Soil grow, do u flush?

VerdantGreen · Jan 21, 2012

Microbeman said:
citations?

i read it in a post by Mr Fista - possibly in the 'yellowing isnt necessarily a lack of N' thread that you were referring to. i think it related mostly to N uptake - roots became less effective at this as the plant aged and began to senesce. kind of made sense to me but i'm afraid i cant give you a reference.

VG

VerdantGreen · Jan 21, 2012

here's the thread about yellowing an N - definitely worth a read for anyone wanting to learn about this.
https://www.icmag.com/ic/showthread.php?t=190022&highlight=root+nitrogen

VerdantGreen · Jan 21, 2012

interesting article about root efficiency and age
http://www.ufrb.edu.br/nutricaomineral/nmp_pg_09/Nutrient%20Acquisition%20by%20Plants.%20An%20Ecological%20Perspective,%201ed,%202005/8-187.pdf

it seems that plants roots that grow 'unpruned' in a large soil mass would lose root efficiency quicker with age than those that experience root pruning and the subsequent growth of new roots (as might happen in a smaller pot or airpot). so once again pot size will be a major factor in how your plant will senesce and will account for some differences in our anecdotal experience.

right that's enough homework for a saturday morning. need coffee now....

mad librettist · Jan 21, 2012

VerdantGreen said:
interesting article about root efficiency and age
http://www.ufrb.edu.br/nutricaomineral/nmp_pg_09/Nutrient%20Acquisition%20by%20Plants.%20An%20Ecological%20Perspective,%201ed,%202005/8-187.pdf

it seems that plants roots that grow 'unpruned' in a large soil mass would lose root efficiency quicker with age than those that experience root pruning and the subsequent growth of new roots (as might happen in a smaller pot or airpot). so once again pot size will be a major factor in how your plant will senesce and will account for some differences in our anecdotal experience.

right that's enough homework for a saturday morning. need coffee now....

VG, that's just a proper description of root binding. My cannabis lives 6 months at the very most, usually more like 4.5 months, not long enough to fill the pot with old roots.

it's important to note that smart pots DO NOT contribute to root pruning, and do not encourage more "new" roots in any way. If you have a tree in a smart pot, and another tree in the same size plastic pot, they will develop symptoms of root binding at about the same time. This is because, despite the "air pruning", the age of the roots does not change.

The only way to mitigate damage from the roots growing old is to cut them back with a knife.

VerdantGreen · Jan 21, 2012

mad, having used airpots for three runs now (and just gone back to regular ones) that makes sense - i found no increase in yield and even wondered if the dry soil around the edges actually reduced the amount of useable soil significantly.

mad librettist · Jan 21, 2012

VerdantGreen said:
mad, having used airpots for three runs now (and just gone back to regular ones) that makes sense - i found no increase in yield and even wondered if the dry soil around the edges actually reduced the amount of useable soil significantly.

if it's drying out too much, then yes, you are losing crucial root space!

however once the edges are well colonized by roots, the dryness is resolved. (can be achieved by targeted misting with water)

still, that means the smart pot is creating a problem I have to solve. Is the extra gas exchange worth it?

mad librettist · Jan 21, 2012

btw if anyone is wondering if that means I am against smart pots -

it depends on your grow environment. in my garden, ambient RH is very low right now, and they are indeed a nuisance.

I would be much better off with square plastic pots as I could maximize volume that way.

OrganicOzarks · Jan 21, 2012

I have never understood the flushing with organic soil idea. I don't flush my tomatoes, peppers, green onion, herbs, squash, zucchini, etc... So why would I flush my Cannabis? I have tried side by sides to see if there was a difference, and guess what I found out? I couldn't tell the slightest bit of difference. Maybe I just don't know enough to know anything.

VerdantGreen · Jan 21, 2012

i think the fundamental difference would be that you smoke weed and eat all the vegetables that you listed above.

OrganicOzarks · Jan 21, 2012

VerdantGreen said:
i think the fundamental difference would be that you smoke weed and eat all the vegetables that you listed above.

Why does that matter? You are ingesting all of them. I honestly do not get it. can you explain in more detail.

VerdantGreen · Jan 21, 2012

weed that has stayed green up until harvest is not as nice to smoke as weed that has yellowed before harvest.

admittedly, what actually causes it to yellow is a matter for debate... but i know the above statement is true. curing also helps smoking quality but ime there is no substitute for a nice 'ugly' finish. lots of factors effect how and when this occurs and how much, including genetics. i run the same cuts over and over again and measure my soil amendments carefully, and i can confidently say that in my setup/environment, getting the Nutrients to run short towards the end of the cycle helps smoking quality without reducing my yields.

VG

LubdaNugs · Jan 21, 2012

I use a "super soil" mixture. I add nothing, but water throughout my grow. I would guess the only way to achieve a flush in my system would be to cut the level of "super soil". I have used a 60% - 75% mix in the past, I might try 50% to see what happens.

SeaMaiden · Jan 21, 2012

BurnOne said:
The plant is putting on a lot of weight the last two weeks before harvest. That's assuming we are harvesting at the correct time. She is trying to survive and reproduce and needs a lot of energy (food) to do so. I feed the most right before harvest. I never get a fishy taste when using fish and never taste bat guano when using guano. Nor worm casting, dolomite, peat or seaweed taste.
I want the most yield possible. I think this is a better solution than microbiology studies, expensive additives and pure nonsense we read here every day.
A well fed plant can yield as much a 30% more than a starved plant at the end of its grow period.
And why spend so much time and effort during months of growing a plant only to miss out on the two most important weeks?
Burn1

Duly noted. Perhaps I should have explained my own methods a little better, but in my current situation I'm building and maintaining the soil food web to the best of my ability. And so, in that endeavor, my goal is to feed the soil as well as I can, and let that in turn feed the plant, or allows the plant to feed itself. But, a 30% difference in yield is appreciable so I'll look into this more in depth. I'm not afraid of FE, guano or the like, though I prefer to use urine when and where I can simply because it's not only free, but mixes quite easily and has plenty of bio-available nutrients (assuming I'm using fresh, I believe once it's decomposed into NH3/NH4 that further conversion/decomposition is necessary).

VerdantGreen said:
im not so sure that the plant is able to process food through the roots so well as it approaches harvest time. roots have been shown to get 'tired' and inefficient at that time. i find that if you can encourage the plant to start using what it has stored in it's leaves then that gives a great boost in the last few weeks. i like my plants to look yellow and starved by harvest - but with fat buds
and yield wise i seem to do just fine. 10 oz from my last grow with a 250 HPS.

VG

D'oh! Contradiction! Mah brain, mah brain!

mad librettist said:
VG, that's just a proper description of root binding. My cannabis lives 6 months at the very most, usually more like 4.5 months, not long enough to fill the pot with old roots.

it's important to note that smart pots DO NOT contribute to root pruning, and do not encourage more "new" roots in any way. If you have a tree in a smart pot, and another tree in the same size plastic pot, they will develop symptoms of root binding at about the same time. This is because, despite the "air pruning", the age of the roots does not change.

The only way to mitigate damage from the roots growing old is to cut them back with a knife.

I LOVE cutting roots with my special knife. People look askance at me, some aghast, even (especially young men who equate pruning to cutting off fingers and arms), but damn if my plants don't respond well to it. Except Camellia, apparently Camellias don't appreciate that sort of attention very much.

Microbeman · Jan 21, 2012

VerdantGreen said:
mad, having used airpots for three runs now (and just gone back to regular ones) that makes sense - i found no increase in yield and even wondered if the dry soil around the edges actually reduced the amount of useable soil significantly.

I always wondered about this, having never used smart pots.

Microbeman · Jan 21, 2012

mad librettist said:
btw if anyone is wondering if that means I am against smart pots -

it depends on your grow environment. in my garden, ambient RH is very low right now, and they are indeed a nuisance.

I would be much better off with square plastic pots as I could maximize volume that way.

Excellent point....larger surface area to boot.

Microbeman · Jan 21, 2012

VerdantGreen said:
i think the fundamental difference would be that you smoke weed and eat all the vegetables that you listed above.

We don't flush our homegrown tobaccy

Relentless · Jan 21, 2012

last 1-2 weeks i just give water.. i feed water feed water weeks 1-7 usually.. i start off with 1/4 and by week 4-5 im usually at a full dose of nutes, then i start backing down and stop calmag and nutes at end of 7.

VerdantGreen · Jan 21, 2012

Microbeman said:
We don't flush our homegrown tobaccy

ah, but i bet you grow it in open ground and not in pots loaded with ferts :blowbubbles:

VG

i think the big discrepancy in our anecdotal evidence comes from the fact that i grow big plants in smallish pots and they need quite a rich soil, whearas you grow in much bigger pots where most of the nutrition can come from compost, EWC etc.

mad librettist · Jan 22, 2012

VerdantGreen said:
ah, but i bet you grow it in open ground and not in pots loaded with ferts

VG

i think the big discrepancy in our anecdotal evidence comes from the fact that i grow big plants in smallish pots and they need quite a rich soil, whearas you grow in much bigger pots where most of the nutrition can come from compost, EWC etc.

sounds reasonable to me!

what about Ca, K, etc? what about which sugars are found in senescing plants vs. healthy ones?

redneck shogun · Jan 22, 2012

I have to admit I am too lazy to modify my program so that my soil runs out of food at harvest. I respect your skills VG you are fine master gardener but I like just adding in compost after a run to my soil and letting it fly. Some yellow and some don't but it all smokes well enough for me so I don't really care.

Soil grow, do u flush?

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