Trich roots and moisture - mythbusting time

[Quixote]

What makes a San Pedro cactus want to grow more roots? Wet soil? Moist soil? Or dry soil? I heard all three. Which is correct?

Also, for a small T. Pach. in a pot in a window-sill - will it expand its root system during wintertime (in north europe) or will it be completely dormant all winter because the lack of light?

Edited October 26, 2011 by Quixote

[cactuscarl]

I'm no expert but in my limited experience i believe moist soil is best as long as the cut is totally sealed. I've had cuts shoot roots in damp soil then totally stop once the soil dries and not do anything until i watered again

There my two cents

[Quixote]

Interesting, Carl, thanks for sharing. So if a cactus already has some roots, it will stop growing them until it gets moisture again? Sounds logical somehow. But others have assured me that the cactus only grows roots looking for moisture when it's been sitting dry for some time.. which would also "logically" make some sense ?

[Sir Jeans]

I usually root trichs in totally bone dry soil - they seem to do just fine, but I don't know if they would do better if the soil was moist. Moisture risks rot, and I heard an argument that there's no point providing moisture to a plant with no roots.

But this begs a question - can a root-less trich cutting still detect soil moisture and respond to it? If it can't, then it probably would make no difference if the soil was wet or dry.

I'm very interested in this issue myself - hopefully some more knowledgeable people will come and share their wisdom!

[tipz]

Well spines and areoles absorb moisture.

So after a cutting is calloused and planted, if the soil is moistened and water is absorbed through the aereoles, It may prompt the plant to throw roots. It's just a theory but i always water my calloused cuttings straight away.

If i am doing a bare rooted transplant, then i will leave dry for a period of time before its first water.

EDIT : quixote, a root stimulant like rhizotonic or similar would promote root mass. It is quite effective

Edited October 27, 2011 by tipz

[tipz]

double post

Edited October 27, 2011 by tipz

[Foo]

Ive got 3 cutts yet to develop roots. 1 has new growth and the second has started growing a big pup. Only since theve been outside and watered though.

[zelly]

What makes a San Pedro cactus want to grow more roots?

Mother Nature and the process of survival of the fittest.

Since the plant cannot pick itself up & relocate, well then it's got to send out roots looking for sufficient moisture & nutrients. The roots also have to provide support for the plant.

can a root-less trich cutting still detect soil moisture and respond to it?

An un-rooted trich cut will send out roots looking for moisture. If left out of the soil long enough, some species will grow aerial roots.

If left out of the soil even after aerial roots start forming, the cutting will literally dehydrate itself, feeding plant energies into growing more roots, searching for moisture and nutrients.

The newly forming roots gets the energy & moisture they need from the cutting, much in the same way a cutting will produce pups sometimes long before any new roots are established.

If the roots find sufficient moisture, the cutting & pups flourishes & grows. As the cutting grows, so do the roots. In a healthy plant, the roots never stop growing, although they may slow down quite a bit during dormancy.

a small T. Pach. in a pot in a window-sill - will it expand its root system during wintertime (in north europe)?

Yes. It's in an artificial environment. The plant (and roots) will continue to grow, although much more slowly.

[Bretloth]

From my experience the biggest thing is not to disturb the plant whilst it is growing roots, as in checking your cut for roots every week or something, that only slows things down. I just put my cuts straight into moist potting mix out of the bag, leave in the shade under cover until I see new growth then they go out with the rest and start watering.

[TommyChesnutt]

some good opinions on here.

in my experience, many factors such as soil drainage come into play when rooting cacti. i use a method - ie, seal the callous, plant in very well draining soil,

don't water again until new growth is formed (it's a cactus. yes, it likes water, but it's still a cactus!) - and then water in ascending frequencies (starting from about a month apart, 12 months later around twice a week). i find this to be a great method of weaning a cutting into growth pumping mode!

for those planting trichs in soil that has limited drainage, and provides not much oxygen for the roots, it's best to hold off on the water for longer and keep the frequency far apart (suppose once every two weeks.) that way, the roots won't drown, and will spread pretty effectively in search for what it needs - once you have an established plant (say 3-4 years old) the growth output may be relatively the same.

cacti is a long-term hobby, and for that it's a good one ;)

[Gunter]

i've seen them root dry and in plain water...

lol

i think gravity, time and darkness help trigger hormone responses that promote the induction of callus tissue and then root formation. Roots seem to grow out from the vascular bundle but can occur on cuttings that have had all meristems and areoles cut from them. Plants can often absorb water without roots but it is common for cactus roots to grow in contact with moisture. Adventitious roots can grow from the stems of crowded or rootbound plants...

Edited October 27, 2011 by Gunter

[Quixote]

So, basically, we can conclude from the experience shared in this thread that nobody knows for sure?

Or that T.Pachanoi doesn't care at all if the soil is wet or dry?

Edited October 29, 2011 by Quixote

[zelly]

So, basically, we can conclude from the experience shared in this thread that nobody knows for sure?

First hand experience is the best teacher.

I know what works for me in my growing environment, just as gunter or (insert name) knows what works for them in their growing environment.

How could anybody know what works best in your growing environment other than yourself?

[CβL]

I have had the best experience with a nice and dry cut, the soil rather damp, and a fair amount of sunlight and warmth (i.e. I don't think anything of mine moved a root during this year's NZ winter). The sunlight is essential for quick rooting (proper fibrous roots, not fat anchor roots). It'll be a lot slower without it.

To test for roots, I prod the top of the cactus and judge the vibrational frequency and damping ratio (seriously). Prod a cactus with established roots, and compare it to a cutting sitting in soil to see what I mean. The one with roots has a lower vibrational frequency, and the damping ratio also appears to be way lower (it will vibrate for a second or so usually).

Edited October 30, 2011 by βluntmuffin

[Distracted]

Concerning calloused San Pedro cuttings in particular

"Plant several inches deep and water sparingly and infrequently until you see noticeable growth on the cactus. Lack of water and receiving small infrequent waterings will stimulate root formation faster than the presence of water. They form foots to find and recover water, not in response to an abundance of water"

"A handy trick is to plant the healed cuttings in pure dry sand and repot them in soil only once nice roots are actively forming."

Trout, K 2001 Trout's Notes on the Cultivation & Propagation of Cacti, A Better Days Publication, p19

[Sola]

As there are many differnet experiences with successful growth of roots under different circumstances here, I think it is safe to say that Trichocereus is a species that has a wide tolerance of conditions.

Personally I have thrown a fresh cut in the ground and watered it just the same as everything in the garden around it and although it seemed slower to grow, and therefore I assume produce roots it still grew.

Some that I put in pots fresh (cuts) as an experiment and watered more as the plants around it required, rotted and died.

I don't think this will always be the case, they seem quite variable and the weather conditions in your area will make a massive difference.

I personally think it's always better to callous them first and then keep them on the drier side for a couple weeks then they should be fine to slowly increase the water followed by fertiliser.

They are pretty tough tough and depending on the species quite suitable to Australian conditions as SA (South America) is influenced by the same weather patterns that dominate our weather.

Apart from the uplifting and folding/ volcanic action that land mass is quite similar to Australia. We're just on an extremely old and weathered piece of the Earth's mantel.

Check out ENSO events if you're interested, basically when we're in drought they get more rain and vice versa.

There's a lot of technical info in that stuff but basically when the SOI (Souther Oscillation Index) is positive the East coast of Australia is likely to experience wetter than average conditions and the opposite is likely for SA.

BTW since records have been kept La nina or positive SOI events have occured two years in a row. I'm not saying it'll be the same intensity or that it will occur just that it is likely.

As cacti in SA can cope with this it is very likely it will survive and thrive on the other side of the Pacific Ocean.

Sorry, just rabbited on a bit but hope it helps.

[Quixote]

Thanks for all replies. I wish I lived in Australia where I could plant this cactus in the garden, but I live in the far north and my cactus lives in a pot in the window

[mutant]

let it calous properly. if in doubt let it a bit more.

place in dry soil.

when rootlets begin, I place on top of wet soil

you can't check to often if it rooted, because you might damage them. They're fragile as they come.

I do not do this and check them constantly, but I am into relentless propagating all the time. makes my day