANTHEMUMS in ABERDEEN

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2001 Paul Barlow


Feeding Chrysanthemums

My growing programme is  based on the ideas of Dr Barrie Machin. Dr Machin has kindly agreed to the inclusion of my interpretation of his ideas and methods.

This page is closely related to the Soil Analysis page. To begin with I will try to give an explanation for the following diagram.

machin.gif (14392 bytes)

The optimum levels for chrysanthemum growth is considered to be 200ppm Nitrogen and 200ppm Potash for all stages.

The start point for this approach is to have the following parts per million present in the growing medium at planting out:
Nitrogen  - 175 ppm
Potash     - 200 ppm.

The feeding program is based on liquid feeding with a solution containing 275ppm Nitrogen and 100 ppm Potash. This will gradually bring up the nitrogen content in the growing medium to the optimum 200ppm, and will maintain the potash level. Of course it is necessary to understand how to calculate the strength of liquid feeds. There is a separate page that explains this: Calculating Liquid Feeds.

Typically, with other methods, all feeding stops at the point where the buds begin to show colour. This approach advocates feeding continuously through bud and bloom development. The diagram shows both nitrogen and potash levels declining when feeding stops. This is referred to as the area of 'lost potential' of bloom size and quality.

There are risks, but ' nothing ventured - nothing gained'!

The following sections summarise Dr Machin's ideas.


MACHIN'S RULES
for feeding Chrysanthemums

  • CHRYSANTHS DO BEST ON A DIET OF 1N:1K IN ALL STAGES OF GROWTH
  • 200ppm N & K IN THE GROWING MEDIUM IS BEST FOR CHRYSANTHS
  • DEVIATION FROM 1:1 CAN BE 3:2 IN GROWTH STAGES AND 2:3 IN BLOOM DEVELOPMENT, PROVIDED SUFFICIENT N IS AVAILABLE
  • NITROGEN IS LEACHED 3 TIMES FASTER THAN POTASH
  • CHRYSANTHS DIVERT ALL NUTRITION INTO DEVELOPING BLOOMS FROM 4 - 6 WEEKS BEFORE FLOWERING - BLOOM FEEDING STARTS NOW!
  • FEED RATES TO MAINTAIN 200ppm N AND 200ppm K CAN BE UP TO 275ppm N AND 100ppm K.

KEEPING THINGS IN PERSPECTIVE

  • 275 N ppm IS EQUIVALENT TO 1 PART IN 3636 PARTS
  • LET'S SAY A PLANT IS FED 20 TIMES AT 1 LITRE OVER THE SEASON
  • THIS MEANS 20 LITRES = 20,000mls @ 1:3636 = 5.5 mls N
  • THIS IS FRACTIONALLY OVER 1 TEASPOONFUL NITROGEN
  • BUT THIS IS REDUCED BY LEACHING AND THE PLANTS INABILITY TO CONSUME ALL THAT WE APPLY
  • IS THIS REALLY EXCESSIVE?

MACHIN'S WARNINGS

  • 275 N AND 100 K IS THE FEED RATE ON HIS SOIL. OTHERS WILL BE DIFFERENT
  • ON A CLAY SOIL 200 N AND 100 K MAY BE MORE APPROPRIATE
  • HIGH N IN FINAL STAGES WILL INCREASE SIZE BUT INCREASE RISK OF DAMPING SO FUNGI AND HUMIDITY CONTROL IS ESSENTIAL

WHO DARES WINS!

Based on Barrie Machin's article in the National Chrysanthemum Society Year Book 1995


If you would like further information or wish to comment on this publication please send your e-mail to: paul.barlow@chrysanthemums.info

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Last updated on 16 December, 2001