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I am getting more interested in horticulture and want to know if there is any way of identifying which plants wake up/go dormant with day lengths and which ones react to the temperature drops and rises. Thanks.



Yea, there is, but you'd need to study horticulture or botany, or at least read some good textbooks on the subject. Some plants are what is known as 'short day' plants, others respond to both temperature and light, hardy plants respond to lessening daylight hours in late summer by making internal preparations for winter. The type of information you mention is often utilized by professional growers to manipulate flowering times and so on. The RHS, I think, still does part time courses for amateurs lasting a year or so where this kind of thing might be covered - it certainly is part of the syllabus for the M.Hort, professional course. Not that I remember much about it now, to be fair, that's not the sort of information I ever needed much down the years in the sort of horticultural work I did, and you know what they say - use it or lose it!

13 Jan, 2019


There's so much variety & so many variables that there are no hard & fast rules that I know of.
The learning is part of the fun though?☺

13 Jan, 2019


There's an article here on photoperiodism, in case its of interest - photoperiodism is about how plants respond to light, or, in fact, dark - they measure the length of darkness rather than light... but this article is just a taster really

13 Jan, 2019


just to add to the photo-periodism, there are plants that respond to red light or far red light and it depends on which frequency is the final stimulus as to whether flowering is initiated.

its used to be on the OCR Biology A level syllabus. used to drive the kids mad.

13 Jan, 2019


I looked at the link given by Bamboo then went on to look further. I found 'You are a serious gardener if …..' How well the writer describes me and a few other members of Goy.

14 Jan, 2019


Funny, Seaburngirl - sounds like its no longer on the syllabus?

The thing about gardening is, it seems simple, just stick a plant in and watch it grow, but if you want to know how,when and why, its much more complex and more interesting than that. Its always been a source of amazement and wonder to me, when you look at the detail of how a living organism functions, that it actually functions at all, because so many of the systems are quite delicate and inter related. I include humans and plants in that...

14 Jan, 2019


things come and go on a syllabus Bamboo, replaced by genetic engineering, gene therapy etc. then with the next rewrite that can be back in and others out. the role of the kidney and liver often play the hokey-cokey too :o). Different exam boards also have different content. All have very little plant biology though biochemistry of photosynthesis is always in and I hated that part but the perk of being HOD meant I could give it to other staff to deliver. I am more an anatomy & physiology biologist rather than a biochemist. I certainly preferred anat & phys. That's why I love biology, looking down a microscope, dissection and direct observation.

14 Jan, 2019


I certainly don't recall much plant biology when I did science/biology exams at school... it was mostly human biology, or maybe I think that because that's the bit I really liked at the time! I do remember some tedious stuff about gas therms I think... I just focused on the human biology and lucky me, the exam proved to have a large percentage of those sort of questions or I'd have failed miserably...

14 Jan, 2019


Thanks for the replies/ I will follow up on the link. Not sure about the RHS course. I may check out distance learning.
The reason I asked in the first place is that I have a couple of dipladenias that I trimmed back in October so I could bring them indoors. They have had constant temperatures but have now started back into growth so it must be light levels rather than heat.

18 Jan, 2019


Hi, yes you're right, Dipladenia' start to develop buds, when they get 10 to 11 hours of daylight, Derek.

20 Jan, 2019

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