I do have a reverse osmosis tap in my house that I could use water that goes through it but worried that it will be bad because I think that water goes through water softener first. It is very soft water and ph is 6, alkalinity is low, nitrate is 0, nitrite is 0. I have no idea what all these mean but I do think that you don't want to use water that goes through a water softer. That's what I have read anyways

You dont say how big the plants are.

I asked the same question in an earlier post, but at the time my petunias that were yellowing were tiny (maybe 1 or 2 sets of true leaves, less than a nickel size in diameter). Dave (main seedling guru on this forum) suggested that it was overwatering. It wasnt so much that I was watering them to often, they were just not drying out quickly enough, staying very wet for to long - the pots were to big for the size seedling that they were and the soil mix was retaining a lot of water. As they have grown they have greened up nicely. So..........Id suggest when you water, do it lightly until they grow into the pots.

If they are larger - it may be a different issue. It does seem like a lot of fert for a very young plant.

I did read your earlier post. And mine are a little bigger. They have I would say at least 10 leaves and actually the leaves cover the pots. They are big leaves. That's why I thought maybe it was a fertilizer issue or my water. Just wondering if I should change fertilizer or water. I was thinking that maybe the fertilizer is too much too but just following a local greenhouse. Wondering if anyone else can offer suggestions on fertilizer or water issue. Or maybe something totally different. I do have a lot of plants in a area and have 4 fans going to circulate the air. I was always told and read that bottom watering was the best. But on your post it said to water from top. Oh man am I confused!!!!!

Water (amount of not pH) may well be a contributing factor in your case but no, bottom watering is no problem unless the plants are left to sit in water for more than the few minutes it takes to suck up what they need. Some folks just prefer top watering. *shrugs* In this case I'd be inclined to top water them too - for a week or so - in the hopes of flushing out some of that fertilizer.

Hard water from the well is much better for plants than anything from a water softener.

But I think the primary issue is that strong fertilizer. It is awfully strong for seedlings if used full strength, even for young plants. It's phos level can easily burn roots and burned roots = yellow older leaves on established plants. In a 4" pot no more than a 7-10 day feeding of no more than 1/2 strength fertilizer is required.

But with that particular fertilizer even half strength would be too strong. It would still be a 5-25-5 dilution. I take it down to 1/4 strength myself AFTER giving the plants a chance to recover.

If I am right you are going to lose many of those leaves to leaf drop. They will turn flaccid and drop from the stem. If that happens then you'll know for sure what caused it.

If you want to give the plants the best chance at survival, even with the dropped leaves - strip off the worst leaves and transplant them into new potting mix. Shake off as much of the existing soil as possible when doing so and plant them deeper into the new mix burying the bare stem.

Hope this helps.

Dave

PS: not a guru :) just nursery owner for a living.

So thinking I am going to buy some different fertilizer. What should I buy dig dirt? And what is a 7-10 day feeding. Sorry I'm new. And yes I think I do have that drop leaf thing. So I will hold off using fert. For a couple weeks and then buy some other fertilizer. What fertilizer you think s best. I don't really want to transplant over 1000 petunias again. Do you think they will die if I don't transplant? I will take a pic and show you what some took like. Thanks for help. I will post a couple pics

Here is another pic. Hopefully you can see how the middles are turning yellow in this pic.

Oh those don't look nearly as bad as described. Quite healthy in fact as far as can be seen in the upside down pics. :)

Yes perhaps a tiny bit of yellowing on new growth in the centers and that is water related primarily. Fertilizer damage shows up in older growth. You also have some leaf roll which again is water related - primarily inconsistent water/moisture levels in the soil - going from dry to too wet and back. I don't see any flaccid leaves just some roll and that is a physiological response of a plant to inconsistent soil moisture. It doesn't harm the plant but needs to be eliminated as much as possible.

New to this and 1000 seedlings! That's quite an endeavor but if they don't get any worse yellowing than that they will be fine.

7-10 day cycle of feeding is what I meant, no more often than that. Most seedling fertilizer is liquid and balanced (rated around 5-5-5 or 7-7-7) and is then cut to half strength. So try to find a liquid fertilizer that isn't so far out of balance as your's is or that can be diluted down to a relatively balanced level.

Dave

1000 wave petunias! Did you buy bulk seed? The waves I have purchased come 10 pelleted seed to a pack and are in the $3.00 range. I am too cheap to buy many of them. Last year I took cuttings from the waves as soon as I could and tripled the number of plants.

Yes I bought lots. I couldn't decide on colors. Then my sister said plant some for me and my girlfriend said me too. So by the end I have literally 1000 petunias. I have a very large yard on a farm and plant about 500 myself. I have ponds and all that stuff in my yard. That is why I am trying to grow my own petunias because it is getting too expensive to buy the plants. I am glad that I know what is wrong

Thanks for everyone's help and I think I will water from the top from how on so I stop drowning them. Thanks again

Since there us a discussion about fertilizing petunias what would be the best way to fertilize when there set up for self watering? Just add diluted fert, to water?