organic / permaculture way of killing off kikuyu grass

[KYLYKaHYT]

Black plastic tends to work better for this, as it keeps sun light out, preventing photosynthesis. Black also retains heat much better, which cooks (and kills) all the little seeds and rhizomes in the topsoil. As for killing tree roots, I don't believe the heat penetrates very deeply into the soil. This could be tested with a meat thermometer. Nice video, BTW. :)

[Undersizeme]

Depending on your climate you should be able to stop invasion with...

cardboard cover, plant barrier of canna edulis and sweet potato in the tropics (other climates use other plants) and heavy mulch. Also instead of having trees in islands surrounded by kikuyu consider completely planting out areas excluding the grass altogether.

[zestoslife]

Thanks for that Sassafras, I was wondering if the heat would cook the roots. However hadn't considered the oxygen issue. Will make sure I don't go to close!

[SassafrasHomestead]

Just be careful and don't put the plastic on the roots of trees. Tree roots need oxygen and the plastic is not porous. It can actually kill the tree by suffocating it.