Yellow leaves, but can't figure out the cause!

Here is a photo of my friend's plant. It was germinated in a peat pellet and then transplanted to a high quality soil, Plagron Lightmix. Sometime after it started to develop yellowing. Someone has said it could have been caused by the light burning it through water mist being sprayed over the plant, but I'm not so sure. What do you think?

I have no idea what your problem is but my guess would be your ph is off and your having nutirent lock or to much nutrient.

Do you know what your pH is on your run off?
What type of soil is that?
How old is the plant?
are you giving any added nutrients?

Chickadie said:

Do you know what your pH is on your run off?
What type of soil is that?
How old is the plant?
are you giving any added nutrients?

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I'm not 100% sure how old the plant is but I think it's a few weeks old.

The soil is the best you can get in the UK and the pH is usually between 5.5 and 6.5. My friend has an electronic pH meter (see photo). How would he measure the pH or the run off using this? Does he just water it, collect the water that collects at the bottom and measure the pH of that using the meter?

When he transplanted it into the soil he started to use a weak propagation nutrient (http://www.greenshorticulture.co.uk/Propagation-23/Propagation-Nutrients-302/Formulex-512.asp)

Maybe he should stop using this?

You know that other post you have about the wilting plant? That is what happens first when over watering. This is what happens next. Ease off watering so often and everything should be okay.

Excellent! That's a relief. I can now tell my mate what NOT to do! Thanks.

Artificial emotion said:

I'm not 100% sure how old the plant is but I think it's a few weeks old.

The soil is the best you can get in the UK and the pH is usually between 5.5 and 6.5. My friend has an electronic pH meter (see photo). How would he measure the pH or the run off using this? Does he just water it, collect the water that collects at the bottom and measure the pH of that using the meter?

When he transplanted it into the soil he started to use a weak propagation nutrient (http://www.greenshorticulture.co.uk/Propagation-23/Propagation-Nutrients-302/Formulex-512.asp)

Maybe he should stop using this?

Click to expand...

Okay - yes, just collect the water at the bottom, and pH that using that runoff water. I recommend watering with a pH of 6.5 - 6.8. But you want your runoff between 6.5 - 6.8, so you may need to adjust the pH going in depending on your soil.

Most soils contain enough nutrients for 3-4 weeks (sometimes more) and you're probably just burning the plant a bit -- although, burn usually shows some browning on the edges which your plants aren't displaying... which means that your pH may be creating a lockout (where the nutrients are unable to be absorbed).

The soil looks VERY short on perlite and/or vermiculate which is necessary for proper aeration. The roots require access to fresh air... if/when you transplant again (or with your next plants) I would recommend using about 40% vermiculate or perlite (or a mixture) and 60% of whatever soil you are using.

How often are the plants being watered? (someone mentioned over watering)

try to trans plant into large pots deep pots are best.Add perlite to ur soil and gravel at bottom of pot help drainage. And of course i'm a firm believer in bat gauno and worm castings but casting are big money. BAT G IS ABOUT $7 US.And looks like those things are over watered let top of soil dry before watering 2in down soil should still be moist a little bit. And if it was light burn the light would have to very hot and the leaf would be burnt what lite are u using mh,cfl,led. Oh good luck with that grow.

Cow Tea said:

You know that other post you have about the wilting plant? That is what happens first when over watering. This is what happens next. Ease off watering so often and everything should be okay.

Click to expand...

+1 here!
No worries yet, just be patient for now.