General yellowing of plants

[VaporMan]

The leaves are getting yellow. It appears to effect the entire plant(lower leaves are the most yellow). I have tried Fox Farms Grow Big, 1/4 tsp per ga. but no improvement. Tried foliage feeding but no improvement noted. The plants look wilted, but soil is moist. I do not think my problem is root rot.

Thanks,
VM

 

[mared juwan]

How old are your plants exactly? If increasing nutes didn't work and you are experiencing yellowing and drooping then overwatering or a ph imbalance comes to mind.

 

[heathaa]

you gotta give us more to go on. soil? water?ph? nutes? lights? flowering?

 

[VTGOLD@420]

what kind of lighting do you use? If your light isnt penetrating the top canopy the bottom leaves will yellow, Make sure your not over watering. Let the soil dry out quite a bit itll make for a strong plant

 

[VaporMan]

The plants are about 3wks old. I have them under a 400w hps. I am using Black Magic potting soil in 1-5ga. pots. The light is on 18-6.

 

[mared juwan]

OK, most important thing you can do is lift up your pot every day and feel how the weight changes when it is wet or dry. A pot that has just been watered will be very heavy. You want to let it get pretty dry before soaking it again. It should feel almost empty because dry soil weighs next to nothing. When you do water, flood the pot very well, because gravity will work for you to push out the old stale water and pull in fresh oxygen. Are you monitoring/adjusting the ph of your feed water?

 

[VaporMan]

OK, most important thing you can do is lift up your pot every day and feel how the weight changes when it is wet or dry. A pot that has just been watered will be very heavy. You want to let it get pretty dry before soaking it again. It should feel almost empty because dry soil weighs next to nothing. When you do water, flood the pot very well, because gravity will work for you to push out the old stale water and pull in fresh oxygen. Are you monitoring/adjusting the ph of your feed water?

I have a ph meter on the way(ebay Hanna brand) is this a good meter? My pots are heavy with water, but the plants look as if they are under watered(droopy canopy) when I apply water, they pick up a bit. Could this be over watering or the wrong ph? The plants grew very quickly until they 'seemed to hit the wall"

 

[mared juwan]

If the pots are heavy and the soil is wet then more water won't fix the problem. The roots are actually drowning. They need air just as much as they need water. They probably look better for a short while after you water because there is a little bit of fresh oxygen in the water. But if you don't allow the soil to dry out and become aerated before flooding it again the recovery will be short term. The Hanna meters are good. I have the combo Temp/ph/ppm one. Depends how you are treating your water whether it could cause ph problem. 6.5 is ideal for soil but you're fine up to 7.5. Some tap water might be out of that range.

 

[VaporMan]

If the pots are heavy and the soil is wet then more water won't fix the problem. The roots are actually drowning. They need air just as much as they need water. They probably look better for a short while after you water because there is a little bit of fresh oxygen in the water. But if you don't allow the soil to dry out and become aerated before flooding it again the recovery will be short term. The Hanna meters are good. I have the combo Temp/ph/ppm one. Depends how you are treating your water whether it could cause ph problem. 6.5 is ideal for soil but you're fine up to 7.5. Some tap water might be out of that range.

So I should allow the pots to dry out? Any way to speed up the process? Will the plants recover if I let the pots dry out?

Thanks
VM

 

[OregonMeds]

Throw tons of light on them and let them get much hotter than you normally allow, that'll make them drink up water real fast. You can easily go 100f in your room without hurting them if they aren't so sick they're near death already or something. (which it sounds like they aren't)

 

[mared juwan]

I don't want to tell you 100% I know what the problem is because I don't even have a pic to go with but if you have been keeping your soil constantly wet then that would eventually become a problem so I imagine things should improve if you just keep lifting the pots and study how the plants change as the weight of the pot changes. They will droop when wet and then perk up as the pot dries a little. As you near the time for another watering they will begin to droop again.

 

[VaporMan]

Ok, I will stop watering until the pots feel light. But what is causing the plant to yellow? Is this related to the overwatering?

 

[Cap K]

Ok, I will stop watering until the pots feel light. But what is causing the plant to yellow? Is this related to the overwatering?

Sometimes yellowing is as a result of heat burn, but often yellowing leaves are seen late in the flowering stage when she is using all of her sugars and energy for bud production. In this case yellowing leaves are nothing to worry about. Also raising the temp is a good idea to force the plant to drink more quickly, but keep a watchful eye. As soon as you see that the soil has dried out lower your temps back to where you had it. As for letting the soil dry out between waterings, I employ the finger method. I stick my finger bout an inch into the dirt. If it's dry i water and if it aint i dont. I've been finding that there is no exact science to this . Sometimes she wants water every other day, sometimes every 2 or 3. Once you have rehabilitated your girl just keep a close eye on her and only give her what she needs when she needs it.

 

[Peter421]

Either your plants are having a pH problem (too acidic) or possibly your plants are just coming to age where the lower leaves have done their part for the plant. Usually for me, I'll start picking off leaves bottom to top.

 

[doobnVA]

Black Magic potting soil, eh? I'm using the same thing, and here's what I think... it stinks.

Put all my seedlings into it once they'd germinated. The stuff was so chunky and full of sticks and shit that I ended up having to sift it before using it. I accidentally dropped two of the seedlings on the way to the grow room, so I refilled those with a sphagnum/vermiculite mix. The ones in the sphag/verm are doing SO much better than the ones in the potting soil, even though I dropped them on the floor and was certain I'd killed them.

I've been using this soil to try and start a bunch of tomatoes, peppers, cukes, and herbs for the outdoor garden and not having much luck at all. I'm pretty sure it's the soil, because everything in the sphag/vermiculate mix does just fine.

What I did just now was transplant my babies into larger pots with more of the sphag/verm mix. Hopefully the ones that weren't doing as well will catch up now.

Anyway, that's just my two cents about Black Magic potting soil.

 

[Peter421]

Black Magic potting soil, eh? I'm using the same thing, and here's what I think... it stinks.

Put all my seedlings into it once they'd germinated. The stuff was so chunky and full of sticks and shit that I ended up having to sift it before using it. I accidentally dropped two of the seedlings on the way to the grow room, so I refilled those with a sphagnum/vermiculite mix. The ones in the sphag/verm are doing SO much better than the ones in the potting soil, even though I dropped them on the floor and was certain I'd killed them.

I've been using this soil to try and start a bunch of tomatoes, peppers, cukes, and herbs for the outdoor garden and not having much luck at all. I'm pretty sure it's the soil, because everything in the sphag/vermiculate mix does just fine.

What I did just now was transplant my babies into larger pots with more of the sphag/verm mix. Hopefully the ones that weren't doing as well will catch up now.

Anyway, that's just my two cents about Black Magic potting soil.

I also use Black Magic soil, I agree with all those stupid sticks and how the soil can get pretty packed and hard together. I usually do a 60%/35%/5% soil/perlite mix/guano and after that, the stuff gets pretty airy. But those bullshit sticks. WTF. I've had a germinating seed snap in half because of a stick I believe. Other than that, if you get that problem out of the way, Black Magic soil isn't TOO bad.

 

[VaporMan]

And here I thought Black Magic was the bomb! Next planting I will try Fox Farms potting mix. Any ideas about the general yellowing of the plants? I am leaving for town and will pickup a bottle of Cal-Mag to try later.

 

[doobnVA]

I also use Black Magic soil, I agree with all those stupid sticks and how the soil can get pretty packed and hard together. I usually do a 60%/35%/5% soil/perlite mix/guano and after that, the stuff gets pretty airy. But those bullshit sticks. WTF. I've had a germinating seed snap in half because of a stick I believe. Other than that, if you get that problem out of the way, Black Magic soil isn't TOO bad.

I dumped the rest of my bag of Black Magic (which I like to affectionately call "BM" or "shit" for short) in the yard. Had a few areas that were sunken in from tunneling moles, so I used it to raise those areas back up. I've seen a lot of crappy potting soil, but this crap has to be the worst. I'm glad for you that you've been successful using it, but I'm definitely not buying it again.

 

[Peter421]

I dumped the rest of my bag of Black Magic (which I like to affectionately call "BM" or "shit" for short) in the yard. Had a few areas that were sunken in from tunneling moles, so I used it to raise those areas back up. I've seen a lot of crappy potting soil, but this crap has to be the worst. I'm glad for you that you've been successful using it, but I'm definitely not buying it again.

Oh I'm not going to buy it again but since I have so much of it I'm better off just using it and making the best. I really don't know whats a good soil.. So I might just go soiless mix and control the nutrients by myself.

 

[ROBINBANKS]

Oh I'm not going to buy it again but since I have so much of it I'm better off just using it and making the best. I really don't know whats a good soil.. So I might just go soiless mix and control the nutrients by myself.

Not sure where you are or what you can get, but anything by canna will sort you out, also whatever you get just use water the first few weeks they'l get by just fine.
Canna pro soil mix.