Orientation of bulbs

Jane McGary janemcgary@earthlink.net
Fri, 18 Oct 2013 12:01:12 PDT
In the ongoing discussion of websites, Rodger wrote
>Perhaps I should
>add that the PBS mailing list is (imo) for enthusiasts with some experience,
>not raw newbies who don't know which end of a bulb goes on the bottom.

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

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