Cannabis Root Systems

There is virtually no tested information that I can find on cannabis root systems so I thought I would relay the anectdotal knowledge that I have learned about this aspect of OD cannabis growing.

Just a foreword, this topic can be very important to OD growers but is seldom considered when planning a grow. Those growing in containers can make a fatal decision to choose a strain with agressive roots or plant a full indica in a low lying area where their intolerace of excessive moisture around their roots is quickly observed. Some sativa's however, don't seem to have any concern at all with occasionally soaked soil. Knowing the characteristics of the roots can be very important.

Just as a general rule, most of the strains I have grown have had small to moderate root systems and I feel most strains probably fall into that category. By small, I mean they would easily fit into a 2-3 gallon container without really binding up. Moderate root development fits in about a 5 gallon bucket, even though they exceed the buckets width latterally, they easily fit if soil is removed.
There are certainly exceptions to these generalizations, and as many as there are strains I suspect.

100%-90% indicas and afghanis. - Although there are some big full indicas, many are compact with small root systems. Single colas, small statured branched plants under 4-5' dont have lots of weight to support ,dont suffer wind damage easily as they are not high profile and make great container plants and grow well outdoors in areas that don't have deep soil. I have one site where at 10" a clank is heard when one hits the solid rock shelf. These plants tolerate this condition well and grow without any problems there. Anytime big roots could be a problem, these are the strains to look at.

100%-90% Sativa's. - My experience with full sativas is less but I do believe that sativa root systems are somewhat dependent upon the point of origination of the native parent strains. I have come to believe that equatorial sativas have a wide snowshoe type of system but not necessarily a big tap root. Many don't have huge yields or weighty buds and even though they may grow tall, they don't offer much resistance to the eliments.
I think there is another group that originates further from the equator that shows variation in root systems depending on climate and rainfall and often do express a significant tap root. I know that Mexican sativa has a very different root system than columbian.

Hybrids: This category of plants have root systems that are all over the board and unfortunately, this is what many of us are growing. They range from KC-33 which has an agressive vigorous root sytem that can send a tap root to 4' and if it does blow over, roots just develop on the side of the root ball and the plant takes off again, contrasted against Early Riser, which has picked up an indica yield in the cross, but posseses a typical equatorial sativa root system that has difficulty supporting the heavy indica flower development that is wasnt intended to support and blows over in the wind easily and doesn't recover well.
Hybrid crosses can result in any combination of traits from the parents. While smaller statured hybrids still seem to have smaller root systems, there are some big yielding plants with small root systems that won't handle drought or wind, and some big strains with little yield with a deeper tap root than normal. There can be a lot of variation in root structure in the larger hybrids.

Generally, it seems to me that the biggest, deepest root systems come from hybrids where both parents were big and the growth is sativa dominated. These strains seem to have the wide lateral aspect from the sativa but the tap root that came with the big indica has also been hybridized and is exaggerated in size. These are the OD gorilla plants. There aren't many in my view. It is impossible to know what kind of root development will be seen with mixed breeds such as 4 ways or crossed hybrids as they can recieve traits from any or all of the parents in the line.

Someday, when more breeders start breeding for outdoor, this topic will recieve more interest. Most of the breeders today simply don't have a clue as to root development or structure of their strains as they are interested in the part of the plant that grows above grade and only notice roots if they cause problems such as nute sensitivity. Much of the breeding is done inside and the breeder wouldn't even know if the plants root system will hold up the vegetive growth that's been enhanced by the breeder. There are some breeders doing work however.

KC Brains breeds for outdoor and he has at least 4 strains that are the most vigorous with the largest root systems available at least for the strains and breeders that I am familiar with . He has really stood alone for years but now some talented new people are on the scene doing some good work. BreederBrad2 and Mandala are doing lots of OD research which will eventually lead them to root system issues and the development of the OD holy grail: a short, heavy yielding plant with a 4' tap root that can find water in the desert and resist hurricane force winds.

If you have additional info, please add it. Don't worry about your beliefs being different than mine, there is so much variation here, we could all be right or wrong.
Any thoughts?
What kind of root systems are seen in autoflowerers?

i have come to beleave the roots system of most plants weather it be mj or oak trees that the spread of roots is in conjuction with the height and width of the plant ..i no thats what your saying but growing condisions also play a roll [type of soil ,moisture in soil]
i grow my outdoor stuff in swamps and my roots you would think would become rootrot and i have never exsperanced this and i find the taproots on a couple a fews ago were atleast a good foot into the deep waters..

as far as strain i can only say its a pruple and i thought it had more indica then it dose .now after reading your post i dont no tho...the reason i beleave this is because of the wide leaf and it stays about 5 to 6 ft tall most yrs but i have had a couple shoot up to 8 ft and more..

but even with the tap root running that deep in the swamp i tend to always have some that blow over in a good storm but i figure some is due to the soil being saturated and loosening its hold...


do you beleave there is a diffrence when growing from clones ..a seed plant which can grow to a massive state would carry the massive root growth...

i am not a breeder or anything but an old hippie pothead but i cant imagin that the breeders out there are not taking all this into consideration when doing their genetic thing already..i no theres some that just throw everything together and hope for the best but they get weeded out [not meaning to be funny] with weaker strains after awhile and then we will see a great rush to get this by who's left ...

i no i personely would love to grow the perfect plant outdoors ..but i beleave to do that we need to move out of the shadows to grow and until the laws change for most of us the idea of the perfect plant is unatainable..


sorry i am a having a little wake and bake and got rambling..i hope i stayed on topic....


herb weedmen..

From what I have heard regarding root systems they generally are equal to the girth of the plant whether talking oak trees or MJ. I have a friend in the landscaping business and he says that most people do not understand that most of the root system of a tree is just several inches below the ground. The roots extend the width of the canopy.

My personal experience with the MJ root system would be from digging out last season’s roots. I usually see a taproot of around 8-12inchs and the lateral growth is usually less than the canopy of the plant. I think it has to do with my watering practices. I provide enough water that they don’t venture far from the plant base.

In the long run this causes me some problems because I feed 20-20-20 and the veg growth becomes extensive and when the budding begins a good portion of my plants lean or fall over. Staking is a necessity for me and something I would like to get away from. You would think a plant bent over would be great for flowering, something like tying down but because of mold I do not like my plants close to the ground.

Not sure I could do much to change this I mean we all loosen our soil and water so it stands to reason a plant with large flowers will brake branches and tend to fall over do to the loose and damp soil.

Maybe with less watering the lateral root growth would extend helping the plant stand up. Not sure but good subject because the roots are the foundation of a good healthy plant.

afghani grafted onto malawi gold rootstock?
nice thread.

Everything I have seen indicates that few plants put a true taproot deeper than 2 feet......

Hi herb,
I agree with your assertion that the root system mimics the plant growth to some extent, but I think thats where difference comes in. There are some strains , that have inherited the yield from one of the parents and the root development of another. These are the plants that always blow over. I certainly agree with you that soil conditions do play a big part.

Hey hamstring, I agree with your landscaping friend and I too dig up roots as I use the same holes year after year. I think the lateral roots are probably there spreading out to the width of the plant or to the "drip line", just hairlike and not really visible. In fact, Ive seen some sativa strains that have a shallow, very fine mass of roots up to 4' in diameter but extending into the soil no more than a foot, with no real tap root at all. As far as your plants blowing over with yield weight, that may be a result of breeding/strain. You wouldn't believe the number of strains I have abandoned due to that one effect. Dr. Atomics BBXNL has that problem and many many others. I consider that a result of hybridization. In nature, plants generally don't have more growth than the stem/roots can handle and thats even if you feed them alot.

Thats one possibilty simple gardner. If cannabis wasnt an annual plant, i would have already tried it.

Hi Backcountry, I guess I agree with that. at least most cannabis plants. I think the greatest tap root size is seen in large, sativa dominated growth for an sativa/indica hybrid. Ive found these strains to have a wide variety of root systems from shallow and wide to deep rooted plants. I have often considered that soil conditions may have a great impact on the extensiveness of any root system simply because of the fact that when i plant a very big strain, the root system will be similar to the other large annual native weeds that grow around them and many of them extend well beyond 2' deep. I have one location in a river bottom that floods each winter and drops 6" of new sandy rich topsoil. The earth is black, soft and full of earthworms. Ive grown numerous strains in the area, but only those large sativa/indicas will thrive. Every other category blows over in the soft black dirt.

I don't think too many people grow big plants anymore. As i often grow in single plant sites, I find them advantageous to grow. They're different in a number of respects, including root systems.

I used to believe that variation was limited to large sativa/indica
hybrids but i grew 2 strains last year that had no tap root. None.
These were small statured indica's, but most cannabis i believe does have a tap root even if small.

Its really one of the reasons that i believe most growers would benefit greatly from finding a few strains they like and then comming to know the strain and its characteristics, rather than growing one unfamiliar strain after another. I have found it takes about 4-5 years of growing a strain to really learn how it will respond under any given condition and what its real attributes are.

hey silver..when you talk about tall plants ,i cant help but think of the compeatting plants around them making them chase the sun..kinda like the old rush tune were the maples and the oaks are fighting to be the tallest..and what kind of effects that has a root system if more energys put into growing tall and not growing the roots need to support such a plant..maybe this is were you find the weakest plants or roots...

i have been growing the same weed for 15 yrs now and have seen the way they grow ,change more from weather conditions then anything else..dry summers i'll find roots ways away from my plants in search of moisture and in the wetter summers i find that my branches arnt so brittel eather that they snap frow weight...i have easy access to my grows so i can spend as much time i need to care for them but i no that these changes can be seen..

effects in yeild as well as leafs production will change in this strain of mine when growing in compation with other plants..if i croud them they tend to stretch a shit load and my bud size seems to drop..


i used to keep a book with notes a grow log i guess of my outdoor stuff when i first stated grow this strain..i'll see if i can find it and see what the diffrence was from yr to yr on root production ,yeild and weather conditions..


herb weedmen

cannabis roots will grow according to condition, and what they are afforded via soil, and space..

larger containers/holes, = larger rootsystem = larger plant.

smaller containers/holes = smaller roots and plant.

while, of course, each plant from seed, each different strain, will be limited by its maximum potential in all aspects... providing the best conditions above and below ground, will allow each plant to reach that potential.

Peace, bub.

Hey Herb. I too think many strains will develop larger and deeper roots in search of moisture, but I think it may be strain dependent. I beleive small statured strains with small roots can will only stretch out for a limited distance while larger strains may be more agressive.

Hi OG bub. I certainly agree that providing the best conditions up and down will always produce the best results in all respects, hands down.

I do think there is lots of variation however. For example, I can grow 4 plants and it b e a misdemeanor, so in my yard, i generally grow 4 in 5 gallon buckets. Last year I grew Nirvana's affie, super crystal, brain damage and mikado. Neither the affie or the super chrystal filled the entire bucket with roots over the length of the grow. The brain damage and the mikado both really overgrew the bucket and became root restricted towards the end of the grow. I was having extra work to water daily and fertilize those 2 . Clearly, if I was going to do an OD container grow, I would be much better off with the Afghani or the super crystal.

And hence, thats why i started the discussion. I see growers sometimes write that they are starting a container grow and i see a strain choice that will likely lead to disappointment unless constant care can be given.

Just my thinkin. Sb

each seed has its own make up and the way it grows is pre determind before the seed is ever planted..the only other thing that can effect it would be enviroment..


herb weedmen

"Thats one possibilty simple gardner. If cannabis wasnt an annual plant, i would have already tried it."

Could it not be done through herbaceous grafting? It's commonly done with tomatoes and watermelons, may open new doors for guerilla growers:

http://www.avrdc.org/LC/tomato/grafting.pdf

i would imagin grafting is possible with weed..but what would you graft to..sapplings other green soft plants..

i no theres roadside weed that grows wild out in indiana..it dosnt get ya hi but it reseeds every yr and grows wild..so maybe it would be considerd a bi annual plant..


herb weedmen

Great discussion SB, I'll just contribute my experience for posterity.

I have been growing THSeeds SAGE for a while now. For those unfamiliar, its a Haze/Afg hybrid. Ive grown out many seeds, both my own backcrosses and breeder direct. This plant has shown great results outdoors for me. I choose large growing sativa looking plants, and find much of what you say to be true in terms of the root mass. The plants show wide variability above the ground and below. Paying special attention to root mass has dramatically improved my outdoor success. Deeper root masses are more tolerant of drought and wind, as you describe.

Im at about 34 N lat and get well into October before any danger of frost. I start my trees in a hole deeper than wide: 1'w x 3' deep. I have found that SAGE will send a tap root deeper than 2', if the soil is loose. Wide reaching roots develop slowly over the season, and Ive gotten 10'+ plants with 4' wide roots out a 1' wide hole. However, when I dig a wider hole (say 3') with a depth of 2' the results have been worse with the same plant (clone). The tap struggles to penetrate denser soil conditions, and the feed roots dont get any wider despite the easier path I provide.

Not sure how this applies to others, but take it for what its worth. Choosing a plant with an aggressive root mass and planting it accordingly has given me 10'+ plants with drought and wind tolerance. Long live the SAGE!

Hey 3BM. I grow some 10 footers as well- usually sativa dominated growth/indica stone. In fact, I believe we havent seen more acknowledgement and discussion in this thread is because so few growers are growing big strains and don't know that root systems are varied, especially in the bigger strains. Once rooted, some can withstand drought and other problems much better and the last thing you would want to do with them is plant them in a bucket. YOu have me interested in sage.

herb weedman, indiana used to be full of ditch weed. It was here too but in most states they have worked to completely irradicate it and have succeeded to some extent.


Simple gardner, it probably could but I don't know how. It seems to me you would have to do it indoors in a pre grow setting as the healing time would delay the maturation of the plant. If done indoors until healed and then set out, it may work.

i think to grow the perfect plant from roots to colas you would need to know the strains history and it would have to be 100% one strain..the genedic dragon rears its head when you think of all the crossed strains out there...and the diffrent possiblitys that each strain has ..so a root system to a mix strain may grow diffrent when grown in diffrent mediums or enviroment condisions...

ditch weed being a strain that maybe or may have been on its way to being a very good candidate for this idea..it had grown without cultivation until the people killed it off..altho a very adaptable plant it is possible that its needs would change over time and the enviroment may have come more of a factor in the perfect plant..

there are some plants not mj but others that grow best when the roots are crowded..

sorry i no the roots were the topic of this thread and i have more then once stepped out of bounce but i think it is all related in the importence of the root system and other factors that have effects on its growth..

thanks

herb weedmen

What would you guys say if I have sativa looking plant with very poor root system?(it's about 2-3 months old and just got into new bigger potting pot while ago)

You guys discuss on a level I can hardly keep up with.
Probably because of my lack of growing experience.

I know you guys mainly talk about outdoor cannabis root systems, but if you have any thoughts on growing in pots indoors, please do share them

Could the success of sogging partailly be accredited to using pots that are minimum twice as tall as they are wide? If the tap root has the ability to dig deep during the first weeks, thereby providing more takeoff points for the secondary roots, you might think growing either from seed or clone in a tall (3) and narrow (1) pots would be wise...

Do the cannabis roots grow like in these videos?
http://www.superoots.com/videos/index.htm

great read

thats exactly how they grow..or should grow..but they dont get burned back by the air..

heres one for ya's..i just started my outdoor strains and found a couple had popped double taproots from one bean..now i have a couple sets of twins growing and i also had a couple that looked like they came out of their shells backwards ..the leaf came out first and the tap root stayed in the shell..

now a couple of these strains are autoflower and mite exsplain in part but a couple of my orange sunshine shot twins also..

its grow time here ..sun would ever come out and warm things a bit ,would be nice..


herb weedmen

Vol Funk said:

What would you guys say if I have sativa looking plant with very poor root system?(it's about 2-3 months old and just got into new bigger potting pot while ago)

Click to expand...

many times the roots do not develop because the plant does not like the soil, or simply because it is a weak genetic trait that individual plant has.
wait now that it is in the new soil, and do not over water nor over feed. hopefully, things will get better.

one thing to keep and eye on to help root systems develop are the soil structure and soil compression. sure, the soil needs to be loose, but not too loose, not too packed... same with water levels during the beginning stages of growth, not too wet, not too dry... gotta have an eye for it, because these things depend upon the individual environments as well as plant genetics, as already mentioned by the other gentlemen.

Paz