On 1/16/2021 8:02 PM, songbird wrote:
paul wrote:
azigni wrote:

In the end I turned over the soil every couple of weeks until everything
stopped coming up.

they say for scotch & spanish broom not to turn over the soil as the seeds
which last for 30 to 60 years will simply germinate more.

gotta be a better way somehow

if you are worried about soil disturbance and gemination then
i normally would use the smother and mulch approach as this means
not disturbing the soil or moving the seeds around. several
layers of cardboard with the seams overlapping by 9 inches or so
and then after that is down top it with some other mulch to hold
it in place. this may last a season or more depending upon your
local climate and conditions. it may not be that much work to
scrape the mulch aside and to repeat putting down more cardboard
on top of the old (leave the bits that are not gone as they'll
be worm food eventually) and then put the mulch back. i've yet
to have any plant last more than a few seasons once the top has
been cut back and then treated like this.

Some commercial agriculture use black plastic film anchored with metal
stakes. The area is irrigated first, and then the film is laid. All
this is done in sunny weather. Sunshine heats the film sufficiently to
cook any seeds and surface roots enough to kill them. However, this
works only for large empty fields, not for home landscapes where the
weeds are growing among desired plants.

The cardboard mulch idea can be used in small areas. However, it will
not eliminate certain seeds that can survive for years in the ground,
such as morning glory.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary