Cactus cutting gone bad?

[Chindit]

Ha! I can see where you are going here. The temperature in the house is always 68.

[Steve Johnson]

Ha! I can see where you are going here. The temperature in the house is always 68.

Okay, good to know. Bear in mind that desert cacti are used to temperature extremes, so I don't think your cactus would get shocked by going from 68 to the mid-upper 50s when you do the outdoor root cleaning. A constant of 68 indoors also means that it won't grow during winter, but cacti need a cool winter rest anyway. When you repot the "parent" cactus and the offsets, keep them dry and don't even think about watering until spring. Desert cacti also need heat in the spring-summer growing season -- since your parent cactus and offsets will be near a south-facing window, I'm pretty sure they'll get enough heat during the day. If in doubt, get an indoor thermometer and place it close to the plants. Highs above 75 in spring and summer, and they should be happy. Even better -- keep them outdoors in the growing season, bring them indoors for the fall and winter. Is that doable for you?

[Chindit]

Hmm...seems i didn't successfully post my message yesterday.
Anyway, my plan is--weather permitting--to do a root cleaning outside on Sat. I'll take photos of the roots at that time--and also of the offsets--post them, and then await your next instructions. In the meantime I'll bring the cactus into the basement afterwards and just lay it flat.

Leaving a cactus outside here might not work. We are overrun with deer and I think they might eat cacti. (they will come up to the porch). I'll have to investigate this issue.
Also, the pumice arrived today.
Thanks Steve

[Steve Johnson]

Anyway, my plan is--weather permitting--to do a root cleaning outside on Sat. I'll take photos of the roots at that time--and also of the offsets--post them, and then await your next instructions. In the meantime I'll bring the cactus into the basement afterwards and just lay it flat.

Sounds good. I know of growers in the midwest and northeast who overwinter their cacti in a basement, so leaving your cactus bare-root and your offsets (no roots yet) down there should be fine until you're ready to repot either toward the end of this month or sometime next month. I'd still like to have you set up a fan for some decent airflow while they're in limbo.

Leaving a cactus outside here might not work. We are overrun with deer and I think they might eat cacti. (they will come up to the porch). I'll have to investigate this issue.

Yeah, that could be a problem -- especially since the spines on your cactus are too small and sparse to deter the wildlife.

Also, the pumice arrived today.

Excellent. Don't forget about the potting sand you'll need for your offsets' rooting pots.

Thanks Steve

Always a pleasure!

[jerrytheplater]

Leaving a cactus outside here might not work. We are overrun with deer and I think they might eat cacti. (they will come up to the porch). I'll have to investigate this issue.

I too am overrun with deer. And mice. And Chipmunks.

I have yet to see deer eat any of my cacti. All that are out are spiny except for the Lophophora. They are out at ground level overnight. I do see mouse or Chipmunk nibbles on my plants. Even my Frailea which are pretty spiny.

July 5, 2022 Chipmunk damage on my deck on Frailea parviflora

rsz 2022-7-5 Chipmunk damage.jpg (123.33 KiB) Viewed 1626 times

Here it is about 6 weeks later on Aug 15, 2022 greatly recovered.

rsz 2022-8-15 Damage recovery 1.jpg (117.92 KiB) Viewed 1626 times

If I leave my carnivorous plants out off of my deck they will get eaten to some extent. I have to keep chicken wire over top of them. The deer or groundhogs will go after my water lilies since they are in tubs and easy to reach.

[Chindit]

Jerry, after living in North-western NJ for over 30 years I am all too familiar with deer assaults on plants! But maybe they are unfamiliar with cacti and avoid them if there are better food options available. Anyway, maybe not worth trying to find out.

[Steve Johnson]

Jerry, after living in North-western NJ for over 30 years I am all too familiar with deer assaults on plants! But maybe they are unfamiliar with cacti and avoid them if there are better food options available. Anyway, maybe not worth trying to find out.

Yep, I agree.

[Chindit]

One more quick question--and this may be a stupid question: when you cut off an offset and put sulfur powder on the "parent" plant, should you also put the powder on the offset where it was cut?

[Steve Johnson]

One more quick question--and this may be a stupid question: when you cut off an offset and put sulfur powder on the "parent" plant, should you also put the powder on the offset where it was cut?

If it's a clean break, no. However, if you see freshly-exposed green tissue when you remove one or both of the offsets, you will. Offsets that can be pulled off by hand with minimal effort usually don't expose their tissues, which is why I call it a clean break.

[Chindit]

Thanks again Steve

[Steve Johnson]

Thanks again Steve

Always glad to help whenever I can!

[Chindit]

Here are some pics of my root cleaning over the weekend (decided to do it in my basement).
Please let me know if this cleaning looks good and what the next steps would be.
(the plant meanwhile is lying flat in the basement).
Thanks!

[Steve Johnson]

Good news and bad news. First, the good news -- you did a wonderful job of cleaning the roots. Now for the bad news:

Nematode_gall1.jpg (68.17 KiB) Viewed 1477 times

Nematode_gall2.jpg (69.04 KiB) Viewed 1477 times

Nematode_gall3.jpg (70.35 KiB) Viewed 1477 times

The nodules you see in the red circles look suspiciously like the galls produced by root knot nematodes. Nematodes are essentially eelworms feeding on the roots. Per CactiGuide's Pests and Diseases page:

• "Nematodes live below the soil and therefore are not noticed until they've done significant damage. Slowed or reduced growth above ground, often signifies trouble below. Nematodes are not likely to be found in potted plants, but in those planted in the ground. As a result, the plant must be dug up to inspect the roots. Digging up an established plant is not desirable, but if no other symptoms are visible, it is sometimes necessary...the presence of the nematodes is apparent by the knobby tuber-like bumps on the root system."

Not likely, but not impossible either, and I suspect that your cactus was potted or repotted with garden soil sometime in the past -- the only way for root knot nematodes to infest potted cacti. Insecticides are completely ineffective, so the only remedy would be with a nematicide. Unfortunately I don't know of anyone on the forum who can guide you on the right product and application.

Before we jump to hasty conclusions...

Root_chop-chop.jpg (67.3 KiB) Viewed 1477 times

...I'd like you to cut the nodule in photo #3 all the way through on the red line I indicated. Then post a close-up photo of the nodule's exposed cross section, as close up as you can get. If you do in fact have a nematode infestation, it'll be apparent to you, me, and everyone else following this thread. From there we can figure out what to do next. Worst-case scenario and the parent cactus can't be saved, you'll have 2 "insurance plants" in the form of the offsets you can root.

[Chindit]

Wow--this is getting really complicated.
I'll perform the surgery in the next day or so and post the pics. (I'm really curious myself what's lurking in that "bulb").
Thanks Steve.

[Steve Johnson]

Wow--this is getting really complicated.
I'll perform the surgery in the next day or so and post the pics. (I'm really curious myself what's lurking in that "bulb").
Thanks Steve.

Yeah, I know -- this is the most difficult case I've encountered in my 13 years on the forum. Unfortunately the only USDA-trained expert who knows these matters well disappeared from the forum in 2021, so all I can offer is guesswork on whether my nematode diagnosis is correct.