Just Killed My Horridus

8 years ago

I just got an expensive lesson in how quickly you can kill a Cycad by watering it when nighttime temperatures are below 50F. I was watering twice a week during the summer and the Horridus was doing very well. I recently replanted it to get the roots down deeper, and the root system looked incredibly good. In just three weeks of twice-weekly watering with the temperatures going below 50F, the entire caudex rotted and the roots fell off.

At this point, the plant is probably a goner but is there any procedure to have it possibly try to put out roots again? I will take it inside and stop watering. I'll cut the caudex down until the rot is gone.

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Josue (Zone 9b, Central, inland California)

8 years ago

I had an Encephalartos longifolius (in ground) snapped from the roots by one our dogs as they ran around the yard. I let what was left of the caudex callous over, then placed the remaining piece of caudex it in a pot in pure perlite. The leaves all dried out, but after about 10 months it sprouted roots and has just sent out it's first leaf. This all happened in summer though, and we are significantly warmer than where you are.

I did the same for an E. kisambo which I thought had rotted. After several months of sitting in perlite it leafed back out.

I'd check to see whether there is any portion of the caudex still in tact. If there is still a portion of healthy tissue, you may be able to salvage it. Let it dry, remove any rotted tissue and place it in a pot of pure perlite or pumice. Water it to keep it moist (the medium won't really hold much water, but will keep the caudex from drying out.) I would also put it in a place where it might receive some supplemental heat to speed up the process.

Good luck!

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Comments (8)

Dave in NoVA • N. Virginia • zone 7A
8 years ago
Would that apply to any Encephalartos?
westes Zone 9b California SF Bay thanked Dave in NoVA • N. Virginia • zone 7A
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westes Zone 9b California SF Bay
Original Author
8 years ago
@Dave in NoVA A cycad grower told me that you should stop watering all Encephalartos for the Winter when temperatures go below 50F. My immediate question is how do they then survive rain?

Apparently the South African climate these are native to is wet and humid in the summer, but dry and cold in the Winter. That is what we are trying to simulate.

I use gritty mix for soil, which is a very fast draining desert soil mix with no fine particles. There is no way water pooled in that soil, but even a small amount of permanent moisture was enough to rot the roots, combined with the lower nightly temperatures.

It's so frustrating to see this plant get established and then kill it so quickly.
westes Zone 9b California SF Bay
Original Author
8 years ago
@Josue, how often were you watering to keep the caudex from drying out?

I guess I should just bring it inside to baby it along in a mild climate during the winter.
tropicbreezent
8 years ago
E. horridus come from an arid climate and grow on slopes and ridges where what little rainfall they might get drains rapidly. Conditions are dry most of the time.
westes Zone 9b California SF Bay thanked tropicbreezent
Josue (Zone 9b, Central, inland California)
8 years ago
Mine do well in the ground. I have longifolius, arenarius and cerinus. We have cool, and usually wet, winters. Perhaps the rot was due to some sort of injury to the root system that allowed a fungus or bacteria to infect the wound? You said you recently re-potted it right? If I recall from your other posts, you were checking root growth pretty regularly.

I don't really know how often you should water the perlite, except that you should water enough to keep the caudex from drying. It shouldn't be too often I don't think. I didn't water mine very often at all and mine was outside in 100+ degree heat.
westes Zone 9b California SF Bay thanked Josue (Zone 9b, Central, inland California)
westes Zone 9b California SF Bay
Original Author
8 years ago
@Josue I guess I could substitute perlite with screened Turface (hard fired clay)?
plantsman56
8 years ago
It sounds like you lowered it in the pot which covered more stem with the moist soil. Horridus gets like 3 inches of rain each year in habitat. No reason to water twice a week. This might help.

http://cycadjungle.mysite.com/cycadjungle/Horticulture%2C%20Article%204%20Never%20throw%20away%20a%20cycad.htm
westes Zone 9b California SF Bay thanked plantsman56