A. belladonna blooming project, and watering

Travis O enoster@hotmail.com
Sat, 13 Jun 2015 21:23:39 PDT
Good points, Mary Sue. But I think the ground temp may be more variable than the ambient air temps depending on the amount and timing of sunlight at key times of the year.

I've observed many individuals of species of bulbs native to Rogue River bloom relatively early in hotter, drier sites that receive sunlight quicker at the start of the year, and conversely later blooming individuals in sites that receive direct sun later in the year. Our somewhat northerly latitude means we have areas completely shaded during winter's whole duration (Northern exposure), and they are slower to get sunlight as the year progresses. Where the sun hits earlier (SE exposure) it triggers growth earlier than in shadier sites (NW exposure), the ground warming/thawing sooner in the case of the former and remaining colder or even frozen in the case of the latter.

For example, Erythronium hendersonii individuals in hot dry sites with a southern exposure that get sun for most of the year including winter tend to flower first, the individuals in shady sites with northern exposures that tend to stay frozen in winter and get no winter sun flower later.

So I wonder how A. belladonna responds to "full sun" sites with southern or northern exposures, if there would be a difference in flowering time. Depending on the latitude, one may receive more hours of sunlight in a year than another, affecting ground temps, but not necessarily ambient air temps.

Travis Owen
Rogue River, OR


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