Friday, 29 June 2012

Dealing with the bindweed.(Calistegia sepium)

I do not like carpets on allotments because of the preservative chemicals that they have in them. However, the permaculturists say that you should always try to make something good out of a disadvantage.

There are a great many old decrepit carpets on the new allotment that I am going to use to cover the bindweed Convolvulus sepium - but I doubt very much if I will eradicate it.

Looking at various websites it seems that the rhizomes rarely go down further than 30 cm.  I don't doubt that the majority of the rhizomes rarely go down further than this depth but there are always the one or two that do.  Digging them out is the most effective method of control so this is what I am doing.  I am using my faithful bread tray sieve to sieve out all the little pieces.  Convolvulus sepium can regenerate from the smallest of rhizomes and it seems the aerial stems as well.  If you cover the surface stems they seem to change into thick rhizomes and continue to grow using food generated by leaves and stems that are not covered.

So, I am going to go over the whole allotment double digging to ensure that as much of the bindweed is removed as is possible.  I am putting the rhizomes into an old growing medium bag and then storing this in the  shed to make sure they dry off as much as possible.

A continuing difficulty will be the bindweed that is in the shared paths.  I am in a mind to follow the bindweed rhizomes under the paths in order to keep them off the allotment.  When I have done this I could replace the topsoil with stones that I am sieving out of the soil when I sieve for bindweed. Topsoil could go on the allotment and bindweed in the plastic bag while stones restore the level of the path.

The soul destroying information that the seed can remain viable for 39 years and can germinate even when 105 cm below the surface of the soil does not engender any confidence that I can get rid of this plant quickly.  Has this plant any respect for the RHS seed sowing advice?

Hey, isn't this what gardening is all about?

Overcoming problems is an integral part of gardening.  Crafting a weed free soil from one which is very poor or has innate problems must be an major achievement in gardening.

So back to the Convolvulus sepium - sepium means of the hedge.  I have a large hawthorn Crataegus monogyna ( monogyna means one seeded) hedge on one side of the allotment and the bindweed is entangled throughout it.

Keeping the bottom of the hedge tidy and free from weeds by hoeing and raking out is the only way that the bindweed is going to be discouraged from this part of the allotment.  I am going to put my sheds up against the hedge and this might prevent it from invading the allotment.  A forlorn hope but as Pope says "hope springs eternal."  A saying designed for gardeners.

It seems that you have to dry out bindweed for about 48 hours before it is safe to compost or bury it. Drying out large amounts of rhizome is quite difficult to do, but I will make the attempt.  I will bury as much as I can of the dried bindweed, however it must be done very carefully more than 60 cm below the surface of the soil.  I would rather cover the rhizomes in the trench with turf or some other difficult to penetrate compost such as leaves but I do not have these at the moment.  I may well cover them with the woody brush from the hedge when I cut it back off the allotment.  There is also a big gooseberry that is not producing any fruit so that will go into the trench too.

I will cover everything first with the sieved subsoil and then the sieved topsoil and hope for the best. The whole area will be covered with the pigeon manure and old carpets  and left to its own devices until next Spring.  

Then I have the problem of what do I do with the carpets when I have finished with them.  As is my wont I might just bury them.


  1. My method consists of pulling it out from the surface when it starts to climb on things. When I can find the time I use the head of a 4 tined cultivator as a hand tool and keep at it until I get to the root of things.

  2. I put it in a dalek. Only the very biggest roots sometimes come through, and they just go straight back in.

  3. This sounds more optimistic that I imagined. Not being experienced in the ways of bindweed, I thought that eradication would take a little time. While I would put it into the dalek to dry off, I still think that I would bury it more than 60cm below the surface of the soil. However, my dalek is full of nets at the moment so I will have to find somewhere to store those before I use it for bindweed.