Re: A small collection: 2015 and beyond
Posted: Mon May 08, 2023 2:45 pm
That ariocarpus seems to have grown a whole lot!
On-line Guide to the positive identification of Members of the Cactus Family
https://www.cactiguide.com/forum/
Indeed! I moved the fissuratus from a terracotta pot to a glazed ceramic pot in 2015 -- diameter of the 2 pots is about the same, so this gives you some perspective on its growth going from 10/27/13 to 10/23/22:
Awesome and awesomer -- check out the view from today:
jerrytheplater wrote: ↑Wed Feb 15, 2023 4:12 am Steve
Thanks for the reminder about SDK1's posts. I did read them when they were posted and responded but did not follow up on Mike's book. I will see if I can borrow a copy from the library. I just went back and read the whole "When Cactus Turn Yellow" thread where MikeinOz gives his rationale for his ratio. SDK1 also went into plant tissue analysis. This is making more sense to me.
In the chart Mike gave, converting the tissue analysis to a elemental NPK ratio, you get for leaves: 1-0.26-1.66. For flowers you get: 1-0.17-1.62. In the Cholla stem analysis you get the following N:P ratios: 1:0.067 to 1:0.125. That is some pretty good evidence for lower P in fertilizers since plant tissues don't show high P levels compared to N and K.
MikeinOz said: "too much P can interfere with trace element uptake especially iron and it can reduce flowering. Too much K is very rare and usually not an issue."
So, now to see what "too much P" is. Maybe its in the book Mike supplied. When is iron uptake impaired?
Going by the NPK ratio set with N as a constant of 1, the Dyna-Gro 7-7-7's P at 0.44 was too high, but not high enough to cause serious long-term problems -- yet. Based on my observations so far, I've found that some species are more tolerant of the higher P than others. However, that tolerance lasts only so long, and for growers who dismiss the importance of keeping the P in their ferts down to a more acceptable level, they'll find that their cacti won't grow as well as they did in the past.MikeInOz wrote: ↑Wed Feb 15, 2023 5:22 amJerry, given that Phalaenopsis orchids are probably the most studied ornamental greenhouse crop, there is a lot of literature on their fertilization out there. Google scholar is the place to start reading. Too much P can lead to reduced growth, reduced flowering and interference with trace element uptake as well as outright toxicity if the dose is over the top....jerrytheplater wrote: ↑Tue Feb 14, 2023 4:46 am
I'd like to see some references that show what the effects of over feeding with P causes. Do you happen to know of any? I need to go over those articles I posted up last week. Might be something in there.
Before Mike joined the forum's fertilizer discussions in August 2020, I made a bad assumption about what the "ideal" NPK balance should be for cacti and succulents. And of course I was repeating misinformation I got from people who didn't know what they were talking about. Once I got some really good learning from him, I was surprised to find out that cacti and succulents share commonalities with nonxeric plants in terms of the actual balances that produce optimal growth. From there I came up with a basic "rule of thumb" -- P lower than N, K higher than both. Fine as far as it goes, but this doesn't tell us much without plugging N, P, and K numbers into the rule. Jerry, you and I already know this, so the following is for the benefit of members who may be new to the investigation of ferts...jerrytheplater wrote: ↑Tue Jul 18, 2023 2:18 pm Hey Steve, since you are quoting a lot of what I wrote, I'll post here, but maybe I should back in your thread.
I did see a graph of corn production in one of Mike's references (I think) which showed that increased P over what is termed "sufficient" in the literature, did not impact corn yields in any way up or down. It only led to wasted application of extra P and maybe more runoff of P. That is for the grass plant Corn, Zea mays.
I did see a mention of High P giving reduced blossoms in African Violets. Turns out it was lower light levels that had a much greater effect on blossoms than P levels. Increasing light levels increased bloom production.
He wasn't specific about the kind of reduced growth we're talking about, although I have a feeling that too much P in relation to N and K inhibits uptake of both nutrients, thus reducing root and stem growth. As I said in my previous post, this isn't just about flowering. Proof in the pudding:
That's a nice problem to have! If light levels do have an impact on flower production for African violets, I wonder if this would apply to cacti too. There may be too many variables to say for sure, but all I can tell you is that a good number of my cacti are producing more flowers now than they did when I was using the Dyna-Gro 7-7-7. More importantly, I'm seeing improved stem growth in many.jerrytheplater wrote: ↑Tue Jul 18, 2023 2:18 pmI did make up a modified fertilizer for my violets that converts Dyna-Gro Bloom 3-5.2-5.0 to 13.1-5.2-22.2 (1.0-0.4-1.7) in elemental terms. NH4:NO3 is 3.1:10.0 in the modified mix. Bloom is 0.7:2.3.
This conversion reduced the P levels from equal to K to about 1/4 K. Now it will be up to me to give a subjective idea of the results. But, I just did a major repotting of all of my violets to reduce long necks which involved decapitating the plants and re-rooting the top part. I took leaf cuttings of all as insurance. Now I have too many violets!
Steve Johnson wrote: ↑Tue Jul 04, 2023 10:09 pm The 4th came just a little bit early, so here are the doings from yesterday...
- Back row left to right -- Mammillaria guelzowiana, Gymnocalycium stellatum (or ragonesei?), Turbinicarpus jauernigii, Eriosyce napina glabrescens, and G. stenopleurum.
- In front of the Gymno (yeah, I think it's ragonesei) and T. jauernigii, we have a couple of Turb polaskiis -- one from the California Cactus Center and the other from CoronaCactus Nursery.
A few observations worthy of note:
- Front row left to right -- Coryphantha hesteri, Copiapoa hypogaea, C. tenuissima, and C. laui.
- I got the Mamm guelzowiana from Miles' To Go in July 2013. After 9 years of too much P in the Dyna-Gro 7-7-7, the plant decided to stop flowering last year. With the reduced P in my new fertilizer regimen, the flowers are back.
- Just like it's been with my Mamm theresae, the Turb polaskiis are blooming more now than they were in previous years. Yep, that's the reduced P.
- I got the E. glabrescens from CoronaCactus in July 2013, and the plant grew not at all with the 7-7-7. But when I supplemented it with Potassium sulfate and TPS Cal-Mag last year, the glabrescens finally started growing. Reduced P in the new fert regimen is giving us this:
Yes, my friends -- that's a bud! If it goes from bud to bloom, I'll try to get it on camera.
What I didn't realize at the time was that some species of cacti can be remarkably sensitive to NPK imbalance and nutrient deficiencies, the deficiencies being K, Ca, Mg, and S. With the imbalance and deficiencies corrected, the glabrescens is the "difficult" cactus that has shown the most significant improvement in a relatively short period of time. The polaskiis were "difficult" too, but not anymore, although it took about 2 years to get there. A few more examples coming up in the 2023 end-of-summer review.
Next we have Sulcorebutia rauschii:
The collection gets its first deep watering of the year with rainwater and nothing more. This year it was April 20 -- a little later than I would like, but not bad. Should've been water and fertilizer every two weeks after that, but the weather had other ideas. First feeding with water was on May 14. Then a touch of winter came back, and I didn't dare water again until things warmed back up in mid-June. The rauschii looks a bit nutrient-starved, although with regular water and fert on the summertime schedule, it'll green up nicely by the end of August. In the meantime, we can see something nice now -- active growth points indicated by off-white "belly button lint" on top plus 2 more buds about to bloom. And believe it or not, what you're seeing here started out in 2011:
4th of July fireworks tonight, but here's some fireworks we can see in the daytime:
Combine beautiful plant form and drop-dead gorgeous flowers -- IMO Mamm guelzowiana is the best of the genus.