Anyone have an interest in O. polyacatha?

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penstemon
Title: Member
Joined: 2010-06-24

Quote:

It must be due to a physiological reaction to the length of day more than to the onset of cold weather.   

Predictive dormancy is used by plants (generally) adapted to the local climate to enter the dormant period, and this is usually based on day length. Technically, it's based on night length, but nobody ever goes around saying "night length".
Consequential dormancy is another strategy, when a plant is triggered into dormancy by a cold snap, or by cold experienced prior to the time it would ordinarily undergo predictive dormancy.
So you can have two plants of the same species that are equally cold hardy, but the one from North Dakota will go dormant before the one from southern New Mexico.
In fact you can see this happen. Both the catalpa down the street and the desert willow in my front yard start losing their leaves at the same time, but the chitalpa next door gets its leaves frozen. So do desert willows from places like Arizona. (There are about 8 of them here, from all over the southwest.)
My desert willow is from a famous plant south of Santa Fe, has endured everything Denver's weather can throw at it for over 20 years, but the chitalpa's desert willow half is apparently from a more southerly accession and doesn't go into dormancy as early. (Tashkent, where the chitalpa was bred, is not particularly cold, so they would have had no reason to look for a specially cold-hardy form of desert willow.)

Bob

Bob

extreme western edge of Denver, Colorado; elevation 1705.6 meters, average annual precipitation 30cm; refuses to look at thermometer if it threatens to go below -17C

Weiser
Title: Member
Joined: 2009-12-04

Nold wrote:

Predictive dormancy is used by plants (generally) adapted to the local climate to enter the dormant period, and this is usually based on day length. Technically, it's based on night length, but nobody ever goes around saying "night length".
Consequential dormancy is another strategy, when a plant is triggered into dormancy by a cold snap, or by cold experienced prior to the time it would ordinarily undergo predictive dormancy.
So you can have two plants of the same species that are equally cold hardy, but the one from North Dakota will go dormant before the one from southern New Mexico.
In fact you can see this happen. Both the catalpa down the street and the desert willow in my front yard start losing their leaves at the same time, but the chitalpa next door gets its leaves frozen. So do desert willows from places like Arizona. (There are about 8 of them here, from all over the southwest.)
My desert willow is from a famous plant south of Santa Fe, has endured everything Denver's weather can throw at it for over 20 years, but the chitalpa's desert willow half is apparently from a more southerly accession and doesn't go into dormancy as early. (Tashkent, where the chitalpa was bred, is not particularly cold, so they would have had no reason to look for a specially cold-hardy form of desert willow.)

Bob

I have seen this happen in my garden with Opuntias collected in North Dakota as compared to those collected in Arizona. It doesn't matter to the North Dakota plants, if it is 80f and damp or 40f and dry, every year they will go dormant and shrivel right on cue.

From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV  zone 6-7
http://www.flickr.com/photos/sierrarainshadow/
John P Weiser

penstemon
Title: Member
Joined: 2010-06-24

Quote:

I have seen this happen in my garden with Opuntias collected in North Dakota as compared to those collected in Arizona. It doesn't matter to the North Dakota plants, if it is 80f and damp or 40f and dry, every year they will go dormant and shrivel right on cue. 

Yep. And for some cactus, the gymnocalcyium with the tissue damage for example, if it had had time to lose enough moisture before getting its rear end (literally, that was the back side of the cactus) frozen, it might have made it through much colder temperatures later on.
This happened with an enormous Agave havardiana x scabra cross that I had planted in the front garden to startle visitors during the 2002 NARGS tours. A 70 degree drop in temperature in November turned the thing to complete mush within a day.
(Scabra isn't really hardy here but I thought I'd give it another try.)

Bob

Bob

extreme western edge of Denver, Colorado; elevation 1705.6 meters, average annual precipitation 30cm; refuses to look at thermometer if it threatens to go below -17C

Weiser
Title: Member
Joined: 2009-12-04

Bob
I meant to comment on your last photo. Did you drug that poor droopy Imbricata? It is extremely limp!! ;)

We all know how O. polyacantha can hybridize with other Opuntias here are a few examples I grow.

                                 'Claude Arno'   O. polyacantha x O. fragilis
                                           
                                               
                               Possible hybrid   O. macrorhiza  x  O. polyacantha

                                               

                                 Devils Tower, Wyoming   O. polyacantha x O. fragilis

                                               

From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV  zone 6-7
http://www.flickr.com/photos/sierrarainshadow/
John P Weiser

penstemon
Title: Member
Joined: 2010-06-24

I finally got 'Claude Arno' last summer, at the DBG plant sale, after looking for it for years. 'Claude Arno' was the reason why Mary Ann called me all those years ago, she was looking for it too, having been friends with Barr .....

The trouble with opuntias, and it is big trouble, is the Cactus-Sucking Bug. I'm sure it has real name, but they attack pads and puncture them and then you have all these light green circles all over your cactus pads.
Dr. Bronner's takes care of them, but I decided it wasn't worth the trouble.
At least we don't have the giant cactus beetle here.

Bob

Bob

extreme western edge of Denver, Colorado; elevation 1705.6 meters, average annual precipitation 30cm; refuses to look at thermometer if it threatens to go below -17C

Weiser
Title: Member
Joined: 2009-12-04

Chelinidea vittiger aequoris is the one a friend was plagued with a few years ago. He said he had not noticed them until he saw the nymphs scury for cover one day on a stroll through his garden. It didn't take long to get rid of them but he had to treat the whole garden to do it.

Here are some links to information on the "little offenders". They even have mugshots. >:(

http://www.gatescss.org/Pests/Opuntia%20Bug%20Cactus%20Bug%20Opuntia%20B...

http://colinlmiller.com/wildlife/hemiptera/hemiptera_pricklypear.htm

From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV  zone 6-7
http://www.flickr.com/photos/sierrarainshadow/
John P Weiser

Andy71
Title: Guest
Joined: 2012-01-26

Weiser wrote:

Of all the cylindropuntias, C. imbricata is the hardiest, but in your climate it would be very marginal. I wish you luck in finding a clone that will grow in your area. The good thing is, it only takes a small branch cutting to get a start going.

I've heard that C. davisii is one of the cold hardiest of all the chollas. I know of one in a Massachusetts garden that grows well without a mark on it, so it can handle some moisture too. C. whipplei is very hardy too though the hardier forms tend to stay lower and spread. 

Connecticut - zone 6 (humid) - 54" of rain/year

Andy71
Title: Guest
Joined: 2012-01-26

Weiser wrote:

Named Hybrids and selections abound. Here is a small parade of a few that have flowered for me.

Opuntia polyacantha Claude Barr hybrid I do not know the original name of this one. It has been passed from gardener to gardener to gardener etc.... for years and came to me unnamed. It looks like a possible hybrid with O. aurea. If anyone knows the name I'd like to know.

                                                 [attachthumb=1]

                                                   

You gave me two pads of this one John and I would say it is very likely a polyacantha x aurea hybrid or possibly even polyacantha x pinkavae. Its doing ok here so far.

Connecticut - zone 6 (humid) - 54" of rain/year

RickR
Title: Moderator
Joined: 2009-09-21

Welcome to the forum, Andy!

I am always keeping an eye out for the hardiest cholla, and one that might stand heavy snowfall better.  You just never know...

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

Andy71
Title: Guest
Joined: 2012-01-26

Thanks Rick!

Here's a pic of that C. davisii growing in Northhampton, Mass. It may have been flattened a bit from the October snowstorm.

Connecticut - zone 6 (humid) - 54" of rain/year

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