Answer: It would be better in terms of feeding the soil
to keep it weeded the old fashioned way, by pulling as
needed and then keeping the bed heavily mulched, but here is
an old time technique that may be worth trying.
Asparagus can tolerate a saline soil, which is why the
method seems to work. The salt kills the weeds without
damaging the asparagus. The question is, however, how
much damage is done to the soil? (Opponents of the
practice claim it breaks up the soil structure.)
According to what I have
read, as much as 1 pound of rock salt can be used per sq.
ft. but that seems rather extreme!
Here are the Rodale's Organic Encyclopedia
recommendations which talk of using salt, not for weed
control, but for the health of the plant:
"For healthy asparagus, add sodium chloride rock salt
(NaCl) to beds more than one year old. Apply 2.5 lb. per
100' row either before spears appear or around July 4.
Research shows this treatment helps asparagus resist crown
and root rot diseases caused by Fusarium fungi and also
improves overall growth. Don't use iodized table salt or
rock salt made of calcium chloride (CaCl). Pickling salt,
however, is fine for the job."
Q&A Library Searching Tips