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Need help diagnosing seedlings in coco

splicendice

New member
Hey there! New to growing, got a question about some seedlings. Larger ones are at day 18 from germination. I'm growing in Canna Coco, using their nutrient guidelines. RH around 25%, temp is around 74. Using LED lighting.

My problem is the leaves seem yellowed, dry, and curling. Is this due to underwatering? Or could it be from pH and/or EC problems? I give them about half a cupful every night and the soil is still pretty moist just before watering. I've included pictures from the last 3 days. Thanks for the help.

P.S. I'm still waiting for my pH and EC meters that are coming in the mail. Should be sometime tomorrow.
 

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Switcher56

Comfortably numb!
... you may want to start by raising your RH to 65% for veg. (the general consensus) How high is your light from your plants?
 

MrBungle

Active member
To me it looks like over watering and pH issues... how long were they above ground before you started noticing problems? when did you start using nutrients?
 
R

Rab.C

bro see when there small let them get a wet dry cycle till the build roots.then feed everyday
when they have roots too handle feed...all the best Rab.C
 

TanzanianMagic

Well-known member
Veteran
Hey there! New to growing, got a question about some seedlings. Larger ones are at day 18 from germination. I'm growing in Canna Coco, using their nutrient guidelines. RH around 25%, temp is around 74. Using LED lighting.

My problem is the leaves seem yellowed, dry, and curling. Is this due to underwatering? Or could it be from pH and/or EC problems? I give them about half a cupful every night and the soil is still pretty moist just before watering. I've included pictures from the last 3 days. Thanks for the help.

P.S. I'm still waiting for my pH and EC meters that are coming in the mail. Should be sometime tomorrow.
I agree that it's overwatering.

The plants are literally standing on a wet paper towel.

The thing to do is to feed them a 0.4 EC of bloom food, which is higher in P. And a little magnesium/epsom salt, which is what the plants rellay need - a big root system and magnesium for the leaves.

And then don't water/feed them every day. It's ok to let coco go dry. Especially if you've given them extra P for root growth.
 

TanzanianMagic

Well-known member
Veteran
Hey there! New to growing, got a question about some seedlings. Larger ones are at day 18 from germination. I'm growing in Canna Coco, using their nutrient guidelines. RH around 25%, temp is around 74. Using LED lighting.

My problem is the leaves seem yellowed, dry, and curling. Is this due to underwatering? Or could it be from pH and/or EC problems? I give them about half a cupful every night and the soil is still pretty moist just before watering. I've included pictures from the last 3 days. Thanks for the help.

P.S. I'm still waiting for my pH and EC meters that are coming in the mail. Should be sometime tomorrow.
I agree that it's overwatering.

The plants are literally standing on a wet paper towel.

The thing to do is to feed them a 0.4 EC of bloom food, which is higher in P. And a little magnesium/epsom salt, which is what the plants really need - a big root system and magnesium for the leaves.

And then don't water/feed them every day. It's ok to let coco go dry. Especially if you've given them extra P for root growth.

25% is very low, however the solution isn't to overwater the plants, you can have a plant tray with water standing nearby.

However the first priority of growing seedlings and clones is to put a big root system on them. That means you have the medium get dry and give them P for rootgrowth.

You should put a pH pen in unfiltered water for a day, so it can hydrate, before you callibrate it.
 

TanzanianMagic

Well-known member
Veteran
First time I've heard this. There's a rather sharp drop in pH as coco dries out past 'moist.' No?
I don't know if it drops the pH. However that, wilting, or any nutrient deficiencies are very easily remedied by watering/feeding again.

Letting the coco get dry (watch for wilting) allows a lot more air to get into medium. When you have a small pot and only one medium, there is either water or air present. Not letting enough air get into the medium also slows root growth. Also, when coco dries up, it gets looser, and gets easier for small roots to penetrate.

What I would try to do something about is the Relative Humidity, which at 25% is too low, at least indoors, and get it closer to 50%.

I should add, I don't add any perlite to the coco. I do have a perlite layer for drainage, just enough to cover the drainage holes.

Watering/feeding less frequently creates more stability for the plant. It also encourages the plant to send out roots to look for water and food.

And it works great. When you get a bigger root system, the plant is more resilient, can take bigger swings in humidity, and takes up more nutrients, to you have much less frequent nutrient deficiencies.
 
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splicendice

New member
The light is about 2.5 feet from the plants. The problems started immediately when I was underwatering them. I started using nutrients as soon as they went into coco. Lol "the plants are literally standing on a wet paper towel." They are, however, this was just after watering and as any coco grower says, you need 10-30% runoff, so that isn't unusual. Standing water doesn't raise RH in the growbox. The ventilation is too good. pH meter is coming in the mail tomorrow, so I can finally test what I've been giving them.

Thanks for all the replies folks, much appreciated.
 

TanzanianMagic

Well-known member
Veteran
The light is about 2.5 feet from the plants. The problems started immediately when I was underwatering them. I started using nutrients as soon as they went into coco. Lol "the plants are literally standing on a wet paper towel." They are, however, this was just after watering and as any coco grower says, you need 10-30% runoff, so that isn't unusual.
If you put a large saucer with water in it next to the plants, the evaporation will collect on the underside of the leaves. It will not raise the RH in the entire grow box, however it is likely just enough to slow rate of transpiration of the plants.

The problem isn't underwatering. The problem is fast transpiration of water from the plants' leaves, because of the low RH.

The roots of these young plants can pump up only so much moisture, and they need air to breathe.

When you take care of the plant's environment (RH, temps, ventilation) first, and the nutrients second, a lot of things will fall in place.
 

weedobix

Well-known member
ICMag Donor
Veteran
Personally I prefer to use a proper veg feed like hesi tnt and then canna for flowering. Use a wet and dry cycle like soil feeding until they completely root out their final pots. Seeds only want a very low EC, they will get by on water alone for quite while even in coco
 

MrBungle

Active member
Feeding the flower nutes to a seedling is a way to de-stress the little one.... the additional P in the flower feed encourages root growth and allows the plant to repair itself.. once the seedling is back on track resume with the veg feeding
 

splicendice

New member
You guys are all incredible. The support is really overwhelming, and it's nice to see people come together like this for strangers, especially nowadays.

I've measured pH, it's 6.55. I'll bring it down to around 5.9 after work tonight and start feeding them with that.

I'll take your advice Tanzanian in regards to the RH and I'll be back to let you guys know how it works out.

Someone in a different forum said it could be a Ca deficiency and to start adding CalMag to my Canna nutrients. What do you folks think of that?
 

Switcher56

Comfortably numb!
You guys are all incredible. The support is really overwhelming, and it's nice to see people come together like this for strangers, especially nowadays.

I've measured pH, it's 6.55. I'll bring it down to around 5.9 after work tonight and start feeding them with that.

I'll take your advice Tanzanian in regards to the RH and I'll be back to let you guys know how it works out.

Someone in a different forum said it could be a Ca deficiency and to start adding CalMag to my Canna nutrients. What do you folks think of that?
... baby steps :) IMHO there are far toooooo many individuals using Cal Mag as a culprit for other deficiencies. Look after the known, and let the plant dictate where you go next. :tiphat:
 

splicendice

New member
Hey everyone, just wanted to catch up with yall since everyone was so professional and contributed so much expertise. First off, I created a new batch of nutes and pH'd it to 5.8 and brought my EC to 1.6. I transplanted my oldest plants to bigger, 5 gal smart pots. Next, I began watering them less, about every 2-3 days instead of everyday. Finally, I put in 4 large round plates filled with water as a makeshift humidifier. This has brought my RH to around 35-45%. Daytime temperature is around 68-72 deg. Nighttime temperature is around 55-65 deg.

I posted a pic so you can see the change. Thanks for all the great advice folks!
 

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R

Rab.C

Hey everyone, just wanted to catch up with yall since everyone was so professional and contributed so much expertise. First off, I created a new batch of nutes and pH'd it to 5.8 and brought my EC to 1.6. I transplanted my oldest plants to bigger, 5 gal smart pots. Next, I began watering them less, about every 2-3 days instead of everyday. Finally, I put in 4 large round plates filled with water as a makeshift humidifier. This has brought my RH to around 35-45%. Daytime temperature is around 68-72 deg. Nighttime temperature is around 55-65 deg.

I posted a pic so you can see the change. Thanks for all the great advice folks!

splicendice your plants are looking great
 

TanzanianMagic

Well-known member
Veteran
Hey everyone, just wanted to catch up with yall since everyone was so professional and contributed so much expertise. First off, I created a new batch of nutes and pH'd it to 5.8 and brought my EC to 1.6. I transplanted my oldest plants to bigger, 5 gal smart pots. Next, I began watering them less, about every 2-3 days instead of everyday. Finally, I put in 4 large round plates filled with water as a makeshift humidifier. This has brought my RH to around 35-45%. Daytime temperature is around 68-72 deg. Nighttime temperature is around 55-65 deg.

I posted a pic so you can see the change. Thanks for all the great advice folks!
That's great and they've grown a lot. :)

However I would correct 2 more things, because you're still overfeeding/overloading the coco coir with too much nutrients, and the wrong nutrients.

First, the plants' roots need to grow a lot. Phosphorus is the stuff roots are made of. The water's EC plus 0.4 EC of bloom food is excellent. You can try high P/K food like PK 13/14, Atami B'cuzz, Ripen, etc. or an ordinary bloom food like Bio Sevia bloom, or your own bloom fertilizer will be fine.

Just feed that for a week, which will have a huge effect, especially in combination with the slightly drier medium.

1.6 EC of regular feed is too much without most of the medium having been colonized with roots, and has too much nitrogen in it.

Just add a little magnesium to keep the leaves happy, and keep the EC at an even 6.0 throughout the grow, and you won't go wrong.
 
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