Possible nitrogen deficincy during flowering?

Hey everyone. My first grow is one month into flowering. I’m starting to notice that a number of fan leaves lower on the plant have begun to yellow, darkening around the main leaf veins, twisting of leaves, and eventually drying up. The leaves on the top of the canopy seem fine though.

My hunch is that is is a nitrogen deficiency, but was hoping to get some input from others too.

Growing in soil with Emerald Harvest nutrients. I water every day, but feed full strength nutrients every other watering. I’m thinking about increasing nutrients to half strength on the water only days.

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It’s normal for the lower leaves to yellow and fall off as the plant matures. Is the rest of the plant healthy? It’s not possible to assess a plant’s health with pics of a couple of leaves.


Exactly. Normally the larger older fans yellow first when its N deficiency. Those look like lower leaves that have done their jobs and are of no use to the plant anymore.

Full body photos would confirm or deny

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Thanks for the replies. The yellowing seems to be entirely on the lower leaves.

Here’s a full shot of the plant. Don’t judge me for the shape. :sweat_smile: I started growing this seed I found in dispensary weed without knowing anything about LST and topping, so here we are.

All the leaves showing these symptoms were below the trellis net.

Yup below the net, no big deal


Awesome. So it doesn’t seem necessary to up the nutes at this stage @PurpNGold74? Don’t want to overreact and burn the plant.

Are you aware of the runoff ppms?

If not, what kind of soil? And have u given anything?

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I don’t have the gear to measure PPMs yet unfortunately.

The soil I used is this garbage Kellogg’s organic raised bed soil that came with free unlimited gnats from the hardware store. :neutral_face:

I didn’t add anything to the soil other than feeding the liquid Emerald Harvest nutes about a couple months after planting the germinated seed in the soil (I had no idea what I was doing really). The plant growth was extremely stunted when growing in the soil only.

Once I got a grow tent and better light, improved some environmental issues, and started feeding with nutes, the plant bounced back and started having massive vegetative growth. I flipped to flowering a couple weeks after that.




They’ve taken over my entire home. I now have a dedicated 5 gallon bucket to soak mosquito dunks. smh


That bites! Frigging gnats are irritating as all outdoors. Food Grade DE seemd to get rid of them (helping hand at least).

Id definitely want a runoff number before advising to feed or nah. How about pH?

Cheapo ppm pens work like a champ. PH is where u wanna invest a bit more…


I’ll ph a runoff sample and report back.

My next run is going to be with coco and ILGM seeds, so definitely will look into PPM pens and upgrading from my cheap Hanna ph meter.

Will checkout the DE tip. I think I safely can rule out the perlite method as an effective gnat treatment.

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@PurpNGold74 Got my hands on an EC pen, and did some quick measurements:

Dechlorinated tap water before nutes: 0.3
Water + nutes: 2.3
Runoff: 4.3

To add some context, the runoff was collected from a drip tray that I haven’t been able to remove and clean since installing the trellis, so I think there’s a decent amount of build up from run off drying and leaving behind salts. I do try to collect most the runoff from the tray after watering with a big syringe. There’s definitely some material from the soil that also seems to get washed off with each watering and has strained my fabric pot.

Greatly appreciate any input you might have.

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I did ph and ec readings on a water only day too:

Tap water: 7.2 ph and 0.3 ec
Run off: 7 ph and 2.4 ec

Is that runoff still in the salty drip tray? U may want to get another tray to get a more exact runoff

2.3 is a decent runoff all the same though. Feeding at half strength (and proper pH!) should be just fine

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Appreciate all your help man.

Trying to get someone to help me swap out the trays, and will report back.

Basically, every watering/feeding I remove any remaining water in the tray with a syringe, but a small amount gets left behind, and I think that definitely has built up some salts.

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Yo what you think about this ? The ph has been at 6.2 ! I was thinking it’s a nitrogen deficiency but I’m lost atm

For what it’s worth, I think the issues I was noticing were possibly caused by scale insects. I noticed these bastards when watering one day. I suspect the yellowing and dying leaves on my plant were because of these sapping the nutrients out of the stem. Still an ongoing issue for me. :unamused:

I started noticing burn when I uped the nutes to from every other day to full strength every other day and half strength on others so I pulled back to every other day.

I did have issues with the top leaves getting lighter kind of similar to this earlier in the grow because of air circulation issues.

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Can you get a closeup of your leaves?