Are all cacti "long-day plants"?
Are all cacti "long-day plants"?
title pretty much sums it up. are all cacti clumped into this group?
Cacti grow when it is warm and wet. Relatively few of them are constrained by day length (or night length) to grow at particular times, but a few do have dormancies set by the calendar rather than the weather. Quite a few more flower only at particular times of year regardless of the actual growing conditions.
For most cacti warm and wet means summer, but for many it is spring and autumn (more or less), and for some winter is the rainy season. A few are from regions where rainfall is highly erratic and condensation is the principal source of moisture, winter is the best time for growth but again these species are not constrained by the calendar.
In cultivation, most of us are restricted to growing them in the summer, regardless of what they might do in habitat, and for most species this works just fine. Watch out for the few that insist on a summer dormant period.
For most cacti warm and wet means summer, but for many it is spring and autumn (more or less), and for some winter is the rainy season. A few are from regions where rainfall is highly erratic and condensation is the principal source of moisture, winter is the best time for growth but again these species are not constrained by the calendar.
In cultivation, most of us are restricted to growing them in the summer, regardless of what they might do in habitat, and for most species this works just fine. Watch out for the few that insist on a summer dormant period.
--ian
In habitat cacti are "opportunistic" growers ie when a "set of conditions" is considered as most favorable then the plants are triggered to grow. When this will happen is mostly directed by the characteristic of the species. The striking example are the so called "winter growers", the behaviour of Southern hemisphere species in the Northern hemisphere. Neoporteria is one of those. They do not grow and set buds in Fall because they want to grow in winter but because of the fall conditions up North here mimic their trigger conditions in their habitat. Unfortunately our winter follows and presents mostly harsh conditions so many plants come to a "stand still" and may (or may not) resume producing growth &/or flowering the next Spring if it is setting in fast enough. In their habitat their winter is exactly the good condition to run through their normal vegetation and reproductive cycle for the conditions they've been "programmed" to grow in.
The fact that we are obliged maybe to impose a strict winter rest may be very much contra indicated compared to a normal growth condition in habitat and it is imposed by local factors and because we have no better choice if we want to keep the plants alive trough that period.
I have been told by many people who visited habitat that some plants that come from the more moist pampa regions only have a very short "rest" (max. 2 months) when they are facing the "inapropriate season" and then resume growing to start a new full productive season. That seems to fit very well with the growing conditions commercial growers exploit in places like Tenriffa .. plants growing almost year round with no ill effects.
It also explains why many habitat explorers can claim they found not a single plant in one specific habitat at one given moment but find the place crowded with plants when they return to the same spot 3-4 years later ... the plants did not fall from the trees did they ?
FWIW & JMHO
The fact that we are obliged maybe to impose a strict winter rest may be very much contra indicated compared to a normal growth condition in habitat and it is imposed by local factors and because we have no better choice if we want to keep the plants alive trough that period.
I have been told by many people who visited habitat that some plants that come from the more moist pampa regions only have a very short "rest" (max. 2 months) when they are facing the "inapropriate season" and then resume growing to start a new full productive season. That seems to fit very well with the growing conditions commercial growers exploit in places like Tenriffa .. plants growing almost year round with no ill effects.
It also explains why many habitat explorers can claim they found not a single plant in one specific habitat at one given moment but find the place crowded with plants when they return to the same spot 3-4 years later ... the plants did not fall from the trees did they ?
FWIW & JMHO
Horum omnium fortissimi sunt Belgae.
when you say they are triggered by seasons are you saying its temperature, water or light? if light than the cacti you mention would reproduce due to photoperiodism. no? or is it the temps that do this to them?
you say in their range they flower in winter but up north (colder and shorter days) they flower sooner....this makes me think its either photoperiod or temps.
you say in their range they flower in winter but up north (colder and shorter days) they flower sooner....this makes me think its either photoperiod or temps.
The boolean operator for the parameters is not "or" but "and" .. the full set of parameters has to match a best fit, they have to balance each other to provide a situation that those plant might "sense" as an opportunistic ideal growth situation in light, temperature moisture and what more .. I can water my plants all I like in early Spring, if light and warmth are missing I will just kill them, same goes for other combinations with a missing condition ..Loph wrote:when you say they are triggered by seasons are you saying its temperature, water or light? if light than the cacti you mention would reproduce due to photoperiodism. no? or is it the temps that do this to them?
you say in their range they flower in winter but up north (colder and shorter days) they flower sooner....this makes me think its either photoperiod or temps.
I did not say that "winter growers" generally behave differently in habitat and here up North not at least what the triggers are concerned, I'm just saying that the Fall conditions here in the Northern hemisphere best mimic what the plants perceive as their "ideal" growing condition with this difference that up North here this condition is not lasting long enough due to a harsh winter which at their habitat latitudes may be more as a continuated Fall climate ..
Why do you insist on "unlinking" global growth parameters/triggers into individual situations of light or warmth or ...?
I know that cacti growers try to link succulent metabolism to what local conditions they observe in cultivation but IMHO it is about time to think the other way round and observe how well these plants are willing to adapt to what might be a harsh "mistreatment" compared to their original habitat conditions.
I know that with well controlled (commercial) equipment plants can be "programmed" (short day systems amongst others) to flower at a commercially interesting time (say "mother's day" or such) just to boost the sales. It is hardly something a serious succulents lover would want to do !
& BTW according to our winter dormancy I once asked one of our research Botanists what he thought to be the mechanism why many plants were not winter hardy here .. he suggested that because of the "opportunistic growth" that going into dormancy may be a very slow metabolic transition so the plant could build up energy as long as possible when conditions are favorable but OTOH coming out of dormancy could be a very short metabolic transition just for the very same reason and that is why an early awakening due to "instable" climatological conditions, that frequently appear in Jan-Feb-Mar here ie sudden warm+sunny+moist spells, plants may be pulled into a growing cycle too early but having no means of defending themselves against a fast changing climatological condition a few days later,just because of the above mechanism .. they cannot cope with the suddenly changed and unfavorable growth conditions ..
FWIW & JMHO
Horum omnium fortissimi sunt Belgae.
this thread is specifically about reproduction and flowering. When i was asking about the seasons i was referring to the fact that in their more southern home the season is winter. the same/similar conditions in your more northern location are in fall. because we are talking about shorter photo periods i am thinking maybe this has something to due with flower trigger in those plants? no?
many plants are triggered to flower because of light periods, or dark periods.
one reason i bring this up is because yes i do want to try and play with flowering times and such. secondly i am interested in trying to flower with various light techniques.
see this link. it is sort of what i am interested in. i am playing with other types of plants...but was curious if i could also do this with cacti.
see the part on photo period and their experiment.
http://users.rcn.com/jkimball.ma.ultran ... _to_flower
many plants are triggered to flower because of light periods, or dark periods.
one reason i bring this up is because yes i do want to try and play with flowering times and such. secondly i am interested in trying to flower with various light techniques.
see this link. it is sort of what i am interested in. i am playing with other types of plants...but was curious if i could also do this with cacti.
see the part on photo period and their experiment.
http://users.rcn.com/jkimball.ma.ultran ... _to_flower
Hi Loph- sorry I kind of misunderstood what you were wondering. It's clear now that you are asking about day length as a trigger or one trigger for flower production. It seems there are some cacti that have a very clearly defined flowering period that occurs in spite of little to no change in ambient temperatures. I'm thinking of Pediocactus simpsonii, for example, which flowers while still freezing in many parts of its range. Perhaps this is evidence of an adaptation to photoperiodism?
Maybe too some of the desert cacti that flower reliably the same week every summer, like clockwork, are responding to a particular photoperiod.
Interesting question.
peterb
Maybe too some of the desert cacti that flower reliably the same week every summer, like clockwork, are responding to a particular photoperiod.
Interesting question.
peterb
This is always difficult to untangle because our weather usually coincides with the daylength (despite 'unseasonal' blips!)peterb wrote:Maybe too some of the desert cacti that flower reliably the same week every summer, like clockwork, are responding to a particular photoperiod.
Loph's "playing" would clear this up; I'd be surprised if someone hadn't done this already but there's no harm in investigating it yourself.
right now i have some Lophophora sp., Aztekium, Astrophytum and a few other odd balls put inside where its darker (by a semi shaded window). the Aztekium has started flowering (but was budding when i put it in so I'll let it be for a while). the rest, which were flowering profusely before, have all halted and not one bud, flower or fruit has been seen since. this is not fair as the temperature has also dropped but feeding and watering has remained the same.
i was just curious what people know about this topic and cacti as i only have a few sp. to play with. or rather only a certain amount of space to play with
right now i am mostly playing with vines in the morning glory family and a few others bushes...so space is very low right now
i was just curious what people know about this topic and cacti as i only have a few sp. to play with. or rather only a certain amount of space to play with
right now i am mostly playing with vines in the morning glory family and a few others bushes...so space is very low right now
Photoperiodism for flowering has been clearly demonstrated in several cactus species. The best documented, no doubt because it is the most important commercial flowering cactus, are various "holiday" cacti. Although these are naturally found in or near the tropics, not the most obvious location for photoperiodic behaviour, they are also from environments with relatively little temperature and rainfall variation during the year. So perhaps day length is the most reliable indicator of season.
As Phil mentioned, it is difficult to untangle reactions to day length from other changes by casual observation. Several cacti which I observed to flower at particular times of the year regardless of temperature include Ariocarpus, Neoporteria (classic pink-flowered species), and Pediocactus. Suitable quantities of light and water are still required or there are no flowers at all.
Conversely, some species which might be though to react to the length of the day, actually show wide variation in flowering times depending on temperature and availability of water. Some spring-flowering Echinocereus and some winter-flowering Mammillarias do this. Day length may still be an important factor in the induction of buds, since my observations tend to show delayed flowering in some conditions.
Other species appear to be responding primarily to temperature and water and, for me at least, flower in summer. With suitable artificial light, regardless of day length) and heat they can also be made to flower in winter. Many Gymnocalyciums and Notocactus species seem to behave this way. Copiapoas also, although there seems to be considerable variation with different species preferring to flower at different times of the year even under identical conditions.
As Phil mentioned, it is difficult to untangle reactions to day length from other changes by casual observation. Several cacti which I observed to flower at particular times of the year regardless of temperature include Ariocarpus, Neoporteria (classic pink-flowered species), and Pediocactus. Suitable quantities of light and water are still required or there are no flowers at all.
Conversely, some species which might be though to react to the length of the day, actually show wide variation in flowering times depending on temperature and availability of water. Some spring-flowering Echinocereus and some winter-flowering Mammillarias do this. Day length may still be an important factor in the induction of buds, since my observations tend to show delayed flowering in some conditions.
Other species appear to be responding primarily to temperature and water and, for me at least, flower in summer. With suitable artificial light, regardless of day length) and heat they can also be made to flower in winter. Many Gymnocalyciums and Notocactus species seem to behave this way. Copiapoas also, although there seems to be considerable variation with different species preferring to flower at different times of the year even under identical conditions.
--ian
YMMV indeed
In the times that I was obliged to hibernate my plants is a "street level basement" under artificial lights two genera could not be kept under control. Copiapoa and Echinocereus started growing (and largely etiolating) every year, year after year, around February and Echinocereus was setting buds that never opened. I had to abandon growing these genera just because of this stubborn behaviour combined with my hibernation conditions
FWIW
In the times that I was obliged to hibernate my plants is a "street level basement" under artificial lights two genera could not be kept under control. Copiapoa and Echinocereus started growing (and largely etiolating) every year, year after year, around February and Echinocereus was setting buds that never opened. I had to abandon growing these genera just because of this stubborn behaviour combined with my hibernation conditions
FWIW
Horum omnium fortissimi sunt Belgae.
excellent thanks guys. one of my big interests is Hylocereus undulatus. it starts flowering in june/july to august/september (dragon fruit season here).
the temperature difference is not huge. the big differences are water (typhoon season is summer) and light. many get water year round...so unless flooding is a trigger i'm not sure its water. just playing with that feel free to comment.
there is a large difference in dark/light periods. winter is shorter days but because it is dry as a bone there is no clouds and the nights are darker (unless full moon). summer has longer days but it is generally cloud covered. so its still bright-ish and stays "light" throughout the night. i am *thinking* the lack of a true dark period could be a trigger...again just thinking out loud. As we all know they are a night flowering specie, so light does seem important for a flower trigger...but i am curious as to why they choose this season...every year reliably here.
the temperature difference is not huge. the big differences are water (typhoon season is summer) and light. many get water year round...so unless flooding is a trigger i'm not sure its water. just playing with that feel free to comment.
there is a large difference in dark/light periods. winter is shorter days but because it is dry as a bone there is no clouds and the nights are darker (unless full moon). summer has longer days but it is generally cloud covered. so its still bright-ish and stays "light" throughout the night. i am *thinking* the lack of a true dark period could be a trigger...again just thinking out loud. As we all know they are a night flowering specie, so light does seem important for a flower trigger...but i am curious as to why they choose this season...every year reliably here.