After months of removing weeds (mostly Kikuyu ..) from the vicinity of my natives, I have begun to think that I'd be better served by covering each plant with a towel and spraying the weeds. Its particularly painful along my fenceline : I hate whippersnippers, and they are too dangerous around my shrubs, but I'm concerned about the longer-term poisoning of my soil. Any feedback is most welcome.

Thanks,

Artie

With herbicides in general it is a matter of dosage as to whether or not the plant will be killed or even made signicantly ill. With Roundup in particular you really have to get close to 100% coverage before it will have a significant effect. Even then with mature trees and shrubs they would be more than likely to bounce back eventually from the thousands of dormant buds.

So you can safely hit a small proportion of mature trees and shrubs in attempts to kill the weeds growing under them. It will kill the leaves and green stems hit by the spray but it is highly unlikely that the whole plant will die, unless it was previously stressed perhaps. If you don't like the look of a few burned branches then just prune them off before or after spraying.

Where you have to be careful is with smaller herbs and lilies etc where there is much less biomass and therefore often much less coverage with Roundup is required to kill the plant. Aim to hit no part of them and have a spray bottle handy if you accidently do so.

As Roundup is particularly efective on grasses and other monocotyledons that don't have bulbs or tubers. So plants, like Dianellas, are particularly sensitive while bulbine lilies and chocolate lilies will come back.

You can protect small sensitive plants with milk cartons, soft drink bottles or tree guards and then spray the weeds liberally between them. Any weeds that are to close will have to be hand removed, cut & painted or herbicide will have to applied to the leaves with a paint brush.

Good Luck, mudlark

Thank you both for well-thought out, lengthy answers to my post - fantastic stuff.

I took great care to avoid spraying *any* of the native foliage when I sprayed the weeds yesterday, but I guess I'll really only find out in the coming week whether there was any 'collateral damage'. My previous experience (front fence) was initially positive, but I have lost plants in that area for no apparent reason, so I may have counted my chickens a little early.

Re the long term use of herbicides, it either that or take my neighbours to court. They dont seem to mind having grass of a metre or more along their side fence, and this naturally extends through the wire into my yard. I'm sure I'm not the only one who is envious whenever I see photos of gardens where the boundaries are 2 metre high brick or stone walls - talk about bliss !

Back to reality - I'll try to keep the spraying to a minimum, and try your suggestions re groundcovers, although I would have preferred my shrubs to have reached 2 metres before I bought in the ground forces :)

"gardens where the boundaries are 2 metre high brick or stone walls - talk about bliss !"

I know how you feel - if only I could afford that too!

You might also consider trenching the boundary and placing a plastic root barrier. I believe kikuyu roots can get reasonably deep. Also, what about placing a concrete strip at your boundary, say 200 mm wide over the top of the root barrier. That could at least place any kikuyu runners in plain view so that they would be more easily dealt with, by a spade if you don't like using a whippersnipper. (I don't have one of those either - I must be a reactionary because it seems just about every gardener in Australia has one - we're very "edge conscious".)

Cheers,
Frank

cheers, mudlark

In garden beds we also do not worry to much if we hit even a large number of Solanum seedlings in order to get the Gallium among them. We see Solanum seedlings popping up every where so the ones we kill will soon be replaced but the Gallium is a nightmare if it is let go.

It all has to be balanced with the limitations of running a business, limited time and limited funding for each job.

However there is little doubt in my mind that a 30 foot high gum tree or a 3 metre wide Boobialla will not be significantly effected if I hit one small branch. If they can survive a raging bush fires that takes out all the foliage then they can survive a minute does of Roundup.

I would also point out to artview that you can safely spray trunks and branches with Roundup as long as they are not green.

Do what you think you should do artview, prune the branches of your natives out of the way, tie them up out of the way, push them out of the way, pull the kikuyu runners (without breaking them) away from the foliage, protect the foliage of your natives with plastic bottles or bags or just put up with a bit of burned foliage BUT make sure you spray every last bit of the Kikuyu otherwise it will soon be back.

"With Roundup in particular you really have to get close to 100% coverage before it will have a significant effect."

This is simply not true, there are too many variables involved and it would have been quite remiss of me not to address it, particularly as we work in a similar industry. Your comments suggest that I was probably right when I wrote that no bush regeneration crew would have tested this theory....it flies in the face of what the conservation industry is trying to do; firstly in terms of protecting native vegetation and secondly in preventing the unnecessary wastage of chemicals, and thirdly in addressing the broader environmental burden of carrying a greater chemical load than is neccessary...even a chemical like glyphosate which has, in the past, had the myth of being a non-residual, low-toxic, quick-fix heavily promoted.

Respectfully, mudlark

You were right in hind site, perhaps "With Roundup in particular you really have to get close to 100% coverage before it will have a significant effect." was a bit too general. But it is certainly the case with Kikuyu and Couch and I have learned that from first hand experience.

No doubt smaller coverage will do significant damage to a native shrub and none of us want that. However again my experience thus far tells me it is unlikely to kill them out right even if you did hit 100% of them. Have hit some weedy shrubs and broadleaf weeds with roundup and it has had little or no effect on them.

Something like Garlon is far more potent and you have to be a lot more careful. But even then I have hit a small amount of mature shrubs unintentionally or unavoidably, been back later and seen that it has not had any lasting effect.

And any way this whole thing is about planted garden beds and not sensitive remnant sites. If there is any doubt or if it is practical then I always remove the branches in question anyway.