On 20/05/2012 19:02, Janet wrote:
In ,
says...
I seem to be overwhelmed by these two this year. Cleavers have always been
around in our garden (South Cheshire) but not to the extent that we have
them now and Rosebay Willow Herb has never been a problem before.
Is the weather to blame? Is there anything I can do to reduce the numbers
next year?
Cleavers are annual; they grow from seed every year then die. With any
annual weed if you prevent them re-seeding into your garden then the
population will eventually dwindle out. It's an easy weed to pull out by
hand.
RWH is perennial and can spread underground as well as by seed; the roots
survive underground in winter and regrow the next year. It also sets a LOT
of seed, so you need to both prevent it flowering, and kill off the roots.
Rosebay Willow Herb is another of these curious weeds that is sometimes
absolutely rampant and a serious menace or elsewhere barely able to eke
out a living. I have never been able to figure out whether there are
different cultivars of it or some soils do not suit it. Seems to be more
likely to go rampant in well drained fertile soils.
The one growing along railway lines is usually pretty rampant. But I
have seen in particularly in gardens up north with heavy clay soils
barely able to put up more than two or three shoots each season and
entirely self limiting in growth. Same for the low growing bindweed
(though not the more brutal common C. arvensis)
Keep cutting or pulling the stems BEFORE they mature; and trample on
the RBH stem stumps. That way you will prevent new baby plants germinating
from seed, and eventually starve the RBH roots to death.
The top growth of both weeds (without seeds) is excellent green material
for the compost heap.
Janet
--
Regards,
Martin Brown