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-====== Notes for BCSS on heating, lighting, etc. ======
-for the Southampton BCSS meeting on Tuesday 7th May 2024
-====== https://rwhite.uk ======
-===== Heating =====
-Carl Garnham's article is aimed mainly at seed raising, i.e. heating small spaces rather than an entire greenhouse:
-  * hysteresis
-  * "many thermostats on the market leave a very great deal to be desired"
-  * "Many seeds need a diurnal variation in temperature to germinate."
-  * Heating pads and soil warming cables
-Full article, including links to references and equipment:  [[https://sabg.uk/_media/newsletter:sabgnews49.pdf|Thoughts on heating]] by Carl Garnham, SABG Newsletter no. 49 (August 2023)
-===== Lighting =====
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-Growers of South African bulbs probably get more worried about light levels than succulent growers, because the former plants tend to grow in winter.
-. Always keep greenhouse glass, inside and out, as
-scrupulously clean as is possible.
-. If any particular plant/species is associated with
-shade in habitat, think carefully about possible
-lighting levels habitat v. inside a UK greenhouse.
-. Within a UK greenhouse, in winter, with clean glass
-and bubble insulation in place, light levels and
-insolation will be a small fraction (10-20%?) of the
-level in winter, in habitat, in RSA.
-. Remove bubble-wrap insulation when not required,
-although it may be needed during the winter, the
-time of least natural daylight (insolation) in the UK.
-. Providing truly significant supplementary levels of
-growth-promoting lighting (PAR) beyond sunlight in
-a UK greenhouse is neither simple, nor cheap, more
-so if using anything but commercial horticultural
-designs and very much so in winter.
-. Stimulation of flowering/extending photoperiod does
-not require major levels of lighting.
-. Experiment, with winter photoperiod, lamps,
-reflectors and positioning of lamps, and perhaps
-colour of lighting – there is no data out there for any
-plant that we choose to grow, so far as I have been
-able to find. (Just a prompt – is the glaucous colour
-of some plants seen in nature, which is seldom seen
-in many plants in European cultivation, triggered by
-total insolation, or by high levels of just one colour?
-It would be comparatively easy to massively boost a
-narrow band of colour if that was all that the LED
-produced (assuming that LEDs are available that
-produce that colour), which is what commercial
-horticultural lighting does.)
-. If anyone experiments, to come closest to
-understanding what is going on, a measurement
-device is needed; you cannot trust your eyes (a
-consequence of the amazing biological engineering
-that eyes represent)
-Full article, including links to references and equipment:
-[[https://sabg.uk/_media/newsletter:sabgnews50.pdf|My first tinkering with artificial lighting
-for plant growth]] by Carl Garnham, SABG Newsletter no. 50 (March 2024)
-===== Composts etc. =====
-In an earlier SABG Newsletter, there is an article on cat litter as a potting medium.
-FIXME Add a link to the article.