Winter watering

Discuss repotting, soil, lighting, fertilizing, watering, etc. in this category.
LateBloomer
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Re: Winter watering

Post by LateBloomer »

jerrytheplater wrote: Sat May 21, 2022 1:10 am John was a founding member of the Connecticut Cactus and Succulent Society. Their website has some of his Powerpoint slide shows he'd present on Winter Hardy Cacti. Worth taking a look at. https://www.ctcactussociety.org/john-spain-slide-shows
Thanks for the link.
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greenknight
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Re: Winter watering

Post by greenknight »

Cacti are adapted to a yearly dry, semi-dormant period, but the length of it will vary in different climates. They set flower buds during the dormant season, and many species adapted to temperate climates need a cold dormant period to do that - in a tropical climate they'll bloom poorly or not at all. Trying to get flowers is a major reason for withholding water, in addition to avoiding etiolation and root rot.

Cacti do not produce anti-freeze - their sap just becomes a more concentrated solution when they're dehydrated, lowering its freezing point and reducing the formation of ice crystals. Their cells also lose turgor (become less rigid), so that any crystals that do form are less likely to rupture the cell walls. A water-fat cactus is much more vulnerable to freezing.
Spence :mrgreen:
LateBloomer
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Re: Winter watering

Post by LateBloomer »

greenknight wrote: Sat May 21, 2022 9:35 pm Cacti are adapted to a yearly dry, semi-dormant period, but the length of it will vary in different climates. They set flower buds during the dormant season, and many species adapted to temperate climates need a cold dormant period to do that - in a tropical climate they'll bloom poorly or not at all. Trying to get flowers is a major reason for withholding water, in addition to avoiding etiolation and root rot.

Cacti do not produce anti-freeze - their sap just becomes a more concentrated solution when they're dehydrated, lowering its freezing point and reducing the formation of ice crystals. Their cells also lose turgor (become less rigid), so that any crystals that do form are less likely to rupture the cell walls. A water-fat cactus is much more vulnerable to freezing.
Makes sense has anyone tested this that you know of? Any links would be awesome.

The paper I found is this I’ll try to research more.
https://rootgorelick.files.wordpress.co ... -32-44.pdf
LateBloomer
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Re: Winter watering

Post by LateBloomer »

https://www.academia.edu/56670422/Water ... mperatures

Decreased water content occurs regardless of water content in soil however from this paper and others suggest some deaths are from excess dehydration.
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jerrytheplater
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Re: Winter watering

Post by jerrytheplater »

LateBloomer wrote: Sun May 22, 2022 1:05 am
greenknight wrote: Sat May 21, 2022 9:35 pm Cacti are adapted to a yearly dry, semi-dormant period, but the length of it will vary in different climates. They set flower buds during the dormant season, and many species adapted to temperate climates need a cold dormant period to do that - in a tropical climate they'll bloom poorly or not at all. Trying to get flowers is a major reason for withholding water, in addition to avoiding etiolation and root rot.

Cacti do not produce anti-freeze - their sap just becomes a more concentrated solution when they're dehydrated, lowering its freezing point and reducing the formation of ice crystals. Their cells also lose turgor (become less rigid), so that any crystals that do form are less likely to rupture the cell walls. A water-fat cactus is much more vulnerable to freezing.
Makes sense has anyone tested this that you know of? Any links would be awesome.

The paper I found is this I’ll try to research more.
https://rootgorelick.files.wordpress.co ... -32-44.pdf
I just skimmed the paper and noticed it compares John Spain's results with theirs and notes the differences between their locations. They give a low bow to his superior horticultural skills on page 42. Very tactful.

I have saved this paper. It really gives some more ideas for growing outdoors. I tried a trough for a few plants years ago. Some of the plants I bought directly from John Spain, others from other vendors at the club show. Some did ok for about 5 years, but others did not. I ended up potting those cacti that survived. The trough is being used to grow Sempervivums and other succulents. Its on my deck all year long.
Jerry Smith
Bloomingdale, NJ
45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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7george
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Re: Winter watering

Post by 7george »

My soil is almost entirely mineral so I doubt there will be much issue with the soil drying within a few days. Do you keep your cacti completely dry during fall and winter months? Do you live in areas with hard freezes?
Yes, we do. My cacti or most are indoors in winter months, heated house. But for many of those I prefer dry winter (we have here ~ 6 months of winter). For others: grafted, small seedlings or tropical cacti I do occasional watering (once in two weeks, month, 2 months) depending on temperature and growth status.

Do you fuel your car if it stays parked for months?

If I lived in Brazil I'd water my cacti regularly year round maybe.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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MrXeric
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Re: Winter watering

Post by MrXeric »

Very interesting topic. I found this paper, https://www.ncbi.nlm.nih.gov/pmc/articl ... 040675.pdf, where three species of Opuntia were studied. They found that the most cold-tolerant species, O. humifusa, prevents freezing in part by having a lower water content, lower water mobility within the cells, higher concentration of simple sugars, and greater amount of mucilage. This seems to me that cacti, or at least Opuntia, really don't need water in the winter.

That's all good and well for plants that won't be getting liquid water at subfreezing temperatures anyway. But what about plants above freezing? As you said, it does rain over the winter in habitat, but is the water any use to the plants? Unfortunately, I haven't been out in habitat as much as I would like, but I did stop off the side of the road to Las Vegas last December and took a short walk out into the Mojave Desert.

This was at around 11am and it was 36F/2C, according to my car thermometer. It had rained the night before and the ground was thoroughly soaked.
Image

Dormant (not dead!) Cylindropuntia ramosissima
Image

Joshua Tree (Yucca brevifolia) looking pretty good. Not sure how these look when dormant?
Image

These next pictures were taken 2 days later at round 2pm, temperature was colder at 32F/0C. It had rained again, the night before.

Cylindropuntia echinocarpa, rather than C. bigelovii (I think). I'm actually not sure if this was dead or dormant. I don't grow these much. :)
Image
close up
Image

This one was dead, Opuntia basilaris, but notice the soil: all sand and gravel!
Image
I did see another O. basilaris on the walk back, but my hands were going too numb to take a pic (no gloves). It was alive, but dormant: sad, wrinkled pads.

At least from what I saw, it was very obvious that the plants here were dormant and would not respond to the rain during winter. It probably does get colder, and it does snow there: I had the unfortunate experience of being snowed in on back in December of 2019 and needing to sleep in my car since the roads were closed...

In my part of California, average nighty lows for winter are in the mid 40s (around 5C), but mid- to high 30s (0C) are not unusual. Day temps are in the 50s to 60s (10-20C). I grow everything but young seedlings outdoors and I keep my plants dry from November to March. I acquired a young Melocactus azureus over the winter that I did lightly water once a month or so, but I brought it in every night. Although I taper off watering, starting in October, most of my plants show obvious signs of going into dormancy in the fall: no new spine production and failure to respond to water (Tephrocactus are the first to wrinkle for me, despite light watering in the fall). As you can see, my winters are quite mild, but even then my plants go fully dormant. I used to water lightly once a month in the winter, since, despite living in a winter rain zone, days are typically sunny here, and warm days in the 70s (low 20s C) are not unusual. This year we even had several days nearing 90F (30C+). However, I never notice any plant responding to water and instead I would get some losses from rot. So it seems to me, that if my plants aren't growing and not responding to water, water over the winter is rather pointless and will risk rotting instead.
LateBloomer
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Re: Winter watering

Post by LateBloomer »

7george wrote: Sun May 22, 2022 2:49 am
My soil is almost entirely mineral so I doubt there will be much issue with the soil drying within a few days. Do you keep your cacti completely dry during fall and winter months? Do you live in areas with hard freezes?
Yes, we do. My cacti or most are indoors in winter months, heated house. But for many of those I prefer dry winter (we have here ~ 6 months of winter). For others: grafted, small seedlings or tropical cacti I do occasional watering (once in two weeks, month, 2 months) depending on temperature and growth status.

Do you fuel your car if it stays parked for months?

If I lived in Brazil I'd water my cacti regularly year round maybe.
I like the gas analogy but more appropriate would be your core in idle. Yes you don’t need to refuel as often BUT there is a consumption of resources and the larger the car the more you need to fuel. Idle f350 vs a fiat. Even then it would be relative cause I’d assume consumption is similar in proportion.

A cactus with unlimited access to water it would only drink what is needed it wouldn’t split. In cold weather the cactus would self regulate water uptake so in very cold weather it would only take enough to perform functions but the external cells wouldn’t store water and wouldn’t appear as plump. Second paper I shared shows that cactus releases excess water and this remains even with water present in soil

This is all an idea/experiment
LateBloomer
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Re: Winter watering

Post by LateBloomer »

MrXeric wrote: Sun May 22, 2022 8:23 am Very interesting topic. I found this paper, https://www.ncbi.nlm.nih.gov/pmc/articl ... 040675.pdf, where three species of Opuntia were studied. They found that the most cold-tolerant species, O. humifusa, prevents freezing in part by having a lower water content, lower water mobility within the cells, higher concentration of simple sugars, and greater amount of mucilage. This seems to me that cacti, or at least Opuntia, really don't need water in the winter.

That's all good and well for plants that won't be getting liquid water at subfreezing temperatures anyway. But what about plants above freezing? As you said, it does rain over the winter in habitat, but is the water any use to the plants? Unfortunately, I haven't been out in habitat as much as I would like, but I did stop off the side of the road to Las Vegas last December and took a short walk out into the Mojave Desert.

These next pictures were taken 2 days later at round 2pm, temperature was colder at 32F/0C. It had rained again, the
I did see another O. basilaris on the walk back, but my hands were going too numb to take a pic (no gloves). It was alive, but dormant: sad, wrinkled pads.

At least from what I saw, it was very obvious that the plants here were dormant and would not respond to the rain during winter. It probably does get colder, and it does snow there: I had the unfortunate experience of being snowed in on back in December of 2019 and needing to sleep in my car since the roads were closed...

In my part of California, average nighty lows for winter are in the mid 40s (around 5C), but mid- to high 30s (0C) are not unusual. Day temps are in the 50s to 60s (10-20C). I grow everything but young seedlings outdoors and I keep my plants dry from November to March. I acquired a young Melocactus azureus over the winter that I did lightly water once a month or so, but I brought it in every night. Although I taper off watering, starting in October, most of my plants show obvious signs of going into dormancy in the fall: no new spine production and failure to respond to water (Tephrocactus are the first to wrinkle for me, despite light watering in the fall). As you can see, my winters are quite mild, but even then my plants go fully dormant. I used to water lightly once a month in the winter, since, despite living in a winter rain zone, days are typically sunny here, and warm days in the 70s (low 20s C) are not unusual. This year we even had several days nearing 90F (30C+). However, I never notice any plant responding to water and instead I would get some losses from rot. So it seems to me, that if my plants aren't growing and not responding to water, water over the winter is rather pointless and will risk rotting instead.
Thanks for those habitat photos and info. The cold and light schedule will slow growth down growth but even without visible growth there are still other functions occurring. I have zero doubt that most if not all cacti can survive fall and winter without water and for those in climates that don’t have day temps over freezing.

This ideais obviously not for commercial growers but for those that try to imitate habitat as much as possible this is another aspect. Obviously people have been growing cacti with completely dry winters for a very long time and this idea may just increase risk of deaths from rot like you mentioned.
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MrXeric
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Re: Winter watering

Post by MrXeric »

LateBloomer wrote: Sun May 22, 2022 1:22 pm
Thanks for those habitat photos and info. The cold and light schedule will slow growth down growth but even without visible growth there are still other functions occurring. I have zero doubt that most if not all cacti can survive fall and winter without water and for those in climates that don’t have day temps over freezing.

This ideais obviously not for commercial growers but for those that try to imitate habitat as much as possible this is another aspect. Obviously people have been growing cacti with completely dry winters for a very long time and this idea may just increase risk of deaths from rot like you mentioned.
Certainly some functions are still active despite dormancy; the plants are still alive after all. But I wonder how much water, if any, the roots take up during dormancy? It would make an interesting experiment. I did a quick search and found no papers on this.
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mmcavall
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Re: Winter watering

Post by mmcavall »

What I observe here is that many plants become slow in winter but not completely dormant. Some new spines appear here and there. Others clearly stop growing and as Mr. Xeric says, Tephrocactus start very early in fall to not respond anymore and wrinkle.
I do water some of the plants (example Gymnos) while others I keep dry (example mature Mammillarias). Overall I'm satisfied with the results but I'm sure it is possible to better adjust waterings. For example resume waterings earlier (late winter, instead of spring) may would help them producing more flowers ? (I mean not induce flowering but gives energy to flower production...it is just something I think every year whem spring seems to never come).
LateBloomer
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Re: Winter watering

Post by LateBloomer »

The wrinkled cacti when temperatures start to cool doesn’t mean they are thirsty nor not drinking water but relocating water from external cells to more protected areas. Obviously if it’s sub freezing temps water uptake makes zero sense but when day temps even if only via uv radiation heat transfer from rocks water uptake should occur.

Soil makeup is most important here as inappropriate soil will lead to root rot.

Not to add too many factors but water evaporates at temps as low as freezing just at slower rate but with larger area like a Wide pot vs narrow. In nature the water will run much deeper than the roots so maybe this idea just isn’t practical in cultivation unless planted in ground?
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7george
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Re: Winter watering

Post by 7george »

A cactus with unlimited access to water it would only drink what is needed it wouldn’t split. In cold weather the cactus would self regulate water uptake so in very cold weather it would only take enough to perform functions but the external cells wouldn’t store water and wouldn’t appear as plump.
It will but the roots of many cacti are not adapted to exist long time in wet soil (when it's cold and no uptake of water occurs) so these can rot.

Regarding large cacti: these also need relatively less water because of two reasons. First, these have smaller ratio of surface to their volume so better keep water during dry months. Second, these are generally adult cacti with nominal size for the species so do not need to hurry with growing but producing more flowers and seeds. Seedlings have longer growing period, close to whole year so are active and thirsty longer time if not too cold.

I have lost enough many valuable specimens because of in-proper watering so I'm very cautious with winter watering of my cacti.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
LateBloomer
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Re: Winter watering

Post by LateBloomer »

That always sucks losing cacti… was it from watering/wet feet during cold weather? I’ve noticed in my experience I’ve lost very water tolerant cacti I can only assume due to large difference in cultivation from sellers greenhouse conditions to mine during late spring purchase.

Also this isn’t for organic heavy mixes but more mineral mixes. My trichocereus are still young but I grow in a mineral mix with organic soil. I’ll be watering these as well to test my idea. I’ll either have cacti that are fine or lose entire collection
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jerrytheplater
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Re: Winter watering

Post by jerrytheplater »

LateBloomer wrote: Tue May 24, 2022 11:48 am Also this isn’t for organic heavy mixes but more mineral mixes. My trichocereus are still young but I grow in a mineral mix with organic soil. I’ll be watering these as well to test my idea. I’ll either have cacti that are fine or lose entire collection
Hopefully you are testing on extras?
Jerry Smith
Bloomingdale, NJ
45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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