Yellowing leaves on flowering plant



I have a pretty large bush growing from Bergman’s seeds and it is about mid-way though the second week of flowering. I am noticing more and more leaves turning yellow and falling off. At first it was around the bottom but now there are more up towards the top of the plant as well. The attached image shows the yellow leaves in various stages.

The plant is growing outside in a pot of dirt sitting inside a 1 meter square hydro tray filled with perlite. The tray and pot get automatically watered from the top every two hours during the day (a soaker hose is inside the top of the pot and the water flows through, back into the perlite, and drains back to the drum). The hydroponics water drum has a pH of 5.5 and the nutes have now been adjusted for flowering.

I understand that losing a few leaves is normal at this stage, but the loss seems to be increasing daily. It is highly likely that the pot is root-bound to hell because the plant itself is about 5 ft high and has a diameter greater than 1 meter. Previous grows using the same method have not had this particular problem however, and although they too became root bound in the pot the top watering method keeps them well hydrated.

I figure a good 8 weeks left before harvest at least, but at this rate of loss i’m not sure it’s going to make it! I would be grateful for any suggestions as to what to do about this problem.

Thank you! :slight_smile:


Definitely fill out a ticket.

For soil, that pH is too low. Also, if you’re using soil, you definitely don’t want to keep it constantly wet. Could be nute issues due to improper pH, or over-watering. If you’re growing in soil, you cannot use hydroponics methods/parameters.

I’m no expert, except at screwing up. I’ve been there and done that with overwatering, nute toxicity, and nute lockout. And it always gets me the first or second week into flowering. I’ve now learned to flush my plants before transitioning from grow to bloom nutes, and to check my soil pH & ec as well as my h2o.

Some experts in not screwing up with be along to help. :grinning: I just hope you can get this under control. Nothing more disappointing than spending months working hard, only to have major issues at the beginning of flowering.

Hoping you get the help you need!


Thanks! I am now leaning towards it possibly being a root bound problem.

Although the plant itself is in a dirt pot, it is being grown hydroponically outdoors as the pot itself is sitting in the hydro tray as basically just a holder, all the nutrients are coming from the hydroponics water drum with an automatic watering system. It’s a kind of hybrid system that has worked well over the previous 2 seasons. We have just added an air pump to the drum because, well, it can’t hurt.

It is going to be a major undertaking to re-pot into a bigger pot because it has already just about outgrown the bamboo frame around the system that supports full bird netting all around. I don;t mind doing it however, I just want to be sure it’s really the problem before undertaking such a task! :slight_smile:

A small jalapeno pepper plant growing in a smaller pot sitting under the bush has some yellow leaves too, but pulling it out I saw that the roots are white and healthy. If it is a pythium problem I would have thought it would infect the entire tray.


Yes, but soil acts differently than soilless systems. Adding water & nutes every few hours, as well as having a 5.5 pH is not good for a soil media. The roots are in soil and need to be treated as such.

I could very well be wrong about this, so don’t take my word for it. :grinning:


Thanks again! Okay update on the saga lol

We added the air pump and got the pH up to just over 6.1. I cut away the old bucket and the roots looked great - they were the right colour, no mushiness, no odour.

It was root-bound, but interestingly in this system the roots all gather in a thick layer around the outside perimeter of the pot. Thankfully there were no signs of root rot, which was my greatest fear. I then put the entire root ball into a larger pot and filled up the extra space with the perlite I removed from the tray to make room for the bigger pot.

I’m now hoping that giving the roots a little more breathing room, raising the pH, and adding the aerator to the system will keep it all going for the next few weeks until harvest.

Here’s the baby in her new pot. For scale the tray is 1m square.


Good looking plant


That is one heckuva plant, there! That girl definitely needs a lot of room for her roots. Wow!


thanks :smiley:

This is my 3rd season growing using this method and of course we refine it as we go along. This is I think the largest bush so far but the harvest will tell. cross fingers

Originally we were simply using a fill/drain method through the tray but decided that watering in this way was causing a buildup of salts in the dirt bucket. We switched to using the soaker hose coiled around the main stalk so this keeps it rinsed out. Next season I will definitely be starting with a larger bucket! :smiley:


I got this…lol


IT’S Phosphorus Deficiency.

Here is my pic. Do ya think they look the same…


Benefit: Phosphorus does a lot of things for the plant. One of the most important parts of Phosphorus is: It aids in root growth and influences the vigor of the plant and is
one of the most important elements in flowering as well helps to germinate seedlings.
Phosphorus is an essential plant nutrient, and since it is needed in large amounts, it is classified as a macronutrient. Phosphorus is a MAJOR important nutrient in the plants reproductive stages. Without this element the plants will have a lot of problems blooming without proper levels of Phosphorus.

When your plants are deficient in phosphorus, this can overall reduce the size of your plants. Not enough causes slow growth and causes the plant to become weak, to little amount of Phosphorus causes slow growths in leaves that may or majhy not drop off. The edges all around the leaves or half of the leaves can be brownish and work its way inwards a bit causing the part of the leaves to curl up in the air a bit. Fan leaves will show dark greenish/purplish and yellowish tones along with a dullish blue color to them. Sometimes the stems can be red, along with red petioles that can happen when having a Phosphorus deficiency. This isn’t a sure sure sign of you having one though, but can be a sign. Some strains just show the red petioles and stems from its genes.
So pretty much the overall dark green color with a purple, red, or blue tint to the fan leaves is a good sign of a Phosphorus deficiency. Having Cold weather (below 50F/10C) can make phosphorous absorption very troublesome for plants.
Many people get a Pho-phorus deficiency confused with a fungus problem because the ends of the leaves look like a fungus problem, But the damage occurs at the end of the leaves. side of the leaves and has a glass like feeling to it as if it had a ph problem. Parts affected by a phosphorus deficiency are: Older Leaves, Whole plant, Petioles.

Too much Phosphorus levels affect plant growth by suppressing the uptake of: Iron, potassium and Zinc, potentially causing deficiency symptoms of these nutrients to occur def in plants. A Zinc deficiency is most common under excessive phosphorus conditions,
As well as causing other nutrients to have absorption troubles like zinc and copper. Phosphorus fluctuates when concentrated and combined with calcium

Problems with Phosphorus being locked out by PH troubles
Cold wet soils, acid or very alkaline soils, compacted soil.


Phosphorus gets locked out of soil growing at p h levels of 4.0-5.5
Phosphorus is absorbed best in soil at a p h level of 6.0-7.5 (wouldn’t recommend having a p h of over 7.0 in soil) Anything out of the ranges listed will contribute to a Phosphorus deficiency.

Hydro and Soil less Mediums

Phosphorus gets locked out of Hydro and Soil less Mediums at ph levels of 6.0-8.5.
Phosphorus is absorbed best in Hydro and Soil less Mediums at ph levels of 4.0- 5.8. (Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Phosphorus Deficiency.

Solution to fixing a Phosphorus deficiency
Some deficiency during flowering is normal, but too much shouldn’t be tolerated. Any chemical or organic fertilizers that have Phosphorus in them will fix a Phosphorus deficiency. If you have a phosphorus deficiency you should use any N-P-K ratio that is over 5.Again Peters all purpose 20-20-20 is a good mix. Miracle grow Tomato plant food, Miracle grow All purpose plant food (Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) Other forms of phosphorus supplements are: Bone meal, which is gradual absorption, I suggest making it into a tea for faster use, where bone/blood meal is slow acting, but when made into a tea it works quicker! Fruit eating bat guano, which is fast absorption, Worm castings, which is gradual absorption, Fish meal, which is medium absorption, Soft Rock Phosphate, which is medium absorption, Jamaican or Indonesian Guano, which is fast absorption. Crab- shell, which is slow absorption. Tiger Bloom , which is fast absorption.

Here is a list of things to help fix a Phosphorus Deficiency.


Advanced nutrients Bloom (0-5-4)
Vita Bloom (0-7-5)
BC Bloom (1.1-4.4-7)
GH Flora Bloom (0-5-4)
GH Maxi Bloom (5-15-14)
GH Floranova Bloom (4-8-7)
Dyna-Gro Bloom (3-12-6)
Fox Farm Tiger Bloom (2-8-4)
Awsome Blossums


Dr. Hornby’s Iguana Juice Bloom (4-3-6)
Advanced Nutrients Mother Earth Bloom (.5-1.5-2)
Fox Farm Big Bloom (.01-.3-.7)
Earth Juice Bloom (0-3-1)
Pure Blend Bloom (2.5-2-5)
Pure Blend Pro Bloom (2.5-2-5)
Buddswell (0-7-0)
Sea Island Jamaican Bat Guano (1-10-0)
Indonesian Bat Guano (0-13-0)
Rainbow Mix Bloom (1-9-2)
Earth Juice Bloom (0-3-1)
BIO BLOOM (2-6-3.5)
AGE OLD BLOOM (5-10-5)

Any of these will cure your phosphorus deficiency. Affected leaves will not show recovery but new growth will appear normal.

Now if you added to much chemical ferts and or organics,( which is hard to burn your plants when using organics) You need to Flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.

Note: Blood Meal, Dried Blood, Guanos, Kelp Meal, Cotton Seed Meal, Peat Moss,
Sulfur and fish meal are all acidic and can bring your ph down, so if you add these please monitor your ph when using those.

Note: Bone Meal, Rock Phosphate, Wood Ashes pretty much all ashes, Shellfish Compost and Crab Meal are all alkaline and can make your ph go up, so if you add any of these please monitor your ph.


wow excellent information, thank you so much! <3

She has just finished her second week of flowering and I’m still seeing more leaves yellowing than I would like. Do you know how much leaf loss at this stage would be considered normal? The individual leaves that are affected seem to be yellowing overall. It’s not really confined to the edges, but some have developed like a large yellow spot right on the edge with the rest of the leaf still dark green. Mostly they just get lighter and lighter all over until full yellow and drop off,

I have switched over to flowering nutes a week or so ago but I will be sure to add more phosphorus as you have suggested and keep a close eye on the pH. OMG it’s like having a sick child I’m very concerned :frowning:

Thanks again! :slight_smile:



I made a photo of some of the leaves, is this phosphorus deficiency?

My current theory based on the information above is that the original dirt pot was too small for the size this grew into. The dirt is very compacted and the roots were all in a layer around the perimeter of the original pot, hence they were not able to uptake the phosphorus, even though we added extra P for the flowering stage.

The original root ball is now sitting in a larger pot which was then filled up around the edges with perlite. The roots are still on the outside of the original root ball, but now they have breathing room in the less dense perlite and hopefully this will allow for better uptake of the P. I’ve added more P to the drum and keeping the pH at about 6.



Ya sure is…here is my pic…do you think they look the same…I do



yes I am convinced! lol :wink: Hopefully making these changes will keep us gong another 6 weeks or so :smiley:


I checked the EC on this and it was near 8000, so at least part of the problem could have been some nute burn as well. After adding extra P I was still getting about 30 - 50 new leaves yellowing per day, so I basically reset everything, drained, cleaned, and refilled the drum with fresh water and restored the nutes according to Hoagland. The EC is now @ 3360 which seems more reasonable than 8000 :wink:

Every year is a learning experience, I’ve had to come post about some problem for the last 3 seasons lol :smiley: . I’m thankful for all the helpful advice from everyone here. :slight_smile: