Who trims roots when repotting?

i cant figure out how to post a poll, so just post your answer this is for the smaller type cacti such as Lophophora, Ariocarpus, Astrophytum and others along those lines.

I trim the tap roots on my cactus when i repot. I have noticed a huge difference here with growth rates, anyone else?

Hi Kada, I have added your poll. You should be able to add a poll at the bottom of your text editor screen. There should be an "options" prompt & an "Add a pool" prompt, there is a + & - icon which open the menus for both. If it is not there it may be disabled, I will look into it.

In aswer to your question. I have never heard of anyone doing this. I think I would be too scared to trim a tap root

Do you have any litereature you can link to so I can read about this technique?

Thanks.

ohh i didn't see the +- things i am not always very internat savy

i have no links sorry. i learned it when i moved here to taiwan and met some serious cactus breeders (those crazy asian astro loonies). the idea is this. when you ar erepotting your cactus, cut a certain amoun of the tap root down (one guy does 1/3, another 1/2 etc...seems most do in the 1/3-2/3 range). Why? because the tap root takes in very little water/nutes. cutting the tap, promotes smaller roots (capillary roots) so you get more water/nute intake as a result. i have been doing it for a couple years now and i do really notice a difference!

One of the guys i often chat with showed me how much he cut his A. myriostigma...jesus! abotu 4/5 he cut off....only 1-2 cm below the plant. but he has 15 cm Astrophytum in 8ish years....so i listen

Wow!, thanks for that Kada, I'll havta give it a go.

Awesome insight.
I just potted my two biggest Astros into larger pots (a myriopstigma and an ornatum) - never touched the roots.
I've got a 1cm astro nudum cv zebra which when I pot up in october this year I will give the chop.
thanks,
Calycium

just make sure you leave it out to dry for a week or so...just like letting a cutting callouse. if you chop and plant it may rot.

Kada wrote:

i have no links sorry. i learned it when i moved here to taiwan and met some serious cactus breeders (those crazy asian astro loonies). the idea is this. when you ar erepotting your cactus, cut a certain amoun of the tap root down (one guy does 1/3, another 1/2 etc...seems most do in the 1/3-2/3 range). Why? because the tap root takes in very little water/nutes. cutting the tap, promotes smaller roots (capillary roots) so you get more water/nute intake as a result. i have been doing it for a couple years now and i do really notice a difference!

I dunno if i could bring myself to trim a heap of tap root off, its the last thing i would think about trimming, BUT, i will give it a go next time on a few plants, it makes sense to me, i just hope the plants agree

Depends how you grow them I think. If you barely water then the tap root serves a purpose as a water holding vessel. Over time the cactus will develop other tap roots.

It is an interesting idea but not somthing I will try. Id rather encourage the growth of capillaries by watering/ferting more. Cacti are designed as sponges and will suck up water when ever it is available so I dont think you need to do anything else to make them do this.

Perhaps your friends are bigger because he waters/ferts more often because of his idea of trimming the roots.

im not sure if its all about watering/fertilizing. i water mine every few days and they all have ferts mixed into the soil. this procedure was originally done in Japan, but now many breeders in asia (china, taiwan, thailand etc) do this, cause it really speeds things up. for the conditions here, it works amazing! if you want to try it but are scared, try it with something hardy like Lophophora or Astrophytum first.

Sounds like an interesting technique kada, I may consider giving it a try with atleast one of my plants next season. Depends if I can bear to cut into the root, shouldn't be a big problem with the potting media I use: http://forum.auscactiforum.net/mexican-cacti-f14/ariocarpus-potting-media-for-australian-conditions-t8.htm

This got me wondering, alot of (if not all) my Astrophytum sp. didn't seem to have any noticable sort of tap root that I could see (the ones I got bare-rooted anyway), should I be worried that they have all been grafted plants?

Although de-grafted Astros don't seem to decrease in value like de-grafted Arios do.

Might try it on an A. retusus, will post all details and results and expect those who trial this method to report back. I might even organise a public log book/diary type thing next season to see what peoples results are with this technique.

How much dessication can the smaller roots tolerate? ie when allowing the taproot cut to heal?

many people here leave them out of soil for a month or so (its hot here). i leave them ot for a week or so and plant them withough watering for a couple weeks (usually).

i think a lot of Astrophytum were grafted at some point, not many people hard grow them....One of the few genera, liek you said, that looses no value...unless of course tehir shape changes.

ever wonder why some peoples 15 cm lophs are only in a 10cm tall pot?

keep in mind, this is jsut growing more roots, it's not going to make your cacti grow as fast as a grafted one....i am talking more about mayeb an extra cm or 2 every couple years (which is a lot for slow growers)

i was repotting some Obregonia denegrii so thought i would post some pictures (i cant turn bold off sorry).

here is a before and after pic. aside from teh more root thing of trimming roots, jsut think about all tehse little capillary roots getting repotted and all bunched together and broken....that is just the recipe for rot.

I cut off tap root of Astrophytum asterias from 2 years old seedlings and then cut off roots following every year.
I cut root around the end of August. If you feed prenty of water to asterias in hot season they grow quite quickly even own rooted.
Asterias lost a tap root has just fine roots only and never die even feed prenty of water in hot season.
I do same way for myriostigma.

2 years old asterias cv miracle kabuto, before cutting tap root

2 years old asterias cv miracle kabuto, after cutting tap root
Very easy repotting, just inserting into soil
I use this method many years.