When to start watering; emerging leaves without rain; California N-S gradient

Peter Taggart petersirises@gmail.com
Tue, 29 Oct 2013 00:05:36 PDT
The moisture from dew can be very significant and adequate to start off
early rooting, especially with many sensitive dry area species.
I imagine that late Summer rainfall in almost all temperate climates is
normally accompanied by temperature fluctuations. Temperature fluctuations
may lead to dew if not rain

On Tue, Oct 29, 2013 at 1:20 AM, Gastil Gastil-Buhl

> Several PBS members from northern to southern coastal California and even
> the south of France have described when bulbs emerge in the fall relative
> to when the rain or irrigation begins. My garden is 300 miles south of
> Mike's and 100 miles north of Lee's but unlike the others, no significant
> rain has fallen yet this fall. (Rainfall amounts, in inches: June 0.10,
> July 0.06, August 0.00, September 0.02, October thru 27th 0.00; 0.01 inch
> is roughly 0.03 cm.) I will share my notes on which bulbs emerge without a
> moisture trigger.

>   Then later in October more and more had shoots (just the white
> cataphyll) and now even some have roots. This is without significant
> precipitation.

> Lately night temperatures have dipped below 50F / 10C and day temperatures
> are mostly in the 70's reaching 80F/27C less often. Now the soil is around
> 60F/15C at 4 to 6 inches depth. This hints Narcissus tazetta primarily
> responds to soil moisture but responds to cooling temperatures even without
> any moisture, other than air humidity or dew. Another generalization I feel
> confident making is that with moisture the roots emerge around the same
> time as the shoots but in absence of moisture the shoot precedes the roots.

 you will find this pattern repeated with the bagged bulbs and should be
keeping them below 15 C
Peter (UK)

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