Re: Convolvulus arvensis -- oh lucky day!

Handpulling of bindweed is a waste of time, as it will
not get all of the living roots out completely, and
will quickly regrow within weeks.  Completely covering
soil with tarps and left on for several years will
also work, but doesn't eliminate the remaining seed
bank. I suspect that the regrowth of bindweed after 3
years of tarp coverage was from seed rather than the
roots...

I would also suggest that spring treatment with
Roundup is the way to go, and you will need to water
and retreat several times again to really kill all of
it.  Then even when you do have all the living plants
killed, there is still an incredible seedbank in the
soil which will continue to come up over the next 5
years.(I still have it coming up from seed 10 years
later in my own garden, but it is very manageable from
seedlings to control).

I don't think I would go so far as to remove soil, but
I would avoid planting in this area for the next
summer until you have a handle on the convolvulus.  I
would also suggest that if you need to get plantings
into this area in advance of complete control, that
you at least avoid plantings of things that will be
overwhelmed by the bindweed or make it difficult to
weed it out of adjacent plantings.  In this respect,
woodier shrubs or things like Agaves and Aeoniums are
great, as they shade the bindweed out by completely
covering the soil.  If you are planting anything
especially thorny and difficult to weed around, it
might be best to lay out weed fabric as a 3 or 4 foot
diameter barrier at the base of such plants.  This is
especially invaluable if planting things like
Dasylirions, Golden Barrel Cactus, Dyckias and
Hechtias, Puyas, etc., and also makes it easier to
handle more run of the mill type weeds as well. 
Mulching heavily to hide it also helps suppress weeds.

Wait to plant root spreading herbaceous perennials
such as Alstroemeria or similar, as it is particularly
hard to see the reinvading bindweed in such masses of
vegetation, or treat it effectively with Roundup
without extra effort.  Herbaceous groundcovers such as
Convolvulus mauritanicus or Scaevola, which don't root
as they spread can be planted out, as you can lift the
foliage off the ground to hand treat with Roundup any
bindweed.  Providing more shade in the long run is
also a rather effective deterrent to vigorous regrowth
of bindweed, it gets much weaker and less aggressive
with tree cover.  You will probably find that
cultivation of soil will continue to bring up new
seedlings even long after you have eliminated the
living plants, so mulch heavily to inhibit new
regrowth when planting out in this area.

I would be tempted to apply several treatments of
Roundup with new growth in early spring, retreat at 4
week intervals, and then rototill and irrigate several
times in summer, (at least rototilling twice with
irrigation in between), to bring up as many seedlings
as possible before doing any major plantings, other
than trees and larger shrubs. 

And be thankful that it is not combined with Bermuda
grass and Oxalis pes-caprae...


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