In article .net,
Priscilla Deverell wrote:

If anyone knows how to reproduce silver maple or maple trees period, could
you lend some of your expertise? Here's my story guys..........

Last spring, I decided to grow sliver maple trees from the seeds that are
produced from it's mother tree in my backyard. The seeds germinated quickly
and within a week or two I had new saplings (I think that's what you call
baby trees). However, after a few months they started dying off. Out of a
total of 20 saplings, 5 survived long enough to be planted in the ground
before winter. It is spring again and the planted trees are dead. I am
assuming I did not water enough and/or the soil was not deep enough in their
individual containers.

If I get a good system going, I plan to reproduce as many as 50-100 trees. I
am a beginner so any help would be appreciated.

I'd call these baby trees seedlings rather than saplings.

As you've noticed, silver maple seeds germinate readily when fresh.
The tree across the street from me tries to turn my garden into forest
every year!

I'd recommend that rather using pots, you plant directly in the
ground. Plant lots more than you need, so you can select the best of
the survivors in a year or two. The one catch is that you have to dig
them up and replant them annually to keep the roots compact. You may
need to prune off a tap root. Left to themselves, trees will spread
their roots widely, which means that they are hard to transplant
successfully if they haven't been root pruned annually. IIRC, root
pruning and replanting is best done in very early spring but this
varies with climate.

You can root prune with a sharp spade -- you don't need to work over
each root system in detail. Just cut out the seedling in a block of
soil and let it drop back into the hole, but transplant them further
apart when necessary. The basic idea is to keep growing fine feeder
roots close to the trunk, so the tree can be transplanted with a
relatively small ball of soil.

When replanting always prune rather than bend roots. Circling roots
can strangle a tree years later when they become large. This is one
problem with growing in pots, and there are special "root trainer" pots
for tree seedlings that divert roots downward and reduce circling.

It's easier to take care of the seedlings in a nursery bed than in
pots. In nature, the seedlings would grow in soil kept cool and moist,
with minimal abrupt temperature and moisture changes, under a heavy
mulch of leaf mold and dead leaves. In pots they get just the
opposite. Plant in good loose soil with lots of organic matter and
mulch heavily, especially in fall. This will keep soil conditions
steady and prevent root damage and drying from freeze and thaw cycles
in winter.

I hope this "backyard scale" advice helps. Growing trees from seed is
very gratifying. It's a pleasure to see a substantial tree that
wouldn't have existed without you, and which will continue to provide
beauty and shelter long after we're all dead. It's also particularly
good to grow native trees from seed. Too many trees people plant
are non-native species, often clonally propagated, which may not only
be more susceptible to new diseases and pests because of lack of
genetic diversity, but can become pest species themselves, as Norway
maples have become here in southern Ontario.