REPLY: [pbs] Deeper planting bulbs
Mon, 17 Nov 2003 12:35:02 PST
Hello ~

> . . .the expert I consulted also recommended deep planting, in part because 
> the deeper the cooler, and in part because the deeper, the better the root 
> system and the sturdier the stem which, especially with lilies, tends to be a 
> weak point.  I am sure you've seen lilies splayed out on the ground with 
> their over heavy blooms just weighing down the poor 
> stems.  Supposedly planting bulbs deeper is a way to counter this 
> phenomenon.

Whether the stem of a given lily will stand stiffly upright with its 
inflorescence ( within consideration ) is not necessarily influenced so much by 
planting depth as it is by genetics.
The stems of the trumpet and Aurelian lilies of Division VI are notorious for 
not being able to stand on their own when in bloom without being staked 
(almost irrespective of planting depth).  In many cases, this is because they 
descend from Lilium henryi, a species with a weak stem or from one of the trumpet 
species with weak stems.  Trumpet lilies with a closer affinity to Lilium 
regale, on the other hand, are rather more able to stand on their own.  Many of the 
4n forms of these lily hybrids ( Division VI ) tend to have very strong, 
sturdy stems that will support the heavy inflorescence.  One will occasionally 
find some stem weakness in the Asiatic hybrids, but it is not common, as these 
hybrids will hold the inflorescence on a stiffly upright stem and descend from 
species where this is a dominant trait.

Jane and the others are certainly right, however, on the need for deep 
planting ( often as much as 7-8" of soil over the tip of the bulb ) as many lilies 
produce an abundance of roots from the underground portion of their stems.  
These roots serve to nourish the plant during growth and last only one season.  
Roots produced from the basal plate are much fewer in number, tend to be larger 
and heavier, are perennial in nature and serve to anchor the plant and absorb 
water.  When planting lilies, it is important to remember that they revel in 
a loose, organic soil that drains well but holds some moisture.  Many lilies, 
after blooming, do appreciate somewhat drier conditions.

There are some species that do not produce stem roots, Lilium martagon is 
often said to be one.  In my experience, this is not wholly true as a stem will 
sometimes produce a few.  I understand that this species, being native to light 
woodland conditions, is not exposed to heavy winds and, thus, does not need 
to be firmly anchored to the soil, as would a lily native to windy grasslands.

Dave Karnstedt
Cascade Daffodils
Silverton, OR USA

More information about the pbs mailing list