FLOWERING or “Is Bigger Better?”
(The Case for Bulb-zilla™ size grade)

We have been repeatedly asked if big bulbs have bigger flowers. This is definitely NOT the case

The real fact of the matter is that quantity of flowers is directly related to bulb size, in a very dramatic way.

Commercial bulb sizes are 10/12, 12/14, 14/16 and so on, measured in centimeters circumference. The circumference is the measurement around the bulb. Bulbs often get as large as 30 cm around, but these are not often seen in commerce. Tpically these monsters are in home gardens, having been in place a number of years, steadily gaining in size. There are various reasons why big bulbs are not found in commerce:

  1. They take too long to grow to this size to be profitable to grower.
  2. They are very expensive to ship.
  3. The commercial bulb industry caters to cut-flower growers who try to produce smaller, more easily utilized flower stems for florists.
  4. Some new varieties are not plentiful enough in commerce to have large stores of big bulbs yet.
  5. Commercial growers reserve big bulbs for propagation of new bulbs, because they yield bigger, more productive scales needed for greatest bulblet production.

Do you suppose that a 20 cm bulb is twice as big as a 10 cm bulb?
This is definitely NOT the case. Using geometric calculations for spherical objects, we list below the actual three-dimensional sizes of commercial sized bulbs , so you can more realistically compare size differences and relative flowering capability.

Circumference Volume (directly related to weight and flowering capability)
10 cm 16.83 cubic cm.
12 cm 29.17 cubic cm.
14 cm 46.43 cubic cm.
16 cm 69.42 cubic cm.
18 cm 98.97 cubic cm.
20 cm 135.91 cubic cm.
22 cm 179.50 cubic cm.
24 cm 233.38 cubic cm.
26 cm 297.08 cubic cm.
28 cm 371.43 cubic cm.
30 cm 457.25 cubic cm.

Thus it is concluded that a 20 cm bulb is over 8 times the size of a 10 cm bulb in practical terms. It is also 8 times heavier and produces 8 times as many flowers.

This is a valuable thing for gardeners to grasp because we actually do WANT more flowers from our bulbs, unlike the florists. We want the most flowers for our money!

Let’s suppose a 10 cm bulb costs $1.00 and a 20 cm bulb of the same variety costs $5.00. Which is the better buy? If you get 8 times more flowers and only have to pay 5 times more money, then you have a better value with the large bulb in this illustration. Our BULB-ZILLA™ grade bulbs, which are at least 24 cm in circumference would outperform the 10 cm bulbs by a factor of about 71 in theory, but would not cost 71 times more!. Shrewd consumers need to comprehend the actual value when making purchase decisions of this sort.

Other “pros” and “cons” for starting with large bulbs.


  • No waiting for showy results
  • Less waiting for bulbs to divide. Many are already double or triple-nose bulbs at this stage (which throw multiple stems right off the bat) and will be fully separate bulbs in another year, each of which will continue to gain in size and divide again. You’ll be able to share with friends and neigbors in no time at all!.
  • Taller, stronger stems
  • Great entry material for floral competitions, state fairs, more blue ribbons for amateur exhibitors.
  • Excellent source of large fleshy scales needed for bulb propagation. By taking only the outer scales you have propagation material and can still plant the original bulb and obtain sizable stems.


  • Stems may be too big and too thick for cut flower arrangements.
  • Big bulbs of certain varieties show a tendency for leaf scorch when day and night temperatures fluctuate widely, during heat waves, and especially under greenhouse growing conditions. Other varieties are quite immune to leaf scorch. (NOTE: We avoid the susceptible varieties when offering our Bulb-zilla™ stock.)
  • If you have to pay weight-based shipping, it can be prohibitively costly to obtain large bulbs. (NOTE: Our Bulb-zilla™ stock is priced with added weight factored in already. So all you do is figure shipping based on simple dollar amounts, just like our regular stock.