im ready to get shot down for this one (dont care so carry on) but i have spent a year doing this trial so thought i would share my results

basically over a year (5 grows, same strain) i have done half with rootgrow and half without, all other variables remained the same, new 600 watt bulb everytime.
i noticed no difference in root/speed of development, weight, resin production, smoke quality, growth pattern/speed, smell. naddah.

the only thing i can think off is that everything in the grow was so bang on the introduction off rootgrow made no difference, but i would say that wouldnt i
im not in for a discussion about the merits of this product just giving you my findings, i will personally not be using this product again.

I have only had good experiences with it. In my own experiences it has certainly speeded up the potting up process for me.
R.K.

I've recently started using the stuff and i've never seen my roots grow as fast of as healthy looking. theyre literally bright white and fat.

Fair enough!
I must admit I've not been impressed with it, but that could well be down to user error, I'll try it once more...... One day

you would only notice improved yield if you were to grow in beds.
the root stimulators will only speed up rooting by providing excess rooting hormones
once the plant fills to the size of the pot the yield wont change. ive noticed a massive improvement in yeild since doublepotting my plants (cut the bottom of a pot off, and put it ontop of a fully soiled pot
i personally use rhizotonic

well there's no denying mycorrizal fungi is a good thing but I wasn't really sold on the hit and miss way it's packaged, perhaps the gel might be better but it's a credit crunching 50 bucks!

Heya Drb , depends what you expected i guess , i certainly didn't expect yield potency and all that but then again it never claimed that , what are you using it for ? I would of thought as Lord Saines states doublepotting would double the secondary roots but as im confined to 6 - 11l pots .

Tis a fair point m8 you've obviously researched correctly and are acting upon your findings.

Would be interested to know what type of compost you were using, was it a peat based compost, loam based or using coir as a base ?

Also was you re-applying at each pot up and how ?

An interesting experiment nevertheless

i'm afraid i can leave some info now but will not be able to get back after this as i don't own a computer, borrow friends when the chance arises, like yesterday and today.

in regards to the variables i wasn't expecting a bigger yield/potency etc but if you are doing an experiment wouldn't you measure all variables possible? i did
i get 17 -23 ounces per 600 light depending on variety so wasn't expecting an improvement anyway

i use plagron light mix, with roughly 15-20% coca and a few handfuls of sand (i love sand and would recommend anybody to use it, every time a root hair comes across a grain of sand it splits in two and so on and so on} i'm not TOO anal about the measurements but wait till it looks/feels right in my hands.

i work on a 8 week schedule, potting up gradually, ending up in 7 litre pots (yes i applied every pot up, i thought if your going to test, lets go for it, using recommended amounts/instructions}

i use bio bizz nutes and like the phrase "feed once a week weakly" i add mg when the plants tell me too

i also use trichoderma and am willing to accept that if i left this out of my control pots i would have noticed a difference without the rootgrow, i just couldn't bring myself to, i love it as much as sand!

can't think of anything else of the top of my head, hope this helps. feel free to ask some more questions but i doubt i will see another computer for a week or so

take it easy all

Heya Drb , the resulting compost is a main harvest for me ,

worm tunnel
Click to view attachment

i use a simlar ie root grow and trichoderma with the addition of minerals and such , the worm tunnel is the said compost from two successful reused grows on Warlock with added rock dust and sand , the worm activity needs to be seen to believed , this has been grass seeded .
Does what it says on the tin for me i like it , ive just potted up to day so with thread in mind i omitted the rootgrow and added a few things , just potted into west ji adv plus , i usually use the adv plus as to the lower peat content , three neat , three rootgrow and one rootgrow-trichoderma-rockdust-kelp-ewc , all maxicropped in . Ill root um through then into a planter only variable of course is flowering , i will not be able to control the adverse growing conditions as we can with our other plants but thats where bactos and fungis kick in .

Click to view attachment

umm rootbound one on the left was given to me like that

I like your style shewiff

Thanks for answering the questions drbrookfieldcambridge

Interesting that you find Trichoderma to have a greater effect on root size than VAM's, how much more rootmass do you think you get using trichoderma ? Do you use the sand to supply minerals or is that mostly to ensure more division in the roots, if you don't mind me asking ?

Thanks for your time,
Felix.

this is not to answer the question but to say what a good thing sand is to add to your soil/ compo. It depends on where the sand was from as to the minerals it provides but as well as minerals it also provides excellent drainage and air pockets, on top of that it provides a surface for bacteria to transport it's self along, via gravity, as bacteria cannot travel long distance (talking microbe distance) under it's own propulsion. Fungi however can 'grow' throughout a soil and will use such a surface to grow off, break down this particle and transport it back to the root ( depending on the type of fungi).
I have every faith in mycorrizal and other fungi!

Interesting stuff. Sand comes in a variety of grain sizes, and from different rocks and minerals. What kind of grain sizes would be suitable for adding to compost? I kept gerbils for a few years, and used really fine grained sand for them. Then you've got your sand for sandboxes, sand for fishtanks, sand for using on icy pavements during the winter etc. There's lots of sand out there!

In my own experience, I've just tried Rootgrow and I'm getting better root growth and health than ever before As for the sand, the main compost I'm using has 5% sand added from the manufacturer, and I'll keep it like that for now, but it would still be good to know what kind of sand would be good for compost

Most sand in the uk for horticultural purposes is washed sharps composed of 90+% silica or quartz, its inert.

Sand does not cause roots to branch.

Rootgrows fungi will only just survive or slowly die out in peat composts, so is of little help in sustaining plants in this medium.

On the other hand trichoderma will thrive on the roots of plants in this medium, I suspect add to the speeding up the demise of any mycorrhiza unfortunate as to be inhabiting the same medium.

horticultural sand would be a good place to start

So rootgrow wont work to well with Plagron composts there made from peat, oops been wasting my money a bit then

Does this mean that adding Rootgrow (or webby's granules) to peat compost is best avoided, or does it beneficial to the roots while they're still alive? After reading other posts on the subject I gather that composts with loam are preferrable in order to give the fungi a sustainable environment. Are there any other options other than loam one might use to tend to these friendly fungi in peat compost?

Rootgrow actually used to say on their web site about the problem of their fungi surviving in pure peat composts, it seems to be gone now, bad for business I suppose.

light mix is little more than blended peats with a few chemical and organic nutrients.

Its pretty close to an inert hydroponic medium, as is coir and sand.

For most micro herds to do well, you want a good living/dying medium, + real mineral reserves.

Things that help the micro heard and keep it healthy are things like rock dust, guano, rotted manure, rock phosphate, calcified seaweed, seaweed meal, worm casts, well rotted manure, compost teas, soil/loam, the west plus wood etc.

mycorrhiza developed in real soil in symbiosis with plant roots, they benefit the plant by extracting nutrients from rock particles, and the organic material in the soil as it breaks down, its hypha in fact are part of the break down process, the mycorrhiza grow into and from the roots, they give the plant the nutrients they extract from the soil, in return the plant gives the fungi carbohydrates.

The plant is perfectly capable of absorbing free chemical fertilisers present in the soil moisture.

A quick question OT if you don't mind ?

Have recently begun to experiment with fortified (by adding Rockdust, seaweed meal, calcified seaweed and rock guano) West+ Advanced, is that the 'West plus wood' you refer to above ? As this isn't made with peat would this make for a better environment for the microherd ?

Given that peat is mildly anti bacterial and anti fungal is is a case of simply using composts that aren't made from peat ? Or is it a little more complex than that ? Is coir a good environment for VAM's or is it better suited to Trichoderma ?

Looking back over that it's more than just a quick question, sorry

tbh fella, I once used west plus advanced and found it not so good as mp with john innes, I wasn't using rootgrow, trichoderma, rockdust etc, just maxicrop when potting up and at regular intervals with feed etc....Im still using westlands mp (now with rootgrow and calcified seaweed and rockdust)with JI but the compost aint as good as it used to be

rock dust is great stuff for fungal growth, I use it in my aact's, the fine dust that is. Woody stuff is also great for fungi but whatever your mix it has to have good structure as it's a mad world down there, I think it's something like 15% organic material and the rest goes into structure.... From memory I'll check later

Felix West +, is wood residue that has been de-lignified.

I believe this is done with bacterial and fungal fermentation, ie its well on the way through the decomposition stage towards becoming humus.

In other words westlands have found a cocktail of microbes that assist composting wood. For years people have known that fresh wood contains all sorts of goodies that are good for the soil, but composting them takes years, if wood chip is added to soil, the bacteria/fungi that break down wood will rob any free nitrogen from the soil as it becomes available, this totally depletes the soil of N. People have tried all sorts to compost wood chip, sawdust and shavings, mixing piles of wood with chicken shit or watering with nitrate fertilisers, eventually it does work but it takes years, making a superb rich compost.

So west + is a good substance for supporting breakdown bacteria and fungus species as well as mycorrhizals, adding rock dust gives extra fuel to continue the process.

Westlands advanced is 50% peat the rest is west + a little sand/grit and fertiliser.

Peat contain little or no nutrient there is nothing to support the breakdown process its just a pretty dead medium, even with the addition of lime to partly neutralize its acidity and a few nutrients its breakdown is very slow.

Coir supports trichodermas, in fact it often comes containing them.

There is nothing wrong with peat or coir as such, peat was chosen by compost manufacturers, because it is pretty much inert when dug up due to being so acidic, ie it carries no fungal or bacterial root diseases. Its cheap to mine, all they have to do is mill it, that makes a fluffy light medium, add a few chemical fertilisers and some lime, a drop of wetting agent and you have a medium with good water/air holding capacity that roots can grow through easily.

Really this is a hydroponic medium with the chemicals already added dry, it keeps a long time in bags as long as it is kept on the dry side, all the grower has to do is add the hydro/water and away you go, its something that cost little to produce.

Thank you for taking the time to answer that one OT

Let me see if I've got this straight. Pure peat composts or composts made mostly from peat will not easily support a viable micro herd due to the chemistry of peat. Composts composed of loam will support good microbial activity but tend to be a little heavy and compact in the pot, composts made from coir will support trichoderma well, are very light and transport water extremely well within the pot.

Westlands+ Advanced Compost will support an active microherd because it has already been extensively decomposed and has a good structure but can be lacking in minerals so could benefit from adding Rockdust, Mearl and possibly seaweed. Loam might also bring something to the mix if a little was added, I'm thinking 5 - 10% maybe

West+ certainly does encourage rapid and strong roots, will have to see how it performs with added loam

@botanics, does seem that loam (JI) really brings something to a compost that benefits the microherd

Yeah, the JI formulas seem to be amongst the best in my view, after all they've been around for 70 plus years, im thinking of dumping westland tbh and going straight for JI 2 then up to JI 3 for further repots, but my only reservations are as you've previously stated they do tend to compact and make waterering difficult, I also worry about root oxygen levels in this scenario, but maybe with some inert additions it could be loosend up...

Got to agree with you on the compaction issue with JI, perhaps some coir would help lighten the mix and also encourage Trichoderma at the same time ? I ran a little experiment over the summer using some Apollo 11 clones and the ones in a mix that contained loam did seem to do somewhat better than ones without but the difference wasn't huge.

sand works great, you get a much more even watering with it, combine it with the coco as suggested and I'm sure you'll be a happy chappy

Coco will give you capilary attraction, it absorbes water soaks it up and spreads it through it's fibre and other fibres.
Sand gives you gravity, the water slides down it's surface easily. What you get is best of both, this is what I mean when I say soil structure. There is a shed load more to it than that tho

Interesting ideas there, might just do a couple of different ratio mixes and see what the results are...Nice one I Zimbra

Heya , sands no good for the mycorrhizal fungi im affraid , on golf courses grasses up and around surrounding bunkers greens etc are measured up to 70 percent less infection of inoculated areas , to me it seems the fungis/fungi are ok leaving on peat bases all be it a a significantly lower level the trouble farmer/agriculturalist are having so spend to most time researching its getting the fungis or more to the point the specific fungi to spread to the required areas etc , we solve that by keeping things at micro level (11ltr pots) , how about chopping some inoculated roots rolled in coir .

that is interesting stuff there sheriff, I don't know why that could be really could be a number of things I spose. I can't see the amount of sand used in pots to be an issue tho, many experiments for mycorrizal fungi are conducted in a medium with sand in and cactus also rely on the fungi. Golf courses have been nuked with chemicals to keep them green perhaps this could be a factor combined with human traffic pressing down on the sharp sand and cutting the hyphae preventing it from getting a strong hold, did it say what the bacterial percentage was? I don't know, I will turn to google eh eh

Edit to say that cutting up the root and adding it back works very well! Much better than root grow but I spose root grow gives you the start but once you've used it as long as you don't kill it you don't need to buy it again