This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: Yellowing Seedlings/Plants

In a message dated 97-03-11 17:04:40 EST, Bob writes:

 
 <<What kind of fertilizer are you using?  From my experience, which is
organically
 orientated, I've found that a combination of fish emulsion and seaweed
 fertilizer is an effective feed, providing a good mix of major and micro
 nutrients as well as some plant hormones.  For seedlings mix up at half
 strength and feed once every ten days or so.>>

I used "Roots" to begin with.  Now, I give the tomatoes/tomatillos Miracle
Gro for tomatoes.  The rest get regular Miracle Gro.  1/4 tsp. per 2 gallons
of water every time I water.
 
 << No.  One cool and one warm is a good combination.  The cool provides more
light from the blue end of the spectrum and the warm more from the red end.
 Having
 both is more balanced and closer to natural light and plants' needs.>>

The puzzling part here is that I have 2 separate shelves set up for my
seedlings.  The shelving unit that has the yellowing problem has 3 sets of
lights, total of 6 48" bulbs, 3 cool, 3 warm.  The other unit, which doesn't
have any yellowing problem has just 2 lighting units, same 48" 2 cool, 2
warm.
 
<< While 12 hours is okay, much like the outdoor's daylight length, 16 hours
will
 give your seedlings more energy and encourage better growth.>>

Geez, where do you live?  We don't even have 12 hours of sunlight yet!!!
:-)))  Even in the summer we won't have 16 hours of sunlight!  I did increase
the timers to 14 hours.  I thought maybe I was giving them too much light as
I had them on for 18 hours per day.
 
<< The best growing temperature for most seedlings, and this is a
generalization,
 is 15-18°C.  If the soil temperature is too cool it can interfere with the
 plants' uptake of nutrients.>>

I have taken all the plants off of the warming mats as they are now all 12"
or better plants.  I usually keep them warm until they are transplanted.  I
only ones I left on abit longer were the canteloupe and watermelon.
 
<< Overwatering can leach out nutrients, particularly nitrogen and (I think)
 calcium.  As well, waterlogged soil displaces air at the root level.  Roots
 and soil organisms need some air too, particularly oxygen.>>

I may be a bit over zealous in this area, but thought since I have some
fertilizer in the water it would be ok. 
 
 <<Having some air circulation around the seedlings will help them transpire
and
 make them sturdier as well.>>

I put a small fan in front of the shelving units for a few hours each day to
help with air circulation and to increase the stem strength.
 
 
Thanks so much for your help Bob, I really appreciate it.  

Toni
Follow-Ups:
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index