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.
What kind of root systems are seen in autoflowerers?
Last edited by silverback; 04-27-2008 at 04:34 AM..