Flowering Bulb Size

July 14, 2008

Category: General

Download PDF

Hi every One
This is my first posting so here goes
This is a question for experienced exhibitors.Am I right in thinking; assuming a bulb has a Flower in it and it has only one nose and all other things being equal the larger the bulb the bigger Flower it will produce.
Ivor Clark

2 responses to “Flowering Bulb Size”

  1. Michael Berrigan says:


    I have to separate greenhouse growing and outside growing here.  In the greenhouse I will make the same statement, but the exception is that if I have grown all of the bulbs under the same conditions the larger rounds will produce the larger flowers.  I don’t grow all of my bulbs under the same conditions and in the greenhouse bulb increase is much lower than  that found outside.

    I plant my bulbs typically in size order and have found that the biggest and best flowers are in the middle of the planting.       I have found that the flowers also grow on the plant about 50% from first opening.

    I have attached a file representing a clump of Trevithian that I recently dug and cleaned.  The daffodils were down for many years.  I have sorted the bulbs into three size ranges.  Large bulbs probably double noses,  Large rounds probably single noses and smaller rounds.  As I look at the basal plates I see that the bulbs of the larger two sets to have about the same sized basal plates.  Since the first set is probably sharing its roots between two flowers, I would expect the strongest flowers to be from the middle row.  


    Bulb size has to do with available water where the plant was grown.  If one could sample each bulb and find the sugar or starch content that will vary even with the bulbs grown in the same area.  Having a goodly supply of energy to get going in the spring is only one step in the flowering cycle.  Having large healthy plants with adequate energy to flower is the goal.  I would estimate that in the greenhouse most of the energy is from the bulb.  Outside, most of the energy in flowering is from the plant.   I have found one thing that correlates to the best flower size and that is root mass.  

    Look at the basal plate.  The more roots, the more water, the more water the bigger the plant and the larger the flower.  Compare the basal plates of the plants.   The larger plates on the single noses will produce the biggest flowers.

    I would like to know if others have had different experiences.

    Michael R Berrigan
    Advanced Development Specialist
    Central Research Process Laboratory
    218-2B-03 3M Center
    Maplewood, MN 55144-1000
    651 736-9865

  2. Clay Higgins says:

    That is a nice picture of bulbs!!!  I’d like to have permission to copy that picture and use it in a presentation I’m doing later this year to a Master Gardener group in October.

    Clay Higgins