Help me save a cactus pup from a deceased mother plant

[NeilR25]

Hi. I'm new to the forum and this is my first post and I could use some helpful advice.

About 15 years ago I purchased a rooted cutting of a very large crested cactus that I was told was Pachycereus pringlei, though I do not know the actual species. Due to it's large size, it did not move with me and stayed at my parents house where I only see it every couple months. Long story short, after the recent heavy rains in Southern California, it became water logged and nobody noticed until it rotted from the inside and died. It had a single offset that fell off but appears mostly healthy.

The pup was about 22 inches long and had some mushy black rot on the surface of the wound around where it detached from the mother plant. It was not very deep but to be safe, I cut about 3 inches off the bottom until it appeared that no discoloration remained in the plant tissue. Using what I had on hand, I cleaned it with alcohol and dusted it with strong Hormex rooting powder. I set it aside to callus but less than 24 hours later the wound turned brown in spots. It still appears firm, though. Not sure if this is mold, fungus, or some kind of oxidation...

Any advice for success is appreciated. This is my prized cactus and I want to do anything I can to save it. Does it look healthy? Should I address it differently or simply leave it alone to callus? What are my next steps?

Also, can anyone identify the variety?

I am attaching a couple photos for reference.

Thanks,
Neil

[Tom in Tucson]

You've done a nearly perfect job of saving what's left of this cardon. I checked the ingredients in Hormex rooting powder, but could not find any fungicide properties. Some rooting powders also contain fungicide.

2 things I would do now are either dust the wound with sulfur or a fungicide, and place the cutting in a shady dry area. Check the wound periodically for fungus or roots.

Good luck.

[jerrytheplater]

Just remember that roots might take a few months to show up. Patience.

[NeilR25]

Thank you for the advice! I couldn't find any powdered antifungal sulfur but I did get some sulfur soil acidifier, which is like 30% sulfur. Dissolved some into a slurry, added a bit of liquid antifungal spray, and painted it on thin over the wound. Dried in about 5 minutes so hopefully will provide a layer of protection. Is it optimal to wait until roots start to form before planting or can I plant it in a well-draining cactus mix in a couple more weeks?

[jerrytheplater]

You could pot it in bone dry potting mix and hold the water till it roots. But if you leave it unpotted, you can see the little buds of the roots just starting to form.

[greenknight]

If you leave it on its side, you need to turn it regularly or it might send roots out the bottom side.

[NeilR25]

Update time, and it may not be great. I needed to get the cactus out of the way so a couple weeks ago I put it in a dry mix of pumice, coarse sand, lava rocks and soil and set it aside. Today I pulled it out to check on it and it is fairly soft with a black powdering spot in the middle. I was able to scrape some away with my finger and took the photo. The soil is bone dry, never watered. Should I start cutting more of the bottom away? Please help before its too late!

[NeilR25]

I scraped away a bit more of the soft black material and about 5-6 mm down it's yellow with the medium firm texture of a pear. Hoping for some insight here. In the meantime I put some sulfur on the wound and left it out.

[greenknight]

If it's soft instead of dry and callused over that's no good. Cut it off until clear of discoloration and start over. Sterilize the knife with alcohol before and between cuts.

[NeilR25]

I cut and cut and cut and it looks like the infection may have taken over. I took more than 12 inches off and stopped at the last 7 inches or so that looks fairly clean and white and I'm trying again. If this doesn't work it's curtains. Wish me luck...

[Steve Johnson]

I cut and cut and cut and it looks like the infection may have taken over. I took more than 12 inches off and stopped at the last 7 inches or so that looks fairly clean and white and I'm trying again. If this doesn't work it's curtains. Wish me luck...

Here in the US sulfur powder is easily available at local nurseries or on Amazon:

https://www.amazon.com/Bonide-141-Sulfu ... 161&sr=8-3

Give the freshly-exposed tissue a liberal dusting of sulfur powder and spread it all across the cut like this:

Echinocereus_pectinatus_'Coahuila'02062015_04.JPG (152.57 KiB) Viewed 1054 times

Leave the cutting upside down -- this is an example of how I did it when I had to do a "rootectomy" on an Echinocereus pectinatus:

Echinocereus_pectinatus_'Coahuila'03082015a.jpg (92.28 KiB) Viewed 1054 times

In the above example, I let the cutting sit upside down for a few weeks until the exposed surface formed a callus, and at that point I shook off the excess sulfur powder. If you follow this procedure, here's the next step:

• Fill a pot with cactus mix most of the way up, then put 1 or 2 inches of potting sand on top of the mix. You can find it on Amazon here:
  
  https://www.amazon.com/Original-Ingredi ... hdGY&psc=1

• Place the cutting on the sand -- you can dig down a little bit to stabilize it, but not too much.

• Don't even think about watering yet. The cutting needs to start growing new roots, and that will take time.

What you can do is mist the cutting so that it gets a little bit of hydration through the skin, misting once a month should be fine until summer is done. You'll need to keep it completely dry during fall and winter. When things warm up next spring, give the cutting a gentle (and I mean gentle) tug -- if there's no resistance, it hasn't started to root yet. But if you feel some resistance, you have new roots. Unpot the cutting, clean out the sand, and repot in cactus mix. Its root system won't be ready for deep watering yet, so here's the strategy I follow:

• Water lightly -- just enough to moisten the mix without accidentally drenching it. Do this every 2 weeks for about 6 weeks.

• Increase the amount of water for what I call "half-watering" -- midway between a sip and a soak. Do this every 2 weeks for 4 weeks.

This strategy teases the roots into growing as they seek out water while the mix is dry. After a couple of times with half-watering, the cutting will be ready for deep watering. I've used the strategy successfully on cacti that needed to grow new roots when their root systems were lacking, so this should work well for you. The main thing is -- be patient. Your cutting will get shriveled between now and then, so all you can do is watch and wait.

[NeilR25]

Steve, I dusted with rooting hormone and then covered the wound in sulfur. Is that the wrong order? Does the sulfur need to stick to the wound directly? Should I recut it?

[Steve Johnson]

Steve, I dusted with rooting hormone and then covered the wound in sulfur. Is that the wrong order? Does the sulfur need to stick to the wound directly? Should I recut it?

Yes -- the cut needs to be freshly-exposed tissue, then apply sulfur powder directly to the tissue while it's moist. I haven't found any use for rooting hormone with cacti, so the sulfur powder is all you need.

[NeilR25]

So I consulted with a cactus botanist and he gave my little guy about a 20% chance to survive. On his advice, I trimmed up the edges of the exposed ribs, which had some brown at the tips, and set it aside. It is now dusted with sulfur and sitting in a shady spot outside.

He also believes that is is not a true Pachycereus Pringlei but actually a rare Pachycereus hybrid which he has only seen a couple times before.

Please say a little prayer for my cactus son.