Top dressed ammendments in soil/soilless start to finish

Hi everyone,
This summer I visited a commercial greenhouse operation where they were growing in coco slabs organically. They would peel back the plastic and apply dry amendments to the top of the slabs every so often. I'm not sure if they were using liquid ferts as well, but it seemed to working really good for tomatoes.

This had me thinking if it would be possible to do this with cannabis in a coco or peat based soilless mix. I know some of the bat guano products say that you can top-dress every week or so throughout the cycle. From what I understand the guano has already been broken down by beetles on the cave floors so it doesn not have to be cooked in a soil mix like blood meal.

What are some other amendments that don't have to be broken down and could be applied as a top dress? And has anyone tried something along these lines or think it might work?

Thanks

I grow in a coco coir mix using organic principles.
This mix of mine is about 50% coir 30% perlite and 20% worm castings.
I do (globally) mix in some fertilizers just not so much preferring to use what i call buried treasures.
These buried treasures are depending if their in veg or flowering pots zones of fertilizers.
I'll use like a few TBLSP 4-5 on the very bottom of these pots.
I use square pots so I'll place a TBLSP in each corner and 1 in the very center.
I opine that this method gives the roots options instead of if mix in globally.
I use teas and top dressing every 10-14 days to keep them happy.
I have been able to grow monster plants using these techniques.
I don't worry about different elements that have different break down rates I think that the life in my medium makes it all available soon enough.
Ratz

That sounds like a good mix. I think the earthworm casting definitely make a difference in a soilless mix. This is basically what I am interested in trying out. I don't want to use real soil or outside compost because of all the unwanted bugs and dieases that could possibly come with it.

The buried treasure idea is interesting to, reminds me of the spike method, where you take a spike and drive it into the soil to make a cavity where you pour dry amendments for the plant to find.

I am currently using bat guano top dressing on a crop in 100% coco that was fed bottled organic nutrients the first half of life. So far they are looking really healthy with a weekly dose of 1 tbsp each of high N and high P guano, per 5 gallon pot. I will see how it goes and post the results.

I have experimented top dressing many different amendments in - EWC/compost, lime, epsoma products, and guanos.

And yes you can... It is best to mix in the amendments/fertilizers into the top few inches of the soil, and not let it sit on top, otherwise they will get moldy with watering.

A point to remember is with any organic based fertilizer, it is essentially slow release. It has within it some soluble fertilizer, with the rest again slow release, and the fertilizer release rate has numerous factors... This is where you will incur variability, especially and particularly with granulated or slow release fertilizers that have not been specially formulated for cannabis (which I am sure will come to market soon).

You can add too much of any organic fertilizer if over applied.

Guanos will be "hotter" in this regard so be careful not to overapply, the fertilizer within should last a given amount of time. (so for you liquidcooled420 that's a good rate you started out on and I'd almost cut back half that dose, or wait a little more time before dosing again, unless you start to notice a deficiency, there should be a decent amount of elements in that amount of fertilizer plus you are applying every week, that could start to accumulate if over done. I know I've done that which is only why I'm cautioning it, but it was 1.5 gal pots not 5 gals so you may be okay with that feed rate and their needs, but you're also gonna need potash in there.. I donno what guano it is, I think epsoma's guano is 10-1-1 and has ca and mg and other traces in it.. hm.. i should check the bag..)

EWC is about the only thing you really can't overdo. Well, you can, but like, lol at that point dude you don't need that much ewc. whos wastes worm gold? For realz. That shit is gold lol.

You're still always going to need a PK booster, and during the right time during flowering... I hear, and I have found myself, that many in organics will get "airy" buds, even with good lighting, and this is the PK boost that needs to be applied at the proper time. Low levels of K throughout may also be warrented, and some Ca at certain points (and mg), is also going to be needed in soils as plants uptake elements from the media. Nearing the timing of a PK boost and to flush carbohydrates can be added to aid microbial activity, which can be added with EWC tea. (though soil doesn't get "flushed", it's just using h2o with nothing really added at the end.. well, depending lol.. I don't wanna get too deep, with say, using yucca and h2o with your flush, and yadda.. heh, or, heh, you could use ewc tea up to like the last week or so..)

EWC/EWC tea adds a host of things that are in any of those given bottled nutrients - some nitrogen and micro nutrients, microbes, chelating agents, etc., If plants are going bad, ewc is really good. Teas and EWC can be overdone, it's hard to do it, but you can. The only place ewc isn't warranted is in real hydro setups with regimented fertilizer schedules, rockwool, and stuff like that. Dirt or most coco setups can use ewc just fine. Theres plenty of better info around of course than I could give on the subject. Or any of these topics lol...

I opine that any worm casting above 20% of the mix will make for a heavy mix.
Meaning it will not want to dry down and have the possibility of drowning the roots.
I would never consider not using some WC in my top dressing for i see it as bringing in life.
The important thing to know about using guano's is it dives the pH hard.
When i use it in a tea i will bubble any guano for 24 hours first before adding other things.
This pH diving is hard on any microbe life but by bubbling for a day first is that the pH starts stabilizing.
When i use guano's in my top dressing i'll mix it with some oyster shell to counter balance this pH dive.
Ratz

azomite ...

I've never noticed any added benefit(s) of using azomite in my home made soil/less mixes.. I still have a huge bag too, as it goes a long way.. But it just never seemed to actually do much, plants were always basically the same with or without, so, that's my opinion, that in the end it is just an added expense. It doesn't actually add or help out any of the LC mixes or any of the other various soils recipes from here at IC I have made and tried over the years. Its something you can add for sure, I'd do perhaps 1/4 to 1/2 tbs per gallon of soil up to a point, like say for 50 gallons of soil I'd max out at about 10 or 15 tbs.

My second opinion on all this is that though making soil is fun and a good test of one's skill, in a way, heh, of following directions, lol, it's wayyyyyyy easier and cheaper to buy a good, balanced soil like happy frog or the like and go with that, and perhaps add in fertilizers as needed as they are used by the growing plant(s). My opinion is you will have just as good results, if not better, with much less work and expense put into it, particularly with small pot growing.

When thinking about rocks and such things like Azomite, green sand,glacial rock dust it seems forever to see results.
Then not sure if they appear to do anything but I still use them all.
I also have experimented with rock dust ie; Micronized of course!
Soft rock phosphate , Oyster shells and Gypsum comes to mind as a way of raising the Brix levels (sugar content) in a plant.
This one recipe of 6 parts Oyster shells ,3 parts Gypsum and 2 parts SRP used as a top dressing did great distressed when used in flowering but the plants responded well when in a vegetative state.
I am now very cautious of introducing any trace minerals in pots with plants in them preferring of adding these things when the mix is recycled.
I'll still use soft rock phosphate deep into flowering for it is one of the fungi favorite foods and the fungi attached to it, in little amounts over time rather then using bigger amounts.
Which brings up another point that if the mix is NOT recycled a peep will never have much of a chance of seeing any effects from these things.
LOL
Ratz

We nicknamed Happy Frog, Heavy Frog. It is way to dense to use right out of the bag. It might keep a plant green, but the growth is to slow from the lack of aeration. Not bad if you mix it, like with Blazeoneups recipe. Although imo, if your mixing it, may as well just start with plain old peat. That way you don't have to worry about that "batch" of the Heavy Frog.

Really like Guano as a top dressing. If you alternate between top dressings and compost tea, the top dressing will break down really fast allowing you to add more. Mixing it with EWC or some compost is a good idea as well. Help prevent caking.

Guano top dressing, compost tea, and soluble seaweed is a nice combo. Have a buddy who really hammers it, this last year his buds were so dense it was unreal... maybe a little to dense even. Made trimming a breeze though.

Mr^^

Dry organic mixes are some of the best you can ask for if you're looking for simplicity. Containers, beds, plants in ground it doesn't matter. I highly recommend Bio-Tone from Espoma and Starter Mix from Down To Earth. Both are absolutely fantastic.

-Funk

Great points, thanks everyone.