How can I tell if a cactus outgrew its pot?

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brixtertabun
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How can I tell if a cactus outgrew its pot?

Post by brixtertabun »

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ElieEstephane
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Re: How can I tell if a cactus outgrew its pot?

Post by ElieEstephane »

brixtertabun wrote:I repotted my cacti last year into a better mix. After having my mammilaria die from the original peaty mix, I found out that store bought cactus potting mix sucks and they would benefit from more inorganic content like pumice. My cacti seems to agree since they grew a lot compared to last year. I use mostly pumice (70 to 80%) and I fertilize every watering.

I ask because I looked under the pots and saw some roots poking. (I suspected a root mealybug problem and I'm unfortunately right :( ). I read in the forums that cacti should be repotted every 2-3 years. My faster growing jungle cacti have some roots growing out of the holes. Can I tell from the roots if it out grew its pot? Another bit I read is you can tell if the cacti is close to reaching the edge of the pot. My problem is my cacti grow diferently. I have a globular cactus which will reach the edge faster, a columnar cactus that doesn't get much thicker, and a cactus that has a lots of offsets so it is 'wider' but the main cactus is not thick.

I only have 5 cacti and I live in a tropical climate so timing is not an issue. What's your criteria to say that a cactus needs a bigger pot?
Since the water is gonna drain out of the holes at the bottom, that's the most humid place in the pot. That's why the roots are gonna poke out of there. Looking for the humidity. All my cacti do if it's humid for a week or 2. But when forget to water or it's very hot and dry the hole roots die out.
As for repotting, pull the cactus and soil out of the pot and you'll see how the roots are doing. If the soil feels surrounded by the roots roots but not very dense you're still fine. If the soil feels very tight together and you can see lots of roots intermingling, it's time to repot.
Concering root mealybugs, i had the problem once. I removed all the soil from the roots, and dumped boiling water on the old soil to sterilize it then threw it away to avoid spreading the infection. Next thing you do is submerge the roots in 50 degrees celsius water for a minute or 2. That should kill the bugs. (Look online for the exact procedure on root mealybugs). And/or you can try a systemic insecticide. Good luck!
There are more cacti in heaven and earth, Horatio, than are dreamt of in your philosophy.
One of the few cactus lovers in Lebanon (zone 11a) :mrgreen:
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7george
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Re: How can I tell if a cactus outgrew its pot?

Post by 7george »

Once in 2 - 3 years is an advice for temperate climate and ~ normal growth rate. If the cactus (cacti) is bigger, wider than the pot it's time to re-pot for sure. Rot or another disease is another reason. Young seedlings will need even several transplants a year.
Last edited by 7george on Sun Oct 01, 2017 8:53 pm, edited 1 time in total.
If your cacti mess in your job just forget about the job.
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cactushobbyman
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Re: How can I tell if a cactus outgrew its pot?

Post by cactushobbyman »

Plastic pots: squeeze the pot. If it is hard and not forgiving, root bound. Clay pots: I have had the pot split/crack from being root bound.
brixtertabun
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Re: How can I tell if a cactus outgrew its pot?

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greenknight
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Re: How can I tell if a cactus outgrew its pot?

Post by greenknight »

I've had good success plunging the pots in a soap solution to kill root mealybugs. The method is described here: viewtopic.php?f=3&t=30560&p=270953&hili ... ug#p270837

I'm sure you can't get Fels Naptha there, but any plain soap should work. It can be hard to find just plain soap these days, but maybe if you shop around...
Spence :mrgreen:
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ElieEstephane
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Re: How can I tell if a cactus outgrew its pot?

Post by ElieEstephane »

greenknight wrote:I've had good success plunging the pots in a soap solution to kill root mealybugs. The method is described here: viewtopic.php?f=3&t=30560&p=270953&hili ... ug#p270837

I'm sure you can't get Fels Naptha there, but any plain soap should work. It can be hard to find just plain soap these days, but maybe if you shop around...
I found that article very interesting! Did it bloom eventually? :lol:
I live in an area where only olives are grown, Lots of centennial and millenial trees (optuntias seem to love their company too). We have a sort of traditionnal soap made from olive oil and lye only, no additives at all. You think that coukd work in case of a future infection? I don't like using systemics because i dont want bees pollinating the die!
Last edited by ElieEstephane on Wed Oct 04, 2017 7:31 am, edited 1 time in total.
There are more cacti in heaven and earth, Horatio, than are dreamt of in your philosophy.
One of the few cactus lovers in Lebanon (zone 11a) :mrgreen:
brixtertabun
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Re: How can I tell if a cactus outgrew its pot?

Post by brixtertabun »

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greenknight
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Re: How can I tell if a cactus outgrew its pot?

Post by greenknight »

That olive oil soap should work fine. No problem waiting until the next watering - root mealybugs cause slow decline, a week won't make that much difference.

No, my rescue Echinopsis has still shown no signs of blooming. Still thriving though. :dontknow:
Spence :mrgreen:
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