Is this seedling rootbound?

[taozen]

Well, I'm pretty sure it's not but maybe it is, if not it is almost, what do you say?

[Gunter]

what do you say?

does it matter?

no it isn't rootbound

some San Pedro cacti are affected more than others by being root bound anyway, many are cliff dwellers used to cramped root quarters

others are forest dwellers used to rich acidic soils

it doesn't seem to show signs of root stress or being root bound, but a word about the roots of cacti:

the roots of these plants are of two type, the primary roots and what has been called ephemeral roots

the primary roots anchor the plant, the ephemeral roots are the feeding roots, when you see a thick root grow from the base of a cutting this is the primary root

in wet conditions the feeder roots/ephemeral roots grow out, they grow rapidly, they respond to moisture and grow out to feed and take in moisture

however when the plant experiences drought or dry cycles, something common in the Andes, then the feeder roots are abscised from the main roots much like a deciduous tree sheds leaves in the fall

the relative purposes of this is multifold, it helps build the rhizosphere by supplying organic material to decay in the root zone, this allows the colonization of idea symbiotic microbes and helps build soil where the roots feed

another main function of this strategy is to prevent the plant from wasting energy, nutrients and water on roots that are not providing moisture or food, it protects the plant from excess water loss through the feeder roots

some cultivators including myself consider this aspect of cactus biology when feeding and watering, I provide cycles of wet and dry that are many days long each, the feeder roots take a few days to grow out and can last quite awhile, so i don't just water here and there, i water profusely for periods of time, keeping the soil moist and nice for the feeder roots, and then i get things get fairy dry and stay that way for awhile, sometimes weeks

as far as being root bound, it is not the same with cacti as it is with trees where a main root can girdle the plant by circling around in the container, and if the plant does get seemingly rootbound these cacti do respond well to pruning back their roots,

i have seen under-potting stunt plants, however this is more of a function of the root mass to be able to supply the nutrition and moisture needed for ideal growth, in smaller containers this is more difficult for plants as they start to get larger, this is why plants in large containers and in the ground get enormous and grow very fast, it is not because smaller containers and plants get rootbound, it is because a small container simply cannot contain enough feeder roots to supply enough food and moisture to allow the plant to get large

[lophty_tricho]

Nice answer! More than the asker of the question expected I'd say. Good observations, thanks

[mutant]

Cool post Archaea.

OP> this couldn't be root bound. It's too small for this pot.

[taozen]

Of course it matters! specially when I get this cactus-solid quality information!!! It felt like reading a book with that post, boy do you learn something new everyday. So, maybe when it grow big enough I can transplant some cacti to the ground. Here in Guatemala, we get 6 months of predominantly dry weather and 6 months of rainy weather, of course its not contant but I dont think its much like the Andes either, so, we'll see. ATM I'm getting ready to sow about 300 tricho seeds of 6 dif varieties maybe I'll come here to get some of this vital quality advice, thanks!