On 31/05/08 09:57, Fred wrote:
Hello,

I don't know anything about weed killers so I've been reading a few
bottle labels. It seems that there are two types: one that kills
everything above ground and those that kill everything above and below
ground. The problem with the former seems to be that with the roots
still alive the plant re-grows. Now if that is the case, what is the
point of these above-ground only weed killers? Why doesn't everyone
just manufacture/sell/buy/use the above and below ground weed killers?


Well, the above ground killers (such as Weedol) are a lot, lot cheaper
and are good for quickly killing off annual weeds if you don't want to
hoe or pull the weeds out by hand. Annual weeds will not regrow from
roots if you hoe them.

The below ground weed killers are what you use to to get rid of
perennial weeds like nettle, dock, ground elder, bindweed, couch grass
etc as all of these will regrow even if you hoe them. But these types
of weed killer are much slower acting and a lot more expensive. The
brand name, Roundup, is typical of this type of weed killer but is
wickedly expensive. The active ingredient is called glyphosate or
glycophosphate , so shop around for the cheapest own brand available.
It can come as a concentrate (which you dilute) or as ready to use spray.


I understand that glycophosphate is highly recommended. B&Q's own
brand had a similar though not identical ingredient. Is that pretty
much the same?

It will be just as effective as the much more expensive Roundup.


I see that sodium chlorate is a cheap and readily available weed
killer. Is this an above and below or above only weed killer?

Sodium chlorate works above and below and is very effective as it kills
everything. But it can remain in the soil for up to six months which
would restrict any subsequent planting.

I'm looking for something to stop grass growing between the patio
paving slabs BTW.

Sodium chlorate would be fine for this. But you just need to be
confident that it is not going to leach out into areas that are
cultivated as it will kill those areas too.

The other alternative here is to use something like PathClear but that
seems like unnecessary expense. Other posters here might give a more
experienced view.


Thanks in advance.

No problem mate. But before you do anything... just read a few more
replies to your message in case I advised anything drastically wrong.

I don't wanna kill your garden!!

Ed