Slightly over-potted?

[iann]

This is quite a lot of pot for a modest Copiapoa.

echinata-0721.jpg (54.11 KiB) Viewed 2022 times

That pot isn't sitting quite straight though ...

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Might struggle to get all those roots in a smaller pot. They don't call it megarhiza for nothing.

echinata-0721.jpg (52.61 KiB) Viewed 2022 times

[adetheproducer]

Think you could do with a bigger pot mate.

[CactusFanDan]

Haha megarhiza by name and nature. Perhaps I should repot my seedlings from their tiny communal seedling pot.

[DaveW]

Just been re-potting my Eriosyce, and a large percentage of them seem to have some sort of tuberous roots. I noticed even Neoporteria villosa had. I had previously potted them in a mixture where I had sieved out all fines or dust by passing it over fly screen, even the dry soil and peat used had been passed through a quarter inch sieve or riddle then similarly had all the dust removed, meaning it too had a granular texture. The mixture also contained grit and cat litter therefore was very open since I had found in the past that removing the fines as well as aerating the mixture produced very good root growth. The main problem is if you buy commercial potting materials and put them over a fly screen you loose about quarter of the material you bought, which makes it expensive!

There certainly seems to be truth in that certain soil mixtures produce more tuberous roots versus fibrous roots than others do.

[bruno]

I would add: They don't call it echinata for nothing, great plant

[iann]

I would add: They don't call it echinata for nothing, great plant

Yes, much more hedgehoggy than my plain E. megarhiza, although just as big-rooty.

[iann]

Dave, my soil for these and just about every cactus is based on non-sieved John Innes. It does include plenty of cat litter and grit though, so it is certainly quite open. Plants with large roots like this tend to get an extra-coarse mix so that I can water them properly without the pot taking a month to dry out.

[DaveW]

I was talking to Roger Ferryman at the BCSS Convention Ian and he said that the separation of tuberous rooted versus fibrous rooted forms like Ritter's Neoporteria wagenknechtii (fibrous rooted) and his tuberous rooted N. wagenknechtii v. napina was artificial since he had found both tuberous and fibrous rooted examples within the same population, presumably depending on the type of soil they were growing in. What exactly it is with the type of soil that triggers more tuberous rooting is open to question. Juan Acosta put it down to the amount of humus in the mix, but whether it is just the more open texture mineral and similar type soils containing more solid matter like grit and cat litter have is a matter for conjecture?

I can't recall having found any of my Neoporteria villosa's with tuberous roots in the past, but I did this time. Obviously some species are always tuberous rooted, but whether the potting soil makes for larger ones I don't know. I once had a Turbinicarpus that had developed a long carrot like tuberous root and had to be put in a "long tom pot", but I can't recall any other of my Turbinicarpus ever having such a big carrot like root.

What is interesting with very large tuberous roots that eventually fill the pot is where all the potting soil they displace goes to?

[CactusFanDan]

What is interesting with very large tuberous roots that eventually fill the pot is where all the potting soil they displace goes to?

Some species seem to actively digest the soil mix and break down bulk mineral aggregates, while others just don't seem as capable of doing so. Of course some of the soluble matter will be taken up, but also the mixture will be compacted over time as the roots push out on the mix. Some species whose roots really like to grow tend to turn their square pots into round pots by the time they need to be repotted. Lophophora williamsii v. caespitosa is most guilty of that.

[iann]

Here's another one. Copiapoa hypogaea ssp tenuissima.

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All C. hypogaea have big tuberous roots, and this one has obviously filled the pot and is reaching out for more.

tenuissima-0727a.jpg (40.66 KiB) Viewed 1899 times

[oldcat61]

Scary - looks like I need to un-pot a few likely suspects. I did notice that my C. tenuissima is rising out of the pot a bit. Thanks for the heads up. Sue

[Steve Johnson]

Here's another one. Copiapoa hypogaea ssp tenuissima.

Odd question for you, Ian -- when you transplant cacti, do you center them in the pot? My reason for asking is that I'm pretty good at centering mine, and I notice that a number of them go through "continental drift" as their root growth favors one side of the pot over time. Don't want to hijack your thread here, so I may post up a few examples with a thread I'd like to start if I have the time. Perhaps an interesting aspect of cactus behavior that doesn't get much coverage...

[DaveW]

Maybe the roots favour the cooler side of the pot away from the sun Steve? With pots plunged into the ground or plants bedded in the ground one side of the soil would not be hotter than the other. With ordinary plants the old gardeners used to plunge clay pots in peat or sand on the staging's to keep them cool and moister. It could also be related to where the most nutrients occur in the pot since the reverse may be true for porous clay pots if there is greater evaporation on the sunny side of an unglazed clay pot drawing more nutrients that side, as detailed in the link below:-

http://www.plantphysiol.org/content/10/3/511.full.pdf" onclick="window.open(this.href);return false;

From the Web:-

"Growing plants in containers, however, alters root growth and function and can change root morphology. Numerous factors influence root growth in containers. Roots of container-grown plants are subjected to temperature and moisture extremes not normally found in field production. The effects of substrate aeration as well as water holding capacity interact with different pot characteristics, resulting in changes to root morphology."

Interesting quotes from the following link:-

Plastic Pots (light coloured)

"Heat and cool quickly so plant roots and microorganisms are not damaged as easily even when in a sunny location. Generally have more drainage holes than terracotta, ceramic and concrete pots".

Plastic Pots (black).

"Heat up quickly and provide little insulation. Avoid using in full sun but OK to use in shady positions."

Terracotta, Ceramic and Concrete Pots.

"These materials retain heat for long periods – whilst some species may benefit from this, the potting mix can become very hot in sunny positions, killing microorganisms and burning plant roots. These materials are porous so draw moisture from the potting mix and dry out more quickly. Plants require more frequent watering (higher maintenance)."

http://themicrogardener.com/choosing-a- ... nd-cons-2/" onclick="window.open(this.href);return false;

As a user of plastic pots, as most cactus and other succulent growers are in the UK Steve, I can't say I have noticed uneven growth of roots in them. Certainly you don't get all the roots concentrated around the outside of the pot as we did with clay or terracotta pots when we used then in the 1960's. But I have never used glazed ceramic pots so cannot say if they are better.

[CactusFanDan]

Here's another one. Copiapoa hypogaea ssp tenuissima.

Odd question for you, Ian -- when you transplant cacti, do you center them in the pot? My reason for asking is that I'm pretty good at centering mine, and I notice that a number of them go through "continental drift" as their root growth favors one side of the pot over time. Don't want to hijack your thread here, so I may post up a few examples with a thread I'd like to start if I have the time. Perhaps an interesting aspect of cactus behavior that doesn't get much coverage...

I find I often try to get the plant central, but the action of soil mix being poured into one side of the pot can move them when I'm filling up the pot. It's not a big deal though really and sometimes it can be desirable if you're sticking a label in the pot, particularly if you're underpotting something really spiny.

[iann]

I try to plant in the middle, but sometimes the roots just won't fit and I just have to jam them in wherever I can. Although I mostly like to give plants room for their roots, in cases like this I just use the smallest pot that the roots will fit in, which is still usually pretty big compared to the above-ground part.