more tomato problems from the newbie

[dan71314]

So, last week we determined that my seedlings were getting too much water. I stopped watering them so much, but the leaves remain yellow and it does not seem that they are growing at all. They are almost five weeks old and only a few have begun to set the first set of true leaves. My patience is being tested. I am sort of a perfectionist (so I am finding out) and I just keep racking my brain, trying to figure out a solution, but alas, more frustration. I am taking this too seriously, in mean, in nature plants are started all the time (most of the time) without the aid of us human beings. Anyway, can anyone tell me what is going on. Why are my seedlings refusing to grow?

[PaulF]

A couple of thoughts:

Is the soil mixture able to drain the excess water away and dry out a bit? You might consider pulling one of them to see the root growth. They may be water damaged.

The light source is correct and the time the light is on is also what it should be. The advise to stop the fertilization is also a good idea.

Or maybe you have not given them enough time to recover and they will be fine on their own. Good luck.

[dan71314]

Thanks Paul! The soil mixture is good; able to drain off excess water, dry out real well after a day. I did notice when I pulled one of the more yellow seedlings that the root system seemed very immature. There was one long root and all adjacent roots were short. I think that the light is ok; they are old aquarium plant lights, the full spectrum sort. I give them about 14 hours of light. Also, I have some okra seedlings that I started on the same day that I started the tomatoes and they seem to be doing well under the same light. Most all of my okra seedlings are showing good growth of the first true leaves. Again, thanks for the advice.

[amideutch]

Hello Dan and welcome. What type of soil are you using for your seedlings. Are you using 24" or 48" Gro Lux bulbs and how old are they? Are you growing them in individual cells in a seed flat or in individual pots? What is the temperature range in your garage? Alot of questions I know. Ami

[dan71314]

I am using Garden Safe All Purpose Natural Organic Potting
Mix for a growing medium, 48'' gro lux bulbs (they are probably 5-6 years old), and I was growing them individual cells, but once the first true leaves appeared I put them in individual three inch pots. The garage stays at a consistant 55-60 degrees. Thanks for the help Ami.

[mresseguie]

Dan,

Howdy!

Somewhere in this forum is a thread discussing the useful life of fluorescent tubes for starts. Most people recommend replacing the bulbs after each year's use. I economize a bit, so some of my bulbs are new and some are a year old. I might have a couple that are in their third year now, but I forget which they are. I shuffle my trays every few days to make sure they get good light.

I hope this helps.

Good luck!

Michael in OR. Zone 8.

[amideutch]

Dan, I would definately replace your gro lux tubes with some new cool whites tubes. You definately got the optimum temperature for hardening off the plants. That explains the slow growth of your plants. If nothing else maybe you could buy one of those cheap cold frames or make one and get your plants outside. Ami
http://www.gardengatemagazine.com/main/pdf/coldfram.pdf.

[dan71314]

I agree that the problem is the bulbs. I plan on getting to new bulbs soon. On the cold frame, what do you think of this: I set up an empty aquarium with the top open a little ways to allow air circulation. The temp is about 85 degrees. I would put my seedlings outside more often if the wind didn't blow on any day that the temp is nice. Do you think the aquarium will work as a pseudo-coldframe. One concern that I have is that the glass in the aquarium might concentrate the sunlight too much burn the leaves. Am I correct in assuming this? Has anyone heard of anyone using an aquarium the manner?

[duajones]

Last fall I sowed seeds in Schlutz seed starting mix. I had poor germination and slow growth. I resowed in a different mix and germination and growth were much better. The new seedlings caught up and passed the old ones in a matter of 2 weeks. I gently removed the older seedlings from their growing medium and put them in the different medium. They took off after that. Im not saying the growing medium is your problem but it was definitely an issue with me. Maybe the mix was old or something.

[amideutch]

Dan, have never tried an aquarium but have seen it done inside but not outside. I'd be leary of using it outside in direct sunlight as you suggested. Maybe repotting in a different mix as duajones has suggested is in order. Can't hurt but as he said it can help. The reason for getting them outside is the lighting issue and I'm sure the outside temps won't be an issue as long as the seedlings are protected. Ami

[RosaDawn]

Duajones,I too had a problem with the Schultz seed starting mix..this year..I have had to repot every seedling I had and put it into another soil mix and now they are growing.It took me three emails to finally get the attention of someone at Schultz and they blamed it all on me,they didn't even ask me to send them a sample of the mix I had.Just very snootily told me to send them the reciept and upc codes from the bag and they would send my money back.I don't want my money back,I want them to find out why seedlings do not grow in it once they are hatched...To prove to myself that it was their stuff and not me that caused the problem,i planted more of all the seeds i had started in their mix into some soil i had in a great pot from last year.Wouldn't you know it,they germinated fine and are now bigger than the ones I started in their mix.So,Schultz lost one customer as I will never use that stuff again.

[dice]

[instant cold frame]

I was browsing Craig's List, looking for tomato stakes,
etc, and I saw this post where someone was giving away
a garden window, the kind that is a little glass shelf that
sticks out from the house with glass on all sides but is
open to the inside on the largest side. It had what looked
like sliders on the two ends that would open to get some
air flow through it on hot days.

If one had one of those and just tipped it over onto the
open side, it would be a perfect cold frame. I don't know
if they all have windows in them that open to the outside
air, but some do. (If it didn't, one would need some way to
tip it up when the sun was shining on it.)

I see those things all of the time on there, though not always
for free (I don't know how they become unpopular once they
are installed, but some people apparently don't like them
and replace them).

[TZ-OH6]

The seed starter mix may have no nutrients in it, so once the energy stored in the small tomato seeds is spent the seedlings stall regardless of the light. Also, 60F is a bit cool, IMO.


At 14-16 hours per day the output of fluorescent tubes start to decline sharply after 8-10 months. This is important if you are trying to bloom high light species of orchids under them, so most of us orchid growers replace our grow tubes once a year, but even much older tubes will simply cause seedlings to grow a bit tall and spindly, not stop growing.


Cool white bulbs have a lot of (mostly) green output, to which the human eye is most sensitive. Plants can't 'see' green light, but get the most benefit-energy from blue light, and some red. Grow-Lux tubes have the best physiological output for plants, with energy peaks in the wavelengths corresponding to absorbtion by Chlorophylls A and B, and just enough green output so people are comfortable with them. If you want an off the shelf "white light" for your seedlings go for a 6000K daylight tube, which has the most blue output of the "people" lights. Just because it says daylight, don't assume the plant sees it as daylight. The color temperature (6,000k, 5000k, 4300k) is what is important. The higher the temp, the more blue is produced.