Orientation of bulbs
Jane McGary (Fri, 18 Oct 2013 12:01:12 PDT)

In the ongoing discussion of websites, Rodger wrote

You can be puzzled by this even if you are not a "raw newbie [novice,
newcomer]." When I was distributing bulbs I sometimes added a note on
the paper packet about the planting orientation. This is especially
true if you are growing bulbs from seed and potting on or planting
out the small, young bulbs, corms, or tubers. The other day I had a
number of one-year-old tubers of Arisaema candidissimum to plant in
the garden. I noticed that the roots came from the upper half of the
tuber and extended horizontally. I knew that the top of an aroid
tuber, at least those I usually grow, has a little protuberance or
"topknot" from which the above-ground parts of the plant will arise,
but in these little seedlings it can be hard to spot. In another
example, in the Liliorhiza section of Fritillaria (the western
American species, basically) the orientation of the young bulbs is
identified by a little "barb" or "hook" at the base, which is the
beginning of the second scale. And Cyclamen tubers of difference
species produce their roots from different parts of the storage
organ, and need to be planted at various depths depending on whether
or not they make a "neck." Certain Anemone tubers or rhizomes can be
even more difficult to interpret, and I have sometimes given up and
planted them sideways.

It is likely, however, that even if a bulb is planted sideways or
upside down, whether by a raw or an experienced gardener, it will
figure things out for itself. Very small bulbs are more tolerant of
this than large ones, so if you harvest a handful of tiny crocus
cormlets or a mass of first-year Fritillaria bulbs (which look like
little seed pearls), you can safely sprinkle them into a large pot
without puzzling out which side is up, and they will grow just fine.
Indeed, bulbous plants that produce masses of small offsets have
probably evolved this as a response to scattering by bulb predators;
a few of the tiny offsets are likely not to be found by the animal
and will remain in the nicely disturbed soil to carry on. In the
garden some of these heavily propagating species can turn into weeds
thanks to the gardener's assiduous weeding and other soil disturbance.

Jane McGary
Portland, Oregon, USA