Cannabis plants are resilient.
They grow just fine without any nutrients. They will even yield some buds.
But if you want to maximize yields and get the kind of monstrous buds you see in photos from professional growers, you need to use nutrients.
And you need to use them correctly.
Over or underfeeding will impact yields and can even kill your plants. That is why you need to now how often you should give your plants nutrients. Let’s find out.
Contents
How Often Should I Give My Plants Nutrients?
There is no hard and fast answer. It simply depends on far too many factors (see below). But there is an easy answer to get you started: begin by following the nutrient schedule that comes with your nutrients.
Watch your plants closely and adjust as needed (more on this below as well).
But don’t follow the amount the schedule recommends.
Nutrient companies obviously benefit if you run through your supply faster and have to buy more. for that reason, their recommendations are generally higher than necessary.
We recommend starting with half of the recommended amount and adjusting up from there.
As for how often to feed your cannabis plants nutrients, the schedules are always on a weekly basis. So you can feed the entire amount once per weed or break it up over multiple waterings. Which brings us to another common question.
Should I Use Nutrients Every Time I Water?
This depends on a number of things, most of all the pot size. Larger pots do not need watering as often, so you may only water your plants once a week, or perhaps even once every two weeks. In that case, you obviously feed every time you water.
But in smaller pots, you may need to water several times a week. What do you do then?
Some people still recommend adding nutrients to the water every time you water your plants. They say a consistent supply of nutrients is better than giving a lot in one watering and none the next.
This actually makes a lot of sense, but it’s also more trouble and not something I usually recommend as a result. You would have to know how much water you will provide each week and divide up the weekly nutrients so that each watering contains an equal amount.
Obviously you don’t have to be exact, but it’s still more work than simply providing the full amount in one watering. I doubt whatever benefit you get is worth the extra trouble.
A good alternative could be to split the nutrients up over two waterings, with the second mid-week. Then give plain water the rest of the week, whenever the plants need it.
You may have come across suggestions like “feed, water, water, feed, water, water” or some variation. This simply means to provide nutrients and then water twice without them. Since the amount of time between watering can vary, this method could potentially lead to problems.
Bottom line: just keep it simple. Feed the plants once or twice (with half the amount of nutrients each time) a week and give plain water the rest of the time.
As you near harvest, most growers recommend withholding water altogether. This causes the plant stress and it responds by putting all of its resources toward bud growth, resulting in larger and more potent buds.
When should you stop watering before harvest? This varies, but generally from 1 week to 3 days before harvest. The ideal time depends on the strain, but any time within this range will result in better buds.
How Often To Add Nutes During Flowering
The answer to this common question is the same as above: follow the nutrient schedule. That generally means feeding once a week, but you can break down the weekly amount over multiple feedings, if you are using smaller pots that need water multiple times a week. I wouldn’t go more than two or three, though. Keep it simple.
The last few feeds before harvest should be just water, to flush the nutrients out of the buds before harvesting. Buds full of nutrients do not taste as good.
The nutrient schedule provided by your nutrient brand should have this flushing period on it. The best water for cannabis flushing is pure and neutral. If you are not sure how to flush cannabis plants, read that article.
Factors Affecting How Often To Feed Marijuana Plants
As mentioned above, a lot of different factors determine how often you will need to feed your weed plants. We are going to take a look at the most important ones here, starting with the growth stage.
Stage Of Growth
Marijuana plants have vastly different nutrient requirements, depending on their current stage of growth. And the requirements do not just differ in the amounts of nutrients overall, but the amounts of individual nutrients as well.
You can probably guess that young plants require fewer nutrients than more mature ones. Seedlings won’t need feeding at all. Once they enter the vegetative stage, you want to start them on nutrients, gradually increasing the dosage throughout veg. They need a lot of nitrogen during this phase.
Once they enter the flowering stage, they need more potassium and less nitrogen. Keep increasing the amounts of nutrients until the very end of the bloom stage. At that point, you should cease all feeding and flush the plants with only water.
Some growers stop using nitrogen completely toward the end of flowering. But it is fine to keep giving them some. The choice is yours.
Grow Medium
The grow medium you are using has a large impact on the nutrient requirements. If you are growing in coco, nutrient requirements will be high, because this medium does not contain any nutrients of its own.
Soil, on the other hand, already contains nutrients, so you will need to feed your plants less. Some soils contain so many nutes that you won’t have to feed at all for the first few weeks.
If you are growing using hydroponics, you will need to be very exact with your nutrient ppm and continually monitor it to ensure a steady supply.
Types Of Nutrients
Different lines of nutrients have different concentrations. Obviously you will need to feed less often, if your nutrients are more concentrated, and vice versa. As mentioned, follow the nutrient schedule included with your nutes (but cut down on the recommended amounts).
You also have the option to choose between synthetic and organic fertilizers. Both have distinct advantages, but I always recommend synthetic for beginners, because they are easier to dose correctly.
Recognizing Nutrient-Related Problems
As mentioned, the recommendations given are only a guideline—a good starting point. You will need to adjust from there.
How do you know what to adjust?
Your plants will tell you. But you have to know how to read their language. Let’s take a look at some common nutrient-related issues and the signs your plants will exhibit to inform you of each one.
Nutrient Burn
Nutrient burn happens when the plants are getting too many nutrients. This either means you are overfeeding them, or there is a buildup in the medium.
Generally, you will first see darker green leaves, with tips that are yellowish and brownish. They will also bend upward. The marijuana plant stems may also turn purple or deep red.
If the problem is not rectified, the discoloration will expand until there is a halo of sorts around the normally colored center of the leaf. Eventually, the leaves will twist out of shape.
In flowering, the calyxes and the sugar leaves might turn yellow and then shrink fast. You can prevent nutrient burn by starting with fewer nutrients than recommended and increasing very gradually. Keep track of everything.
If your plants are already suffering from nutrient burn, flush them with pH neutral water for a week and then begin feeding again. Feed much lower amounts than before and increase gradually.
Nutrient Deficiency
Causes of nutrient deficiency are underfeeding and nutrient lockout. General signs of a deficiency are dry leaves that begin turning yellow, brown or rust colored. Stems also get discolored.
You can find more specific symptoms for individual macro and micro nutrients in our detailed nutrient deficiency chart for cannabis. Finally, we have an entire article on potassium deficiency in weed plants here.
To treat a nutrient deficiency, you can’t simply feed more nutrients. If the cause of the deficiency is a lockout, increasing the amount would actually make things far worse. So you first need to determine if you have a nutrient lockout on your hands. If you do not, go ahead and increase nutrient levels.
Nutrient Lockout
Nutrient lockout means that something is prevented your plant from absorbing one, or more, nutrients. It can be a pH imbalance or a buildup of nutrients around the roots.
Too much of one nutrient can hinder the absorption of another. In terms of pH, each nutrient is best absorbed within a specific pH range. Luckily, there is overlap, so that all nutrients are absorbed well at a pH of 6.8 in soil and 5.8 for hydro and other soil-less media.
To fix either cause of a nutrient lockout, you need to flush with pH neutral water. And establish the correct pH level for nutrient absorption. Once you have achieved that, you can begin feeding again. You should also read my article on understanding and preventing nutrient lockout.
How Often To Feed Marijuana Plants: Final Thoughts
The frequency of feeding is not as important as the amount. You can feed more often, but you need to reduce the amount you feed each time. Or you can reducing the number of feedings, but you’ll need to increase the amount.
The overall amount depends on a lot of factors. your best bet is to take the amount suggested on the feeding schedule that is included with your nutrients and cut it in half.
Begin with that amount and gradually increase it, while monitoring your plants closely. They will let you know when you have exceeded the amount they want and then you’ll know the ideal level. Read all about growing cannabis here.
Raquale Starr says
Geat, informative information. Even “old” growers can learn something new or better ways to do something. Kudos, kudos, kudos!!!🤗🤗
joe says
full nutes for 1st and 2nd feed..water for 3rd feed ?works for me every time( i am an experienced grower)
PurpleHAZE says
Hahaha wash that Coco once every 2-3 deppending on the run off of the EC reaches the LEVEL { 0.5 ( DEPPENDING ON YOUR WATER OR USING A RO I do.
Please flush the plants 5 mins at time several time wait 5 mins then again (temp,pH,) salts are a cunt to wash out ( right temp and pH RO is a bonus )then Feed them with a lite blend of great white , recharge and Monmouth p..and biothrive 1/4 of the suggested doasge for all and once again make sure your ph is adjust. I do it the night before (don’t feed the for 12 housz
Till the lights come on again so .make sure you flush at lights off .Now it’s time for worpdrive : now we push the feed over your last feed concentrate and crank as much lite as possible I use a mix of advanced and canna but decently get you self AN carbo load two table spoons each blackstap molasses , corn syrup and carbo load make sure you mix it all up in warm water before pouring it the rezs . Up to you wish I had some one share the love before I bought all the junk from GH H&G Aww, advanced is the MJ and then cenna to save a little $ STILL WORTHY 🙌 HAHAHAHA POUND DIFFERENCEs<= 3*600hps handmedown world war 2 EQUIPMENT SUPER*LOMEN*HAZR = JUST UNDER 5 6V & 9
Try don't try iv done my part p.S OG SEED STRAINS DO WAY BETTER… AK WW NL SSH CK
Glenn says
You sound very educated. I’m still new to growing. It’s my first run. I need advice. My email is glemon79@gmail.com
I would appreciate your time
Greg says
You have put alot of time an thought into your feeding sounds like it works well
George says
Great info!!!
Any chance you can email me it
maddenbros1@gmail.com
Thanks brother
Anonymous says
So, ,you give them nutes from the star thru veg and then just water from flowering on!Dies that not affect yield!Sorry for the daft question,it’s my first time!👌🏻
Peter says
thats the biggest crap i heard!!!!! in flower they need extra PK!!!!!!! i always add some booster and never had a problem and ladies are happy!! always!!!!! i can imagine how yield must looks like without nutrients and specially in flower!!!!! hahahaha
Anonymous says
Hi my plants are about 1 ft high and now growing bushy but not tall and the are 5 weeks old any idea
peter says
it looks like its indica strain or indica dominant! thats nothing wrong with it but i would need more info about it !!! i grow indicas or indica dominants only-hybrids cos they have shorter flowering time
Luke says
Do you start nutes from seed?
Steven says
No, start during vegging.
Wayne says
How do I know when my girls are starting veggie stage
Mason says
Your plant will have 2 to 3 pairs of fan leaves. If you’re starting out in small containers for the seeds to sprout in, transplant them into their second or final growing container when the fan leaves are as wide as the container itself. The roots will be a little further away from the inner walls of the container making it safer to transplant at that time. Later than that will potential affect the roots and lead to probs like stunted growth for example.
Happy growing 👊
All the way from SA…
PJ says
Good information very helpful. Thanks.
DW says
Great article. For autoflowers I water daily with a baster. I water with nutrients a couple times a week. As much as possible, if I see a nutrient burn I scale it back. I use very little to no veg nutrients after blooming stage starts. Just bloom nutrients. – experienced grower
Mister G says
If I do not know the lineage of my strain how will I know when my buds are ready to harvest?
Steven says
This article covers how you can tell when your plants are ready for harvest (the last section of the article): http://growlightinfo.com/best-way-to-grow-weed-indoors/
Baxter J Wade jr says
I’ve been growing for a few years now (outdoors). This is my first year using a few auto flowering seeds. They are lacking in flower size.Do I increase the npk ratio. Right now I’m at 4-7-10. Any info is greatly appreciated. Thanks
Anonymous says
Yes add in supplements higher in p and k and a lil lower side of nitrogen then increase dosage slowly till last 4 weeks and slowly go back to the original dosage when flowering started last week or so before you cut and hang em out to dry run a flushant or at least pure water through em walah! Like magic!
Anonymous says
Started growing(outdoors) June and didn’t add nutes to my plant till vegging period but It was because I noticed burns and yellow colored leaves. I wasn’t sure if it was under feeding so I added nitrogen to it but still on the lookout if it’s going to be potent and healthy maybe flowering week I’ll feed it potassium and see how it goes
Stephan says
Hi everyone ive started a week ago my first indoor grow in a bathroom we dont use now. i have a 400w full spectrum led and ive started 50 cm away from the plant. after 3 days ive realized 1 plant go yellow so ive moved it up to 77cm and it looks good so far.. im on day 5 and got a fertilizer with the following stuff. will it work for my cannabis plants.
Nitrogen 5% Potash 5% Magnesium 0.3%
Phosphate 4% Sulphur 2.2% Boron 200 ppm
Copper 125 ppm Iron 250 ppm
Maganese 200 ppm Molybdenum 10 ppm
I also got one that is only Nitrogen Phosphate Potash and Sulphur… please i need as much advice possible. Ive plant alot outdoor by doing nothing extra to the plant but want to step up in the growing. i do gave 4 plants under the light.
Jamie says
Hey I started 8 of my plants July 1 I know that’s really late I was hoping snow would hold out a while this year since we didint get snow till dec last year. Anyways my question is can I finish my outdoor plants indoors if absolutely nessasary or am I screwd any help on this would be greatly appreciated. Thanks jay.
Anonymous says
I Started 4th f July last year (put the ladies in soil,outdoors). I got n excellent yield Oct 20ish👍
Jamie says
Another question. I have 5 train wreck auto flowers planted now there already started flowering but one of them I made the mistake of clipping some of the leafs before it started flowering . So my question is will those leafs grow back or did I wreck that plants growth cycle . I. Can provide pictures if needed
Anonymous says
Trim before flowering is always recommended. It sounds like you did this so you should be fine!
A says
I cut off bags of leaves once a week , plants can handle a lot. Once a branch comes in from the crook of the leaf I cut off the leaf to improve light penitration and air flow. Look up lolly poping on you tube, and look up topping , supercroping and low stress training which Is tying branches down to spread the canopy.
Chris M says
Using 1000 watt Gavita LED, 7 gal pro-mix soil. Doing a run with Emerald Harvest Nutrients Line. The suggestions on bottles and nutrients schedule do not say if it’s every watering or total per week numbers. For instance for both Bloom A and Bloom B it says 5ml per gal. Is that every watering or is that per week totals? I water every three days or so, so that’s a huge difference (5ml total vs 10 ml total per week). In general, with nutrient line schedules, are they per week or per watering schedules?
Keith says
My buds turned to like a dust state and never could find out why, any thoughts
Fabian Ceballos says
if my plants arent close to harvest and i been following the nurtients chart and im in my 7th week if it doesnt bud more by weed 9 then do i just add more bloom for a couple more weeks?
Keith says
Hello, it’s my first time growing indoors, i had some problems of course plants got stunted and all, now they are back on track in there mid-veg , i did some slow stress training and turned up the light, leaves started to get droopy at the canopy, I’m using Viparspectra XS4000 in my 4*3’ tent hanged at 40” hight it was dimmed at 25 percent brightness, leaves got droopy when I turned it up to around 35-40 brightness same hight(40”), I’m confused light’s manufacture says to turn the brightness up to 60 percent for seedlings and young vegs at 30-34” hight!, any ideas about what’s going on?, all i can think of is that this strain doesn’t like to get much light!
PETER says
Hi man there can be few things… i would first checked the PH of the soil cos sometimes its not right , than what nuts are you using??? Whats your temp. and humiditty????if the ph is ok than it looks like some nuts deficiency or so…
joseph says
Hi Guys, I have a question related to DW (5 gal. container)
I need to know if I should, replace the whole body of water with new nutrients every week or just add whatever has been consume with a nutrients in the indicate ratio per gallon ,.
Thank you in advance for the advice
JB
Peter says
hi there
i would change water every week or so cos fresh water and nuts too and of course check ppm and ph but thats me im sure somebody else it would do it bit differently…
Matt Benes says
Help! First time grower. I have two outdoor Acapulco Golds that are about 4 weeks into flowering. Both plants are over 9′ tall. I’m starting to get some yellow leaves at the top of both plants. Thoughts?