Humidity problems

Trouble shoot problems you are having with your cactus.
Post Reply
User avatar
CosmicSerpent33
Posts: 41
Joined: Tue Nov 15, 2022 10:10 am
Location: North Island, New Zealand - Zone 10b

Humidity problems

Post by CosmicSerpent33 »

Hi everyone.

While checking over my cacti today I noticed what appears to be humidity blisters hidden on the back side (facing away from sun) of my Pachanoi.
These blisters and oedema have been a constant ever since I started collecting this summer
I tend to water my trichocereus more often than my other varieties given the amount of rainfall these guys can handle in their native habitat, but I am starting to think watering every 2 weeks is too much, even in the intense heat NZ has been getting. I use a moisture meter to check the soil is bone dry throughout the entire pot before watering, and currently use a mix of 20-30 percent cacti mix, 70-80 percent pumice. Soil dries out within a day or two in good weather. Humidity has been very high, like usual.

These raised spots are rock solid.
324623510_5789553514433301_2631238487467784151_n.jpg
324623510_5789553514433301_2631238487467784151_n.jpg (85.88 KiB) Viewed 639 times
North Island, New Zealand - Zone 10b
Average annual humidity: 80%
Average Annual precip: 1206mm/48.48''
User avatar
ohugal
Posts: 409
Joined: Sun Aug 18, 2019 10:45 am

Re: Humidity problems

Post by ohugal »

Looks more like scale in my opinion.
Location
Antwerp, Belgium
temperate, maritime climate with mild winters and cool summers
hardiness zone 8a
User avatar
Tom in Tucson
Posts: 426
Joined: Sun Jan 02, 2022 4:12 pm
Location: NW Tucson AZ area

Re: Humidity problems

Post by Tom in Tucson »

ohugal wrote: Mon Jan 09, 2023 3:53 pm Looks more like scale in my opinion.
I'll second that
User avatar
Steve Johnson
Posts: 4514
Joined: Thu Nov 03, 2011 4:44 am
Location: Los Angeles, CA (Zone 10b)

Re: Humidity problems

Post by Steve Johnson »

CosmicSerpent33 wrote: Mon Jan 09, 2023 7:05 amWhile checking over my cacti today I noticed what appears to be humidity blisters hidden on the back side (facing away from sun) of my Pachanoi.
Callused water blisters, and the black spots look like pockets of fungi. Typical for some columnar species growing in a humid climate. The humidity in my part of L.A. certainly rates for that, and I used to see what I just described on a Cephalocereus senilis I got 11 years ago. Not life-threatening, just unsightly. Apparently the plant acclimated well to the humidity because I haven't seen that problem in recent years. Unfortunately I don't have any experience with T. pachanoi, but I do have a lot of experience with fertilizers, so it's possible that your fert may be a bit of a problem. Give me the details on the fert you're using, how much you put in your watering solution, and how often you fertilize. Also, I need to know if your fert label is reporting elemental P and K or P2O5 and K2O. Since you live in New Zealand, I believe it'll be elemental P and K.
If you just want photos without all the blather, please visit my Flickr gallery.
My location: Los Angeles, CA (Zone 10b)
User avatar
CosmicSerpent33
Posts: 41
Joined: Tue Nov 15, 2022 10:10 am
Location: North Island, New Zealand - Zone 10b

Re: Humidity problems

Post by CosmicSerpent33 »

Well, I picked the callouses off thinking they were scale... I don't have any experience in dealing with scale but here is an image of what it looks like now:
324751202_641325254346979_2821613870236112246_n.jpg
324751202_641325254346979_2821613870236112246_n.jpg (68.65 KiB) Viewed 559 times
Now that I think of it, these lumps become raised, hard spots before any blackening or callousing happens. I can tell when one is coming because there will be a hard lump forming, but zero discoloration or scale.

@Steve Johnson Now that is interesting. I do know I was using the incorrect fertilizer at the start of the season, here is the details of that:
GUARENTEED ANALYSIS:
Total Nitrogen as Urea and organic 5%w/v
Total Phosphorus as water soluble 1%w/v
Total Potassium as phosphate and organic 4%w/v
Iron (Fe) as EDTA chelate 0.01
Copper (Cu) as Sulfate 0.005
Manganese (Mn) as sulfate 0.005
MAXIMUM Total P when diluted 0.02%w/w
Also containing fish emulsions and seaweed.
Mixed at a ratio of 40ml to 9L of water.

I only watered them with this a couple times at, before realizing the N to P ratio is way too high.
I have switched now to a proper Cacti and Succulent feed, however there is ZERO analysis of it on the bottle or their website, which is just ridiculous. Just claims 'Premium formulation designed to encourage optimum flowering and healthy plant growth. Developed with high potassium and low nitrogen for cacti and succulents' - Useless, I know.
I use the same ratio of 40ml into 9L, which is far diluted compared to what the bottle recommends (2 caps per 20cm pot).

I fertilize them every other watering (So approx every 3-4 weeks), but I also add liquid seaweed to it, at about 40ml per 9L. Bottle recommends 100ml per 10L. Could this be detrimental to them? I had seen it promotes healthy root growth, but that could have been wrong... I will also add, my soil is fertilized for up to 9 months, however given my organic to inorganic ratio I figured fertilizing them would be the right thing to do.
North Island, New Zealand - Zone 10b
Average annual humidity: 80%
Average Annual precip: 1206mm/48.48''
User avatar
CosmicSerpent33
Posts: 41
Joined: Tue Nov 15, 2022 10:10 am
Location: North Island, New Zealand - Zone 10b

Re: Humidity problems

Post by CosmicSerpent33 »

Steve Johnson wrote: Tue Jan 10, 2023 10:49 pm
CosmicSerpent33 wrote: Mon Jan 09, 2023 7:05 amWhile checking over my cacti today I noticed what appears to be humidity blisters hidden on the back side (facing away from sun) of my Pachanoi.
Callused water blisters, and the black spots look like pockets of fungi. Typical for some columnar species growing in a humid climate. The humidity in my part of L.A. certainly rates for that, and I used to see what I just described on a Cephalocereus senilis I got 11 years ago. Not life-threatening, just unsightly. Apparently the plant acclimated well to the humidity because I haven't seen that problem in recent years. Unfortunately I don't have any experience with T. pachanoi, but I do have a lot of experience with fertilizers, so it's possible that your fert may be a bit of a problem. Give me the details on the fert you're using, how much you put in your watering solution, and how often you fertilize. Also, I need to know if your fert label is reporting elemental P and K or P2O5 and K2O. Since you live in New Zealand, I believe it'll be elemental P and K.
Apologies, was supposed to quote you in my above reply.
North Island, New Zealand - Zone 10b
Average annual humidity: 80%
Average Annual precip: 1206mm/48.48''
User avatar
Steve Johnson
Posts: 4514
Joined: Thu Nov 03, 2011 4:44 am
Location: Los Angeles, CA (Zone 10b)

Re: Humidity problems

Post by Steve Johnson »

CosmicSerpent33 wrote: Wed Jan 11, 2023 2:24 amApologies, was supposed to quote you in my above reply.
No worries!

First of all, you have new water blisters forming. C. senilis isn't the only species I had that problem with, although there were a number of factors involved. My only "problem child" these days is an Astrophytum myriostigma that really doesn't like the humidity. I got it in June 2011, and here it is 10 years later:

Astrophytum_myriostigma10172021_01.JPG
Astrophytum_myriostigma10172021_01.JPG (159.76 KiB) Viewed 555 times
I'm showing you the good side -- the south-facing side is too ugly to show on the forum. Not sure if there's anything I can do to make the situation better.

Anyway -- in case you're not already aware of it, we have a professional horticulturalist with a deep knowledge of cacti on the forum. And since he lives in Australia, I believe you'll be able to buy the fertilizer he uses, so check this out:

viewtopic.php?p=382867#p382867

You'll see the guaranteed analysis here:

viewtopic.php?p=382937#p382937

My cacti have been doing remarkably well on a liquid fert regimen, although if I could get the Osmocote Cacti and Succulents formulation in the US, I would change over to it in a heartbeat. Unfortunately I can't, but I believe you can. Not sure if this would clear up your water blister problem -- however, I think you would do well with the Osmocote. Just something to think about.
If you just want photos without all the blather, please visit my Flickr gallery.
My location: Los Angeles, CA (Zone 10b)
Post Reply