Seedling leaf changes and death

[aclum]

Hi,

I've been having problems with some of the seedlings I have hardening off and awaiting plant out in the garden with improved weather.

Seedlings in 3, 5, or 8 oz cups with drainage holes, filled with DE and lightly fertilized with Urban Farms Vegetable Fertilizer. Greenhouse temps 50 lowest a night and up to around 80-85 during the day with ventilation (sides rolled up, doors open). Filtered sun through shade cloth as well as some direct sun.

The seedlings will start out normally but over time SOME (10% ???) of them have developed curly, more rugose (sp?) leaves - particularly on the top - that gradually get crispy and brown and die. They have adequate water. It seems to affect mainly the plants with more sun exposure - but I wouldn't swear to this.

The greenhouse cover is a blue solar swimming pool blanket (like bubble wrap) with roll up sides and additional 6500K fluorescent lighting provided about 10 hours a day (although sometimes longer if I have the digital timer set wrong).

Any ideas what might be causing this? (BTW, haven't seen any insects that might be causing damage). Sorry I don't have any photos at the moment.

Thanks!
Anne

[aclum]

Hi Again,

Here's a link to a recent thread I did with photos of the greenhouse - so you can understand the set-up a little better:

http://www.tomatoville.com/showthread.php?t=31270

Anne

[Labradors2]

From my recent experience, I would say that crunchy leaves might indicate too much fertilizer.

Linda

[aclum]

Hi Linda,

Thanks for the response - and sorry to hear about your "recent experience."

I think you're probably right about the overfertilization. I recall reading that you couldn't really overfertilize with the Urban Farm product, but maybe I fertilized too often or the small containers were a problem.

Unfortunately, I fertilized my seedlings again yesterday when I watered! So I just went out and watered everything again (particularly the plants showing any signs of distress) really well, hoping to flush out at least some of the excess fertilizer.

Fingers crossed!

Anne

[Labradors2]

Anne,

You might be better with half-strength ferts on the seedlings in the future.

My plants survived, it was mostly on the potted broccoli, but the affected tomatoes survived. I hope yours do too!

Linda

[Worth1]

Anne if the leaf tips were turning dark before crispness set in it very well could be to much fert.

If it is then you need to flush about 10 times the amount of water that the container can hold.
Another option would be to remove the plant from the container and wash the root ball off and replace with new soil.

Sort of like Bypass surgery.

Worth

[aclum]

Hi Linda and Worth,

Thanks for the encouragement and advice, although, Worth, I think your recommended remedies are perhaps more akin to a pre-colonoscopy colon cleanse or an organ transplant than to a heart bypass !

I just reexamined one of my afflicted plants and the curled top is darker than usual - but more of a VERY dark green rather than brown or black. Also the top leaf group (most of the lower leafs have dried up and dropped off) has a curl like a hand making a downward claw-like grip - if that means anything as far as diagnosis.

Fortunately, I have (generally) ungrafted back-ups for all but a couple of the varieties I've lost. (Most of my plants are grafted this year). I'm not all that concerned about some of the losses as the person who I normally give quite a few plants to told me he doesn't want any plants this year! He prefers the ones "like you get in the grocery store" and is going to pick up a couple of Early Girls and Big Beef at Lowes . He told me that last year he just had too many tomatoes to pick and finally had some friends who own a Chinese Restaurant come over and pick all they wanted!! Sheesh!

Now I have to find some new willing vicitims for my gift of plants. If I have many leftover, they'll no doubt be making a trip to Dr. Frankenstein's grafting lab !

Anyway, thanks again for the advice - I'll go easy on the fertilizer next time!

Anne

[amideutch]

(Most of my plants are grafted this year)

So is this top growth leaf curl happening just on the grafted plants?

Ami

[kurt]

Same thing happened to me with the Urban Farms.It is a good fert but I did notice when I had a small paper cut on my hand the stuff burnt the bezeesus out of it.Even one my full grown two year old Trinidad Scorpians it seems to change the leaf structures somewhat.I think it might be the urea in the bat guano.

[aclum]

Hi,

Looking over things this morning, there seem to be a few tomato seedlings that are pretty much goners but, overall, drenching the plants with fresh water to flush out some of the excess fertilizer seems to have helped. There don't seem to be any newly afflicted plants and the ones that were starting to show signs of affliction seem to have improved somewhat.

Ami,

I've got over 150 seedlings going and haven't been keeping records on things, but I'm guessing the dead or dying seedlings were about half and half grafted vs. ungrafted.

Kurt.

That's interesting about the UF Fertilizer. I scanned through a bit of the "Urban Farms Texas Tomato Food" thread (in General Discussion) looking for where I might have gotten the idea that it was hard to overfertilize using it. I came across this in post #57:
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This reply is in reference to your containers, to help you dial-in your feeding frequency. If you notice on the backside description (upper RH block), it says TTF is designed as a "continuous feed" nutrient for containers. I want to qualify that.

This is true if your container mix is inert, that is.....a soilless medium without any existing NPK in it. When using this kind of medium, you can use TTF continuously as long as you overwater each time by 10-15%. In this situation you are essentially practicing "manual hydroponics", so that is where our fertilizers will really shine, because they originated as "continuous feed" hydroponic formulas.

However, if you have added nutrients/compost/manure/etc to your mix, that means there is a varying degree of NPK already in the rootzone. In this situation we recommend feeding every 2nd or 3rd watering. Watch your plants. Ultimately you have to let your eyes tell you when to give them a "shot".

In soil, the general rule is feed every 3rd watering, but this is negotiable. It is difficult to over-fertilize with our nutrients, so you can get away with "pushing" your soil plants with 2-3 shots in a row. But then back off to pure water for 2-3 waterings.
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"Bolding" mine

Based on my experience, it does seem possible to overfertilize using the Urban Farm products. Live and learn. I'm still planning use the product - just not so much - and switching over to the tomato food once the seedlings are transplanted into the garden.

Anne

[Cole_Robbie]

Originally Posted by aclum

The greenhouse cover is a blue solar swimming pool blanket...It seems to affect mainly the plants with more sun exposure

Maybe the pool cover is not made to block UV light like greenhouse film is.

[aclum]

Hi Cole,

Sorry not to reply sooner (been busy planting out ). I doubt that the pool cover blocks UV to any appreciable degree. It's advertised as keeping the covered pools warm. I monitor the greenhouse temps and it's never gotten over the high 80's - and then just for a brief period of time. (I've been opening the doors and side flaps when it gets warm and can turn on fans if necessary).

There's shade cloth underneath the pool cover, so that would cut down on any UV penetrating the pool cover somewhat. Would too much UV cause the curling leaves I described??

I was wondering a bit about the blue color having a negative effect on plants inside the greenhouse, so I supplemented the light withl 6500K fluorescent lighting.

All in all, I suspect that the pool cover isn't the problem and am going with the over fertilization theory for now.

Anne

[Urbanfarmer]

Hi.... just saw this thread. As a manufacturer there is some risk in getting involved in consumer threads, but, hey, we're a small company........personal interaction with our customers is part of what we do. We can either stay above it all or jump in and try to solve problems.

Poor results aren't something we're familiar with, so something is up. Initially it sounds like overfertilization. It's easy to do with seedlings and temps in the 80's.

The very first thing I would ask is.....do you shake the bottle well for 3-4 seconds before every pour? That is essential. Even more, if the bottle has been sitting for months, especially if it got cold/freezing, then you have to warm the bottle up and shake it for up to 3 mins. Then it will be good-to-go again. It looks very much like chocolate milk.

The second question is......have the rootzones dried out? This will concentrate nutrients to the point where it's the same as over-fertilizing.

Third......what size are these seedlings? Under 6" tall and you should only be running at 1/2 strength (1/2 tbls/gal), and only feeding intermittantly, say every 3rd watering.

The part about "It's difficult to overfeed with Urban Farm Fertilizers" only applies to a soilless medium and every irrigation is a full flush. In soil or containers you can only feed intermittantly, again such as every 3rd or 4th watering.

With larger plants, your eyes will tell you when to feed. We can only generalize on our instructions because situations vary so much. If you see deep green, prolific foliage, you know it's time to back off the food. When the vibrant growth begins to wane, it's time to feed again.

Hope this helps.....

[aclum]

Hi Urban Farmer ,

Thanks for posting! Yes, your information certainly DOES help and I can see a bunch of ways that I might have gone wrong with the fertilization. I know the fertilizer itself was not problem (I've just read great things about it), but rather how I used it.

I shook the fertilizer container what I thought was really well, then poured half of it into a empty plastic water bottle with one of those pop up tops (like you see on dishwashing liquid containers). Looking back on it, it seems that the liquid from the original container might have been getting a tad thicker as I proceeded to fill the water bottle. In retrospect, I probably hadn't shaken thing up well enough. So I probably need to recombine things and shake everything up again really well.

My seedlings were definitely under 6," I ended up using nearly full strength (1/2 TB per 1/2 gallon jug of water), AND I did let the roots dry out (having been warned numerous times on TV about the dangers of overwatering).

So, it seems like I did about everything wrong ! (Except I did shake the fertilizer in the water bottle EACH time I used it).

So my plan now will be to recombine the concentrated fertilizer in the original container and water bottle and make sure everything is REALLY mixed well and then transfer some to the sports bottle for easy measuring and pouring. I have a little glass "graduated cylinder" (I think that's what it's called) to accurately measure out small amounts of the fertilizer. When I do fertilize, I'll just use half strength and over apply so the root zones are saturated and excess drains out.

Am I correct in understanding you to say not to let the roots dry out at all? If so, I guess I should have my containers set in a tray of shallow water? And, I'll just fertilize every 3rd or 4th watering as the potting medium starts to dry out - but doesn't get bone dry. (I'm using DE as the potting medium, BTW).

Hopefully the problem was over fertilization and not something else, and I won't run into any more problems.

Thanks again,
Anne

[b54red]

Anne you won't find a bigger fan of DE in seed starting than me but it has real drawbacks when it is used when trying to harden off seedlings. I have used it successfully but I have also run into problems with it when it was too hot and it dried out too much. I swear it looks almost like it can actually suck the life out of the plant if it dries out completely where as the plants seem to recover fine when the medium is potting soil. I find using larger containers of DE much more difficult to manage than when I am using it for seed starting because they don't bottom water as well as small containers of DE and it is hard to tell if the DE is too dry once the surface gets a little algae stain on it. I killed a bunch of onion seedlings last year when I let the 8" clay pot they were in dry out too much.

I am potting my grafts up into moist Optisorb as I graft them and then put them in the healing chamber and it has really helped prevent damping off in the healing chamber. When they are ready to go outside to harden off I am re-potting them again into cups with potting soil. I have left a few in the DE but I have to keep a close eye on them as they are tending to dry out far too fast when exposed to the sun and wind. We haven't even had a hot day yet so I may pot the rest up into pots with potting soil because even though it was only in the low 70s today the DE cups were very dry after being well watered just 24 hours earlier. When the plants are that small they don't remove the moisture that fast so it is obviously evaporating much faster out of the cups with Optisorb than the ones with potting soil. I like letting my tomatoes dry out for added root vigor but I don't like some of the effects of letting them dry out when they are in DE. I imagine with your low humidity in California that the problem would be even worse.

My grafted and ungrafted seedlings have been getting a weekly dose of Urban Farms Apples and Oranges which is very similar to the Vegetable fertilizer which I used last year with good results. I give mine about a 1/3 to 1/2 strength feeding about once a week but they get watered 2 or 3 times between feedings and I have had no problems. When they get out in the garden and get to the early bloom stage I will start giving them a weekly dose of TTF. I usually start off around half strength when the plants are small and increase the strength as they get larger and also the overall amount. Whenever they get really dark green I will reduce the dose or just give them plain water until they look like they are ready for more.

Bill