Sunshine Mix #3

[desertlzbn]

Has anyone used Sunshine Mix #3 (seed starting mix), I have started several different types of seeds in it and it seems that they are not doing as well as when I started them in the Sunshine Mix #1, and it seems that it is weird and dry on top, but soaking wet on the bottom.
Does anyone know what I should do? Maybe admend it somehow?

[dice]

http://www.sungro.com/products_displ...d=5&brand_id=1

It is almost all peat moss, with a wetting agent, pH balanced,
some perlite and vermiculite, and no added fertilizer. Seems
to be working ok this year, but I am only using it in the
seed-starting cells. For potting up into newpaper pots
(equivalent to 3-4" pots) I amended it with 1/4 compost or
1/4 earthworm castings.

Where it dries out on top before seedlings have emerged,
I spray it with a solution of 1 part 3% hydrogen peroxide
to 10 parts water (moistens it and minimizes damping off).
I used that peroxide solution when initially watering the
seed-starting cells, too.

edit: I see that the web page above mentions "a low fertilizer
charge", but it does not mention that on the bag of LG3 that
I have.

[David Marek]

Always interesting to see how people use hydrogen peroxide. Desert, do you wet the mix before filling the pots/ trays? I have had that experience with bad batches of an otherwise good mix. It had a grayish, moldy look to it. When watered, the water would run down the sides of the pot- the bottom would be wet but the center was dry. I used aqua grow and had to water until it was thoroughly wet, a few drops of dish soap in your water might help. Let us know how they turn out.

Oh, and I don't like the "nutrient charge". The highest salt concentration is present when the seeds are trying to germinate (because it hasn't been washed out yet) and if they accidently dry out a bit too much when they are very small, the effect will be magnified.

[dice]

One probably would not want to use the peroxide solution
that extensively if using a seed-starting mix that includes
mycorrhizae or other beneficial microbe spores. They will
probably try to come alive as soon as they get wet, and the
peroxide will immediately kill any live fungi or bacteria that
it comes in contact with.

Hydrogen peroxide does not persist very long in the soil
or on plants. It reacts easily with organic matter, and
I would expect it to be completely gone by the next time
that the seedlings need watering (maybe a lot sooner
than that, like gone by the next day).

We have a wet climate up here at this time of year,
and damping off is a definite risk if one does not take
some kind of precaution against it. The mild peroxide
solution seems to work to prevent it. I add a dusting
of beneficial microbe spores on the roots when potting
up from seed-starting cells to newspaper pots or similar,
and once I have done that I cease and desist with the
hydrogen peroxide solution.

[desertlzbn]

I wet it well before getting it into the pots, because if I don't it never wets. I had two 6x6 cells that I put the mix into dry, and then tried to water on top, and through a bottom soak and they never even got wet in the middle. Now I pre wet everything. '

[dice]

I have had problems when packing it into cells or pots. Now I
just fill them loose, water from the bottom, and when I can tell
by the color that the moisture has reached the top of the cell,
I put in the seeds, dust a thin layer over the top of them, and
give them a spray to moisten that.

With the LG3 (claimed by the page at the SunGro URL posted
above to be the same as Sunshine # 3), the wetting agent
should overcome the hydrophobic nature of peat moss and
allow it to soak up water, and that is what happened this year
with my seedlings.

Maybe you got a really old bag of it, and the wetting agent
has lost its effectiveness (or they had a junk batch of wetting
agent and did not know it, or the nozzle that adds the
wetting agent clogged up for an hour, or whatever).

The advice to use a few drops of liquid soap in it is wise, that
usually improves the penetration of water into hydrophobic
(water repellent) growing media without hurting the seedlings.

[desertlzbn]

I opened the bag, and when it rained it got some moisture in it, so I am hoping that helps.