Deeper planting bulbs
Mon, 17 Nov 2003 12:08:55 PST
In a message dated 16-Nov-03 4:41:53 PM Pacific Standard Time, writes:

> . . . planting bulbs deeper than "normal" discouraged bulbs from increasing 
> by side bulblets, and consequently gave larger flowers and continuing 
> flowering in subsequent
> years. In this case large flowered tulip hybrids were the example. The 
> commentary I think said "deeper planting, equals cooler bulbs, larger flowers, 
> longer bulb life," though presumably less bulb increase. Is this "cooler bulbs 
> point" a valid argument for bulbs like tulips, or indeed bulbs in general? 
> e.g. some reticulate irises which split up much
> more readily than tulips in my experience.

Hello all ~

In the commercial growing of daffodils ( Narcissus ), primarily the 4n 
hybrids, a "rule of thumb" is that shallower planting can contribute to more rapid 
increase.  In a business based on the selling of dry bulbs, this can be an 
important consideration!  On the other hand, planting a daffodil somewhat deeper ( 
5-7" of soil over the tip of the bulb ) than would be considered normal ( 
2-4" of soil over the tip of the bulb ) does, indeed, contribute to a slowed rate 
of multiplication.  The reason is simple.  It takes more energy to grow from 
a depth than it does to just poke above the surface to reach the light.  With 
less total energy available, multiplication ( a function of stored energy ) is 
retarded.  In this case, it's an important consideration when planting 
daffodils in the landscape where the intention is to keep them for a longer time 
before being forced to dig and separate them to improve flowering that tapers off 
as the bulbs increase and become crowded.

Tunicate bulbs ( generally ) produce an unbranched mass of roots from the 
basal plate -- an important consideration to bear in mind.  To insure long term 
success in landscape plantings, one has to loosen the soil to a depth of at 
least 18" to accommodate this trait.  It is also helpful to work in some moderate 
analysis fertilizer at that depth some time before planting begins.  Also, 
tunicate bulbs appreciate substantial moisture during their period of growth.  
Daffodils can handle at least an inch of water per week -- assuming the soil is 
friable enough for the excess to drain away.  They also respond better when 
kept dryish during Summer dormancy.

I would agree with the suggestions that have been made with respect to 
planting depth for seed of this type ( round, hard, black seed ).  I generally plant 
my daffodil seed at least an inch to an inch and a half deep in the 
indigenous soil in full sun and find this works just fine.  Although I've not always 
been able to follow the advice about planting the seed as soon as it is falls 
from the capsule, it is probably wise to do so.  When fresh, the seed is plump 
and shiny black.  As it dries in preparation for dormancy, it shrinks and 
becomes matte black.  The dormancy inhibitors formed during this process have to be 
washed away by rainfall before the seed will sprout.  In other words, planted 
fresh in June in this climate one will often see the little spears of growth 
in late Fall.  Planted in Spring ( seed harvested the previous June ), the 
seed will not germinate until the following Spring.  I know -- been there, done 

Dave Karnstedt
Cascade Daffodils
Silverton, Oregon  USA  97281-0237
Cool Mediterranean climate -- wet Winters, hot and dry Summers; USDA Zone 7-8


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