I had a chance to look at a greenhouse full of seedlings that are
being grown for 200 families in villages almost 100 miles distant
from our training center. The plants are not growing, and in various
stages of dying, and it's probably too late to save the crop. Here's
what I found was wrong - for starters.
The trays or flats were built with no drainage. This is the number
one No-No! Plants must have oxygen, and will drown without proper
drainage, or at the very least there will be a build-up of salinity,
which will totally stop them from growing.
The soil medium was more like clay soil than the soft and fluffy
sawdust, peatmoss, and perlite that we recommend. Even though
sawdust and sand were being used, the sawdust was truly DUST and the
sand was finer even than masonry sand. In addition, the soil was
pressed down firmly before planting. We recommend coarser materials
than that - again for the oxygen and drainage.
Pre-Plant and Weekly Feed fertilizers were not applied properly.
They needed 1/2 again the amount they had been given. For a flat 18"
square (1/2 meter) 1 1/2 ounces Pre-Plant and 3/4 ounce of Weekly
Feed should be applied and worked into the soil before transplanting.
The plants were planted too close together. This means more plants
are sharing the same amount of air, light, water, and fertilizer.
Most plants should not be planted closer than 64 in a 1/2-meter
square flat, and 56 is better. The ones I saw were all planted 81
The flats were also very shallow, which would become a problem soon,
if the plants happen to live. Plant roots need room, and a flat
should be 2 3/4"--3" deep.
Almost all plants were exhibiting deficiency symptoms of at least one
nutrient, and I believe several were needed. Purple leaves indicate
a phosphorus deficiency, and these needed that plus magnesium, and
probably calcium (the major nutrient in the Pre-Plant Mix).
I began by drilling 32 1 cm holes in each flat, and applied Pre-Plant
and Weekly Feed sufficient to correct the original deficiency. I
next aerated 200+ flats 1" deep by dragging a dibble beside every row
in both directions. I then applied the other two nutrients I felt
were needed immediately by including them in the first watering.
It would be very time-consuming, costly, and stressful to the plants
to transplant them into better soil medium. And I could not tell if
the holes were sufficient to solve the drainage problem - I suspect
they were not, mostly because of the soil medium being much too
dense. Sadly I had to leave more than 15,000 vegetable plants to
their fate, in the hands of people who know next to nothing about
their proper care.
I recommend anyone who is interested in growing their own seedlings,
which is very rewarding on several levels, should get the Mittleider
Gardening Library CD, which is available at www.foodforeveryone.org
in the Store section, and study Let's Grow Tomatoes and Gardening By
The Foot for starters.