How long does it take for a dry amendment to ACTUALLY start working?

Hi all, just a fundamental, basic grow question because I honestly have applied things a bunch of times now and have no idea if / when they will start working, or IF they even start working

edit - it’s 3 questions sorry

For example, if I start seeing pale-ing of any leaves in veg, or god forbid as keeps happening in flower, I race over to my Gaia Green All Purpose 4-4-4 or Power Bloom 2-8-4 and apply a generous amount - maybe even more generous than it calls for, and frantically water it in. As the following days go by the plant just seems to get worse and worse, which I am guessing, is because “by the time you see the problem, it’s too late”… and furthermore, or more importantly, because the dry amendments take time to be usable?

  1. But if it’s too late, what is the plan of attack at this too-late stage?

  2. How long even in a worst case scenario when the plant is unhappy going to take to start actually showing effect from something like the 4-4-4 top dressing?

  3. In these nightmare scenarios (like in flower) when the leaves are paling way too soon, like a month in, should I not only top-dress the dry amendment but also hit it with liquid nutes for the first X amount of days until transferring back to plain water and hoping the dry amendments take over?

Hopefully these all make sense, I feel like they’re important valid questions and I’d just like to hear from people who actually know

I think it’s especially important because I keep being tempted to “add more, add more, add more” when nothing is improving after application and I’m sure this is an extremely common pitfall many of us noobs encounter

THANK YOU ILGM FORUM :slight_smile:


depends on your medium. which is?


It is called Black Swallow Soil!

This exact product here:

KIS Mix Blended Soil | Black Swallow Living Soils, Brantford ON (

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Are you measuring your ph and ppm? Deficiencies and excess look similar, unless you’re measuring sounds like a guessing game

I grow organic and use Gaia Green as my base nutrients.

In my opinion, when it’s ’too late’ you have a tough decision to make.

Adding more dry amendments will take time to break down in your medium. How long depends on many factors, moisture, temperature, microbial populations - these factors all combine to affect the rate at which the amendments break down and become plant available. Colder pots/mediums especially slow down the process.

Side note - the dry amendments will break down without microbial life, but it takes time.

If your plants are showing deficiencies, I think it’s best to add some synthetic nutrients to rescue the plants. In my own grows I’ve seen a couple nitrogen deficiencies show up. I have a small packet of Nitrogen from Raw NPK, which is just dry nitrogen you mix into water. This gives an immediate nitrogen feed when your soil has run out.

If/when my plants look a big hungry or just slow growth, I water them with a mix of microbes, humic acid, fulvic acid, molasses, liquid kelp, and sometimes a bit of nitrogen. It’s not a regular treatment, just as needed.
Edit - I also immediately top dress before I water in the above mix.

If you really want to avoid adding synthetic nutrients, try watering in humic acid, fulvic acid, and or microbes. Those can all help make any nutrients in the medium available to the plants.

And I’m sure you know - the best practice is to actually avoid the situation. Either by top dressing more regularly, or growing the same size plants larger pots.


@Storm @Caligurl @GreenJewels @ChittyChittyBangin can help with the dry amendment question Growmie :love_you_gesture:


Highway Dust dude too :metal:t2::green_heart:



A few questions for you.

  1. What type of water are you using.
  2. How large and what type of container.
  3. Age of plant (s)
  4. What kind of lighting ?
  5. Average light on/off temps humidity?
  6. Pictures of plants would be helpful.
  7. Any perlite added to the soil ?

It takes dry amendments 1 to 2 weeks to breakdown nutes avail for the plant. I dont think youre having a deficiency, i think your ph is off just by description.

In soil during veg you want a soil ph of 6.0 to 6.5 and in flower 6.5 to 7.0

Alot of variables to consider when trying to diagnose a plant.


I agree with @ChittyChittyBangin… there are a lot of factors to consider.

I use dry amendments but they are specifically designed to break down quickly (ie Fox Farms Dry amendments). Other amendments like bone meal, blood meal, oyster shell, etc, won’t break down and be readily available to your plant.

If I see something that needs immediate attention, I prefer a foliar feeding. It goes right to the plant and no need for the roots to take them in. Think if you have root problems (like root rot, bad soil ph, etc), no matter what you feed them, the roots won’t take in the nutrients.


Auto or photo? Work on the life exclusivly now. Since ammended so much no more food. Lets get whats there broken down fast and good roots/life health. Typically with dry ammendments follow directions. Supplements have been adjusted for in the nutes. Extra snakeoil doesnt help. Flushing now might help but I typically ride them out till stabilize. Results with weak soil can take a week or 2. Strong healthy soil breaks the nutes down fast. 3-5 days at times for me. If says ammend 5 gal with such and such amount that is all you need to do. Foliar spray any calmag or silica you use. Until it dies keep hope. Especially photo. They ride through and recover. Auto can get pretty ugly and still produce good flower. Less is more with your topdressing. Ph is important but once life is strong the range widens considerably.

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I agree. Get that soil activity up then enzymes, microbes and fungal networks can break things down faster. No need to add more. I use fresh ground 6 row malted barley in topdressings for the high enzyme content which helps break down organic matter faster. Some things also break down faster than others. There are ways to add a quicker boost when needed. When in flower, Langbeinite ground up fine and stirred well in warm water will dissolve and provide potassium magnesium and sulfur. In veg make a tea with worm castings to increase the microbial activity and for a quick nitrogen boost. Compost teas are great too and can be taylord to specific plant needs. There are mycorrhizal products like mammoth p or rootwise’s biophos to help with the plants phosphorus uptake. Many things can be foliar fed in veg. I dont advise spraying flowers.

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@frozen ,
I concur with the above comments.
A pH tester will be your main tool in growing cannabis. It wants a slightly acidic soil to thrive. Get out of range and the plant cannot uptake things like Nitrogen and so it suffers no matter how much food you give it.
Let us know how things are doing and we all will help.

Hi GardenDan I have a question regarding Gaia green if you don’t mind helping me out. I just added my auto flower to my coco canna June 17th. I topped dress with Gaia green on the 21st.

I was planning on mixing the Gaia green with my canna coco before planting but my supplies didn’t get here for a few days later.

On June 21st I top dressed with the recommended amount per gallon.

I just recently bought the AC infinity self watering fabric pot base beings I’m gonna be going away for work for a week or two. I was wondering how I’m suppose to feed with the Gaia green amendments if I have to top dress. The self watering pot obviously wick up from the bottom.

I know it’s probably a stupid question but this is my first time growing and still in desperate need of learning.

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Just making sure I understand correctly: -You planted into pure canna coco - nothing else added.
-Then you planted your autos. Seeds or transplanted?
-then you top dressed with Gaia green

I think there’s a fairly high risk of this not going too well in the early stages. My guess, as I’ve never done or seen this set up, is the top dressing won’t be enough - mainly because it’s not physically located in the soil where early roots will need nutrients.

If there is any way for you to mix in more GG below the top dressing, I think that will help a lot. Even around the edges of the pot if you can. The young plants will have roots that need to develop and get up to the top layer of soil before they find nutrients. Again my guess is in early stages the plant will seem small, as a lot of energy will goes towards root development. Likely above-ground growth catches up later, but I honestly don’t know.

The GG will break down over time, and this requires moisture. While you’re home, I would hand water from the top, to help encourage breakdown of the GG and to help it get pushed further down into the pot.

While you’re away, I think another risk here is the GG from the top dressing in the top layer will dry out, and not break down fast enough, and nutrients won’t be available for the plants. But you can manage this with a mulch layer. I would put a good layer of mulch down, so the layer of top-dressed coco always stays moist. I would put down plain cardbo ard, then add a layer of mulch - hay, straw, rice hulls, leaf litter. Anything to prevent evaporation from the top layer.

For normal feeding, it’s fine to be away for a week or two (as long as you don’t run out of water). The GG top dress only needs to happen every 2-3 weeks. I’ve definitely gone 4 weeks and had no issues - I just tend to top dress more.

To be clear - I think this can work. Hand water from the top while you can. Add more GG, and try to mix it as far down into the pot as you can, without hurting the plant. If you’re still waiting for seeds to germinate, I would wait until they sprout. Because wouldn’t want to mix around the coco and accidentally kill the sprouting seed or bury it too deep. Use a mulch layer to keep the top of the coco moist, if it’s going to dry out.

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I mixed in canna coco 70% and 30-35% perlite. I mixed it together real good and then put the seed in. At the time I was expecting both the seed to be ready and the Gaia green to arrive at the same time but ended up getting delayed. So I had to put the germinated seed/tap root into the coco beings I got called into work and had to make it quick. I put the seed/tap root in on June 17th.

June 19th the seedling peeked through and on June 21st I was able to top dress in the Gaia green. I’m on week 2 now and will post my result so far. My opinion I think it should be a little bit better but it’s my first time so I’m really unsure of thing right now. I will include the second one I have going as well that started before the auto. Not sure of that strain but I’m feeding that one foop nutrients.

While I am away my fiancé should be home and able to keep up the watering from the top. I go away July 15th roughly and I’m hoping the root zone would be established enough by then to use the self water base and able to get the nutrients from the top by light watering through the top ? And allow it to get a drink as need from the base. Or would it be best to just not use the base and allow it to be watered through the top. I’m just worried about over watering because I’m not to sure of the recommended amount per says.

Pictures were just taken. They’re in the night cycle right now. Currently run a sf1000 in a 2x2x5. 18/6 cycle

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At first I thought was the same plant. They both look good. The first one doesn’t look hungry, so it’s getting enough nutrients from the soil.

You can definitely mix more GG deeper into the soil around the edges. I would go about half way from the outer edge to the middle, so you don’t. Disturb the young roots. Mix gently.

The younger one likely one need much water for quite a while, since it’s such a big pot. Have the roots grow outwards and down.

For the second plant, keep doing what’s working. If you’re worried about the feeding/watering while you’re away, you could top dress with some GG as a back-up.

I’d get the self watering bases going soon. Help train the roots to grow down and start drinking from the bottom. It’s such a good back-up while you’re away.

Start measuring how much water you’re giving the second plant. That way you can tell her how much to water while you’re away. At least that won’t lead to overwatering, and then the ACI base lets the plant drink the difference in what it needs.

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Thank you for all the insight ! I currently set up the bases yesterday. I put plain water in with the auto ( plant 2 ) I gave 500 ml of water today around 10am. I usually let it go for about 2-3 days or until the coco starts to look dry on top. I keep the water near the edges of the pot and not near the plant itself.

For plant 1 on the 26th I asked my finance to feed the plant and to use the gallon jug I had already made up for the plant. Not remembering she doesn’t really know much and she gave it the whole 1 gallon of week 2 nutes. I instantly took readings of the run off and thankfully the run off was 6.2 and a ppm level of about 900. Which I figured was okay. Yesterday the 28th I made another week 2 gallon and put it in the bottom of the base beings it typically took about 4 days in between it getting dry. I did some reading and it said that it could be done so I gave it a shot. Since then no watering from the top of the “plant 1”

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What he said…. Bigger pots next time, they leave room for error
To answer your question IMO atleast a week and a half to 2 weeks and by that time they are really suffering.
Noticing a something early…. Really early is key with dry amendments. But something from a farm would help pretty quickly…. Chicken poo, rabbit poo that type of thing will bring them around fast

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Looks like you’re well on track! Keep posting updates.

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Hey garden Dan, question if you don’t mind answering… I am wondering if the temp, RH and VPD is within range. I am currently in a 2x2x5 tent from spider-farmer. I will post pics below of my readings.

I also did as what I was told and I mixed in from the outside of the pot into the middle being very gentle mixing in the fert. I also gave it a good watering to get the Gaia down a little bit farther into the pot. I’m gonna be in panic for a few days wondering if I drowned her but I pretty much let my cousin do it being he been doing it for a little bit longer then me. Thank you in advanced!