Ecnerwal wrote:
....
The supposed big advantage (other than not having hundreds of little
plastic pots/sixpacks/etc around) is "air pruning" - the idea being that
the roots grow to the edge of the block and stop, rather than growing to
a pot wall and winding all around. This is claimed to reduce (or
eliminate) transplant stress. I have not much to report on that front as
yet. The roots are also well-aerated as compared to a plant in a pot -
the soil is more compacted, but instead of a tiny hole at the bottom
which may be sitting in water, the whole surface of the block is exposed
to air.

They are a bit more fragile and fiddly to water than flats/six-packs,
but so far have held up better than I thought they would. Someone else I
know moves things around more than I do, and has had more problems with
blocks eroding or crumbling than I have (so far.) She is "not a fan" of
them, at least for herself, though she did like the air-pruning aspect.

i'd like it for not having to mess around with plastic
pots. there are other ways of doing sprouts that doesn't
involve pots, trays with slats to give spacing could work
too.

air pruning to me sounds like an interesting idea,
but isn't the point of doing starts to get the plants
to size ready to go outside? if the plants are getting
root bound then that means you've put the seedlings in
too small a pot. and that is why many places go from
smaller to bigger pots as the seedlings progress.

so basically, the air pruning is going to limit
the growth that you could have gotten if you otherwise
used bigger pots or plugs.


songbird