The latest arrival gets a repot (with 7/28 update)

[Steve Johnson]

Big rain in the forecast suggested that this weekend wouldn't be a good time to continue my Terracotta out, glazed ceramic in project. However, a nice weather window today opened up the opportunity to repot a cactus that really needs it...

I received a "welcome aboard" gift when I joined the Sunset Succulent Society in January, and here's what I selected from the donations table:



No way I was going to repot this lovely plant in winter, so I gave it occasional sips as one should do with Discocactus. I've been getting my Disco buenekeri and Melocactus matanzanus through this winter routine just fine -- the crystallophilus should be fine too, right? Well, I noticed a nasty black spot on the base about 2 weeks ago. Since spring is around the corner, now would be a good time to repot it and see what's going on underneath in the process:



Uh oh, necrosis. Not much in the way of roots either, and yellowish patches along the base are especially troubling. The grower lives in my general area, and unusually cold weather right after Christmas would've been enough to start the plant on a tailspin if he failed to keep it above 38 at night. I have a feeling this is what happened, and knowing how tricky Discos and Melos can be during wintertime, I don't think my latest acquisition will stand much of a chance for survival. But I'll try anyway.

Standard procedure whenever I get a potted cactus is -- toss out the grower's mix, clean the roots as thoroughly as possible, then soak them in 1% Hydrogen peroxide. But I went a little further this time by getting more of the plant down into the peroxide solution so the area affected by necrosis would also be soaked. After 15 minutes in the solution, I gently rinsed the crystallophilus in running water and let it dry. A few hours after that, repotting into fresh, dry mix:



As many of you already know, my mix of choice is a coarse pumice-DG aggregate. A few of my cacti need some soil in there as well, so the crystallophilus is now in an 80/20 mineral/soil mix. The buenekeri and Melo matanzanus love it, and hopefully the crystallophilus will respond to being in the same mix. With that said, it's a fair question to ask -- is the plant a goner already? I have a bad habit of giving up too easily sometimes, so I'll leave this as a rhetorical one. We'll come back and see what happens before the end of summer.

[gemhunter178]

Are the spots/the are around them mushy? My crystallophilus had that (probably from too much water in winter), I cut mine open and it was rotten to the core- yours doesn't look as bad though.

[Steve Johnson]

Are the spots/the are around them mushy?

That's the first thing I looked at when I un-potted the plant -- the necrotic patch and yellowing areas aren't mushy, so at least that was good. However, the general condition I'm experiencing now gives me a sense of deja vu about what happened with the Melo matanzanus I got in 2011 that eventually went to the great compost heap in the sky. If my crystallophilus goes in the same direction, it'll get more and more shriveled as the necrosis spreads, and I'll see that around the base of the plant. However, if it manages to regrow roots, I'd be thrilled. Unfortunately the roots of my 2011 matanzanus ended up looking as bad as what we're seeing now, hence why I'm not optimistic about a positive outcome here.

Well, my friends, I've been enjoying the D. buenekeri so much that I definitely want at least 1 other Disco species represented in the collection. James may have a nice horstii for me soon, although it'll depend on whether or not any of his survive the AZ winter in an unheated GH. And if the crystallophilus doesn't make it, I'll be prepared to find a suitable replacement should the need arise. The big Huntington show and sale at the end of June perhaps? I'm pretty sure that I'll know by then what the crystallophilus is telling us. Whether it's good news or bad, the Discocactus story will continue.

[jp29]

I feel your pain, Steve. I think that kind of cold environment damage is not unusual on "low altitude habitat " Discocactus and Melocactus (the vast majority of species) and highlights the need to grow these plants in a warm winter environment for safety sake. The only species of either genus that I have found able to reliably survive low winter temperatures are Discocactus placentiformis and Melocactus andinus both of which are sometimes found naturally growing in high altitude habitats that occasionally experience frost.

However, Steve, all may not be lost for you -- in the past I have salvaged plants of both genera with the same cold weather damage that you depict by re-locating them in a warm, dry, environment for the remaining winter months and with-holding water. That may work for you in this case living as you do in southern California.

Here is a mature Melocactus harlowii (Cuba) that recovered after such treatment. Two years on it is now fully recovered and flourishing.


Showing basal stem cold damage


Fully healed after above treatment

PS: I am afraid the Discocactus horstii that I had put aside for you, Steve, succumbed to low temperatures in one of Dan Bach's unheated greenhouses (how ironic!). I may have to send you a grafted plant.

[jp29]

Here is a pic of two Discocactus placentiformis (syn. D. alteolens sensu lato) plants taken last summer -- they were growing outside on the ground at my Townhpme and survived two successive winter nights of 15°F (-9.4°C) several years ago. They have both survived several frosty winter nights since and flourish today exhibiting only the stem rib scars shown in the pics.





This species has been reported found growing on high plateaus in the state of Minas Gerais, Brazil, where winter frosts sometimes occur.

[Steve Johnson]

However, Steve, all may not be lost for you -- in the past I have salvaged plants of both genera with the same cold weather damage that you depict by re-locating them in a warm, dry, environment for the remaining winter months and with-holding water. That may work for you in this case living as you do in southern California.

Thanks for your wise counsel, James! What you notice on your Melo harlowii is precisely what I hope to see if the Disco crystallophilus recovers -- necrotic tissue leading to a callous. I'll be keeping a close eye on this, and if that hope comes to pass, I'll know the plant is on its way back to good health and growth.

What a shame about the hortsii! Craig Fry has been doing some great work with the species, and if I remember correctly, he said that degrafting and re-rooting them isn't as difficult as one may think. (I'm sure the climatic similarity between my part of L.A. and his in Costa Mesa helps!) Before you go to the trouble of sending me a grafted horstii, I'll PM Craig and find out if he'll have a re-rooted one available soon. If he does, I'll give C and D Plants a spot of trade. If not, I'll take you up on your offer. Such being the case, I really do appreciate your kindness!

Now back to the crystallophilus. My portable GH is continuing to do an excellent job of keeping the daytime highs up above the lower 70s on the plant bench. However, overnight lows are still in the 40s for the most part, so I'm not ready to declare an early spring just yet. My thought was to give the plant a sip next weekend, then continuing every week or two until the overnight lows are consistently above 50. That's what I'm doing with the buenekeri and Melo matanzanus. When those lows start reaching the above-50 benchmark (could be in a few weeeks!), the sips will give way to soaks. I have the routine down pat with all of my healthy cacti, but what about the crystallophilus? Any further thoughts would be appreciated!

[jp29]

.......... What you notice on your Melo harlowii is precisely what I hope to see if the Disco crystallophilus recovers -- necrotic tissue leading to a callous. I'll be keeping a close eye on this, and if that hope comes to pass, I'll know the plant is on its way back to good health and growth ..........

Exactly, Steve. It hasn't always worked for me though -- sometimes they succumb despite your very best heroic efforts.

.......... What a shame about the hortsii! Craig Fry has been doing some great work with the species, and if I remember correctly, he said that degrafting and re-rooting them isn't as difficult as one may think. (I'm sure the climatic similarity between my part of L.A. and his in Costa Mesa helps!) Before you go to the trouble of sending me a grafted horstii, I'll PM Craig and find out if he'll have a re-rooted one available soon. If he does, I'll give C and D Plants a spot of trade. If not, I'll take you up on your offer. Such being the case, I really do appreciate your kindness!..........

I agree with Craig Fry -- he is an excellent experienced grower. We will leave things as you suggest for the time being.

.......... Now back to the crystallophilus. My portable GH is continuing to do an excellent job of keeping the daytime highs up above the lower 70s on the plant bench. However, overnight lows are still in the 40s for the most part, so I'm not ready to declare an early spring just yet. My thought was to give the plant a sip next weekend, then continuing every week or two until the overnight lows are consistently above 50. That's what I'm doing with the buenekeri and Melo matanzanus. When those lows start reaching the above-50 benchmark (could be in a few weeeks!), the sips will give way to soaks. I have the routine down pat with all of my healthy cacti, but what about the crystallophilus? Any further thoughts would be appreciated!

It seems you have got things well under control, Steve -- growing Disco's and Melo's can be fun, huh?

[Steve Johnson]

Since we're well into summer now, it's time for an update as we see how my Disco crystallophilus is doing these days. On March 21, followed by the view 4 months later:



The necrotic tissue is slowly being replaced by a callus, which we can take as a good sign. Furthermore, the crystallophilus appears to be taking up water rather nicely, suggesting that it was able to rebuild a decently healthy root system -- another good sign. The only thing I'm not seeing is detectable progress in cephalium growth yet. However, I don't think there's any reason to be concerned given what the plant had to go through in the recovery process. In my part of L.A., August is the hottest month of the year, and with plenty of summer left, I'm cautiously optimistic about seeing new cephalium growth before the growing season is done. A flower would be nice too, although I honestly wouldn't expect one this summer. If the crystallophilus begins its spring with a healthy, well-established set of roots, then hopefully the plant will bless me with its first flower next summer.

[C And D]

I just cut those Discocactus horstii heads off my grafted plant last week.
I wanted them to get as big as possible before I took the knife to them, though I wouldn't consider them very big, about 3/4" across.
They will take a month or so to root.

[Steve Johnson]

I just cut those Discocactus horstii heads off my grafted plant last week.
I wanted them to get as big as possible before I took the knife to them, though I wouldn't consider them very big, about 3/4" across.
They will take a month or so to root.

If you have one you'd like to sell after it's rooted, please send me a PM.